If you have a Central Pneumatic air compressor, and you didn’t buy it used, from a garage sale, or from on on-line end-of-line wholesaler, odds are pretty good that you bought it at Harbor Freight.
In 2017, Harbor Freight offers about 35 different Central Pneumatic air compressors, from a 1/6 HP air brush style to a 5 HP, almost commercial type, on a 60 gallon air tank. They even have one model of a gas-powered, wheelbarrow style, that is quite well priced.
Central Pneumatic air compressors can be purchased through Harbor Freight on-line, or at the many Harbor Freight stores found throughout the United States.
Buyers of Central Pneumatic air compressors are, pretty much I think, aware that you get what you pay for. This line of compressors is entry level. I don’t believe they are made for serious compressed air use, where whether or not a compressor works means that trades persons do or don’t do work that day.
Which is not to say, if you are a periodic user of compressed air – the typical small workshop or home garage for example – you won’t be happy with this brand of compressors reliability. I just wouldn’t put the supply of my plants air system at the mercy of this particular brand.
While Harbor Freight boasts of having manufacturing around the world, I would be surprised if they actually owned a factory that makes air compressors. Their entire line is similar or identical to compressors of other brands with different colors and different labels. I could be wrong and will be happy to indicate so if someone can provide proof that HF actually makes their own compressors.
Regardless of whether they make them or not, try to find parts for a Central Pneumatic air compressor. Aside from pressure switches, gauges, regulators, PRV’s and check valves (all the same as those found on many other brands) there are very few repair parts for the compressor pump or the motor. Parts from other Central Pneumatic air compressors can often be used on other models of this brand. If you can scrounge or buy a non-working compressor, some parts from the old can be reused to fix others that have failed. Depends on your skill level as to whether or not this works for you.
If you are having a problem with your Central Pneumatic air compressor why not add a question or comment here? Include the model number of your compressor. As a result, perhaps the Central Pneumatic air compressor owner/user family, which is a huge one, can offer advice as some of them will, undoubtedly, already dealt with the same problem you are experiencing with your HF Central Pneumatic air compressor.
I just got the 3 gallon oil less pancake compressor. Is there a way to lengthen the amount of time it will run between refills? I’m in a small room using it for art and it o my has a 20 of pressure difference between full and needing to refill. Can I adjust that down a bit so it doesn’t refill as often?
Thanks
Rachel
The first step, if you haven’t done so already, is to dial down the pressure on the regulator to the lowest pressure setting that will work for you.
The next step is to take a photo of the parts page that shows what pressure switch this model of compressor has, as if we can’t see it, we don’t know if it’s adjustable. Please add a photo in your response to this thread.
I have a Central Pneumatic 67696 150 psi 6 gal. Have had for years and been pretty good. Now when pressure gets up to 150 psi in tank, PRV let’s go and it never shuts down. Only way I can use it is to shut off compressor once pressure gets up to 130 or so. Is this a faulty PRV? A fiend told me some tube which signal compressor to shut off might be kinked or need to be replaced. I’m not too mechanical but can follow You tube to fix something. Appreciate any advice!
Is 150 PSI the normal cut out pressure, or is it lower? If the normal cut out pressure is 10-15 PSI below the 150 PSI where the PRV is letting go, it’s quite possible the pressure switch that’s failed. If 150 PSI is the normal cut out, and the PRV is letting go at that pressure, then it’s quite possibly the PRV.
Dump all the air with the compressor off, remove the PRV, rinse it in thinner or boiling water, dry, and test again. If it is still cracking open at or before the normal cut out of the compressor, replace it.
Thank you Willyr! It’s supposed to cut out at 150psi. I’ll try removing and cleaning the safety valve and if that doesn’t work, replacing it. Appreciate the advice very much!
You are welcome, and let us know how it turns out, will you?
I decided to buy a new safety PRV and replace. The new PRV works “better” as it blows at about 155psi and the closes back at 120psi. The old one would just stay open until the tank drained. So I’m guessing my problem is the pressure switch not shutting off the compressor at 150psi. Don’t have the tools to get the cover off so guessing I’m stuck with what I have or bring it somewhere to have it repaired. Or find the right tool (8″ or so drive to reach hex head I’m guessing?). Thanks again for the help!
There’s a bunch of comments and posts on this site about getting the covers off low end compressors. If you use the search function at the top of the nav column, you’ll find them. And yes, often the hex bolt is metric in size and needs an extra long wrench to reach the head.
My model 95275 3 gal compressor won’t start. Is there a fuse?
It had worked fine for years but today I plugged it in and nothing .
Mike, you need to do a few checks. When you do, please add a comment. Not sure which? Try these pages, all found linked from the compressor troubleshooting page on this site.
air compressor will not start
air compressor cycles on and off all the time
air compressor just hums
air compressor will not start when cold
compressor trips the breaker when restarting
compressor will not restart when air is used
I have a 9gal wheelbarrow type and it suddenly started shutting down once it reached top pressure instead of throttling back to idle and cycling on and off. Found the pilot valve shaft was slightly bent and replaced that, but it is still shutting down. I’m now wondering if it’s something to do with the throttle control.
I’m no expert when it comes to gasoline powered air compressors Darrell, yet it certainly makes sense that if, instead of throttling down to idle when the tank is full, the Central Pneumatic compressor (what model is this, by the way?) shuts down.
Please identify the model number, and add a photo of the compressor in your response to this please.
Bought a 1/3 HP hot dog compressor Central neumatic from HF store used 6 times to fill pool toys and my car tire; Now it does not build pressure, never again will I get Peumatic Comp again ; I guess you really get what you pay for.
Mostly, huh? B.
trying to find a replacement tube, the one from motor to tank that has compression ring on either end. mine sheared off after I attempted to tighten the nut. what kind of store sells aluminum or better yet copper flexible tube and compression rings? 3gal 100psi pancake
I suspect that if you took the fittings and the tube to a good industrial plumbing or compressed air supply shop, or an auto parts supply shop, they’ll be able to fix you up with a custom one, made for the compressor.
The air outlet that attaches to the hose broke off
Thanks
Howard
Howard, I call that outlet the discharge coupler, if I’m guessing right about what you are talking about. Please see this page: https://fix-my-compressor.com/connecting-your-air-tools/.
If you go to the hardware store where you buy pneumatic stuff, you can get coupler and connector kits there. They are usually under $20. Remove the broken part of the old coupler, install a new one, and if it fits the connectors you have that’s good (it probably will) but if not, replace the connectors with ones from the new kit as they will be compatible.
My grandfather recently bought a 2.5 HP 21 Gallon compressor and forgot to put the oil in for initial use seizing the compressor. I since then have gotten the compressor running although it will only occasionally build pressure, and even then it only gets to about 20 PSI. I took the top of the cylinder off and the small metal plates now refuse to stay in place. Is there something else I need to do to get it back working or should I just replace the compressor with another that I have?
While I cannot see the compressor or the “plates” (flapper or finger valves I suspect) it sounds as though heat may have warped them. Find parts or trash the compressor? Depends on how much time you want to spend, parts cost if you can find them, and the urgency, I guess. Good luck.
I have the 21 gallon CP 2.5 HP model 61454. I recently replaced/repaired the reed valve and was working fairly well. Then a couple days later I noticed it kept running and would not go past 90 psi. Someone told me it might be the pressure sensor, but want another opinion form someone that may know from experience. Also if it is the pressure sensor or something else, where can I buy the right part?
Sure Aurelio, this issue is covered in detail on the pages of this site. Check the troubleshooting page, and read the pages that relate. If you still have questions, please add them as a comment.
I have a friend who has a Central Pneumatic Model# 95386 air compressor.
It is having and intermittant problem of the reset switch operating and having to be reset to get it started. When it starts again, it runs very slowly until it eventually trips again.
Sometimes it will run normally and stay running at the normal higher rate of speed and then eventually return to the slow speed until it is stopped by whatever it is that is tripping the reset. Any ideas as to which direction to look to solve this problem?
Sounds like it is plugged into an extension cord that is not heavy enough.
Assuming there’s no change in location, and the compressor worked there before, see the information on this site about checking the capacitors. The symptoms suggest the compressor start capacitor may be failing.
Where can I get a regulator assy for a Central Pneumatic 95275 compressor?
I think when you pull the cover off you’ll see something like what is shown in the image uploaded. That’s a manifold, and I don’t believe parts for it are available, or if you can even find the manifold.
The solution is to assemble your own from standard brass fittings from a decent plumbing supply house, and replace the regulator that came with the unit with a general purpose mini-regulator (typically 1/8″ in port size, at a cost of about $15 for the new regulator. Then, if you have regulator problems again, it’s easy to get a replacement. Good luck.
The image was a “screen grab” from a you tube video by Don Brandt about repairing a Central Pneumatic compressor. The video can be viewed by following this link.
I have a problem with a central pneumatic (Harbor Freight) 29 gal oil lubed unit that will build pressure fine until it reaches ~100 psi then it starts to “strain”/”lugs” and motor ( single phase induction 120v) begins making some “ticking/clicking” noises and unless I turn it off manually it will trip the breaker in the panel ( never the motor reset).
I’ve replaced the run cap-(did not fix). Tank check valve seems ok ( no visible signs to indicate faulty and no air leaks from anywhere when tank pressurized).
Unit is supposed to cut out at 150 and back in at 120.
I purchased the unit in this condition (used- barely-it looks brand new so obviously hasn’t seen much use and seller didn’t have much history about it). What else could it be? Thanks in advance.
20 amp breaker. Panel to outlet is ~ 25′.
Thanks for the info. I expect your compressor is 1.5-3 HP in motor size, and as such, the power supply should be more than adequate.
If it’s not the power supply to the motor, it must either be an increasing load due to air pressure building, a mechanical issue backloading the motor, or the motor itself. That it’s popping the breaker at the panel and not the motor cut out says to me that it’s not a heat issue (the motor would trip out on thermal) but is load related.
It were mine, it would be time to pull the top off the pump and check the valves.
My first thought is power supply. What’s the breaker amperage, and what’s the distance between the panel and the socket?
Had my 125psi 2.5 hp 21 gallon central pneumatic lil over a year NEVER BEEN HAPPY DOESNT NEAR ENOUGH AIR. Also the cold start valve went out as they ALL DO !
Went to replace it and never got valve screwed all the way in until the housing on the compressor snapped into. BEFORE YOU SAY I OVER TIGHTENED, I’M A CERTIFIED PRECISION STEAM TURBINE MECHANIC I KNOW ALL ABOUT TORQUE SPECS AND EXCETRA.
TERRIBLE PRODUCT WILL ( NEVER BUY ANOTHER ONE ! JUST SCRAP NOW!!
RATE 1 ☆ ROBERT RAY MOUNT PLEASANT,TX.
I purchased a Central Pneumatic 67696 Air Compressor several years ago. A few weeks ago it would not shut off at the high pressure level approximately 150PSI. The PVR goes off and the motor does not shut down. I ordered a new switch thru Amazon. It arrived yesterday after a week delay and got it installed. Nothing has changed. Any suggestions.
Is the PRV is letting go too soon? What pressure is the PRV letting go at? Note that the air gauges can be out of range by +-5 PSI.
It’s that or you have a bum switch. There seems to have been a lot of complaints of that going around recently. Possible a bad batch by the Chinese plant.
Thanks for the info. Will try to locate a new PRV. If that doesn’t work I’ll try better gauges. If they cost too much, I’ll just fill the tank and shut it down.
I bought a central phumatic twin cylinder 145 psi pump 1 year ago with a new 5 HP electric motor 3450 rpm. I did the math from the HF manual and installed 4.5″ pulley on electric motor. I just started to build the air compressor a week ago June 10,2020 the parts have been in my garage shrink wraped until I needed them . After several configurations of the 3/4″ tubing that i replaced from flared copper to compression stainless steel and installing new tank check valve 3/4″ with a a 90-145 psi pressure switch all I can get out of my compressor is 25 psi. I have a HD 60 gallon tank. The pump gets close to 25 psi and slows to trip the electric motor if I dont throw the on off switch. I have changed the start capacitor and run assist capacitor with no change. Checked the reed valves were all good and put new gaskets on the valve plate and head.i changed out 2 different pressure switches and 2 capacitors. I am out out ideas and watched videos asked people at HP and everone tells me to change the parts I have changed please can some one help me .
It sounds like a power supply issue, that or loading on the pump from increasing air pressure is overcoming the motor’s ability to drive against it. Help others help you and tell us a bit about the power supply to the compressor from the breaker at the panel to the compressor, won’t you?
I have a 3 gal oiless pancake compressor. Central pneumatic. I am looking for the regulator for this compressor model 60637. Any help.
Please, in a comment, add a photo of your compressor and the current regulator. Thanks.
(I need ) the red pressure knob and valve assembly on the regulator manifold from the tank.
Hi Bill. Got this one photo, anyway.
If it were me, and knowing that parts for this regulator are few and far between, I’d simple replace the whole assembly with brass fittings from a decent plumbing shop, and then install instead of the junk that came with the compressor, and off-the-shelf 1/8″ regulator available almost anywhere for peanuts.
I have model E 99780. It runs and builds pressure but does not hold pressure. New hose and fittings. Still does not hold for very long. And it is taking along time to build pressure.
It’s hard to tell from the drawings (no pictures) I’ve seen, but I believe the mini-pump on this compressor pumps into the tank via a valve. This valve is item 20 on the parts list. This valve should both allow the air from the pump to enter the tank while the compressor is running, and also keep the air in the tank while the compressor is off. That compressed air is then accessible to the filter / regulator manifold at the front of the compressor via the tube from the tank there.
If my surmise is correct, in that valve is a flapper or check, and if that flapper or check is not seating tightly, air will escape. You need to find that valve and check it I believe.
If you have no manual they are available on line.
I have the 21 gal model 61454. Less than 2 months old. The reset keeps popping when its time to fill ? Start of day. Motor not hot. Tries to start then pops? Any ideas?
A bunch… try these first.
– https://fix-my-compressor.com/compressor-trips-the-breaker-on-restart/
– https://fix-my-compressor.com/is-the-compressor-start-capacitor-working/
we have ran these tests.The air compressor turns on and fills to 5 psi and then shuts off. We have to push the reset to get it to run a little more. We have drained the tank unplugged watched for the arching and sparking (which there is none) It plugged straight into the wall.
I would think from the symptoms described, the start capacitor is weak or failing. Please go here: https://fix-my-compressor.com/air-compressor-problems-and-fixes/ and scroll down and look at the pages to do with capacitors if you aren’t sure about what they are.
Where is the shaft cap and centrifugal switch on this if there is either? Also where would I get the same motor or one that works better yet is compatible to this compressor
Model: 61454
21 gallon
125 psi
Typically the centrifugal switch for an electric compressor motor is on the shaft end that connects to the drive. It’s normally under the cap, and looks like this.
If you aren’t seeing this, then your compressor motor doesn’t have one. Time for a motor load check at a repair depot.
Hey there. I got the 69091 model 21 gal 125 psi air compressor. I let it sit outside forgetting it was there and didn’t change the oil. I ran it for about a year here and there doing small stuff but this week I turned it on and heard a snap and the motor went to running super smoothe. The connecting rod broke.
I need to know if there is a replacement part for it and if so a part number. I can’t find one. I’ve emailed hf and no answer yet. I’d like to fix it if it’s available. Its been a great small compressor. Thanks for your input
Parts for this model of compressor available from HF are here. Otherwise, you may be out of luck and may need to get the connecting rod made for you.
I bought a compressor used and doesn’t have a manual. How do i find a model number. Can you help
What is the HP of the compressor you have, plus, if you can find out, the tank size?
Go the the Harbor Freight site and see if that one is there.
Or, Google Central Pneumatic compressors (adding the motor HP and tank size) and see if you get an image back of yours. That may help identify the model.
Adding a couple of photos of your compressor in a comment on this thread wouldn’t hurt.
Here are some pics. Psi 175 max
Thanks for the pics.
It would appear as though yours is an older version of the currently available C201H. If you go to the HF website and look for this one, you can download from that page the three manuals of the various iterations of this compressor. Please check and see if the info you get from them is what you are looking for.
CP model#61454
Looking for part #15884
Reed valve rebuild kit
You have checked with HF to see if they’ve got it? The 2019 manual for this compressor shows that it was available from them then. REPLACEMENT PARTS IN STOCK
Call to Order: 1-800-444-3353
Will this capacitor work as replacement for stock one? The second picture where am I holding it with my hand is the stock one
Compressor model 61454 2.5 hp 21 gallon
Specs on possible replacement: 140 microfarads 250 VAC
As the page says I believe, if the micro farad specs are comparable, if the voltage range is comparable, and you can actually fit the new cap in the location where the old one was, then you’r good to go. It appears as though the new cap meets those criteria.
My compressor still won’t run and there was no improvement from the new capacitor. I replaced the capacitor on my central pneumatic compressor and I believe the old one was good still , could it be the motor or some other part I can replace, I don’t believe it’s The on/auto switch, I replaced that already and the one I had on before worked fine before The compressor just buzzes and no rotation of the compressor. Even when I try to get it going by pushing the fan and removing the cold start valve, it still will not continue or start running.
Model: 61454
Power: 2.5
21 gallon tank
125 psi
Darn, Emmett. Yup, if the start cap doesn’t resolve the issue, and the motor is trying to start and it’s not doing so, then it’s a motor issue. If you know about electrical motors,pull the shaft cap off and see if there is a centrifugal switch. If that’s locked up that may be the issue. Failing that, it’s time for an electric motor shop I would think.
Hi, my harbor freight air compressor is not turning over, the motor refuses to spin, it buzzes and then the fuse will get tripped, not sure what the problem is. Hasn’t been used much at all.
Model 61454 21 gallon 2.5 hp pressure switch 125 psi
Where do I get the exact start capacitor for my model air compressor
Model 61454, 21 gallon, 125 psi, 2.5 hp
https://fix-my-compressor.com/finding-a-new-compressor-capacitor/
If it was working where it is before, and the power supply hasn’t changed, then I think the link following has information about what the problem is on your compressor.
https://fix-my-compressor.com/is-the-compressor-start-capacitor-working/
Looking for new pistin ring, head o-ring gasket set needed for model: 67847
2.5 hp, 21 Gallon, 125 psi, upright oiled compressor.
Any help on part numbers or where to find parts. Thank You!
I can find no sources for parts for a central pneumatic 67847. I hope someone else can help, though I expect their will be few available. All you may be able to do is measure the various components and try to find them from the manufacturers such as O rings, piston rings etc. The compressor companies rarely make these items themselves.
Hi I have a HF 62551 (many model number are the same) compressor 6 gal, 1.5hp . I need regulator parts or a regulator. Is it available or can you recommend a generic I can get a few parts out of. Parts and orings just under the knob. Thanks
Cannot find a photo of the unit. Please add a comment with a photo of the compressor, and a closeup of the installation where the regulator attaches. Thanks.
I have a 3 gallon pancake compressor and pulled a Griswold. I stepped on the manifold coking to the tool side of the regulator and the manifold is broken in two places. Any suggestions for where I can purchase a new manifold that would fit? Compressor, gauges and regulator all work great. Thanks
Steven, I don’t know what you mean by “manifold coking”. I suspect you meant cover? Regardless, there are no after-market parts for the 3 gallon pancake compressor that I’ve found, however, the ones I did find all are more than $30 plus shipping. Since a new 3 gallon Central Pneumatic is $60, if this size provides enough air, if it were me I’d buy a new one and keep the old one for parts which, I expect, will be needed sooner than later. Good luck.
Sorry – that was a typo. I meant to say “stepped on the manifold on the tool side…”. I’m going to be taking the manifold to a couple of shops and see if they have any suggestions as I have found nothing online. I will post an update if I have anything worth sharing.
Just bought a 21 gallon compressor and was wondering if there was supposed to be metal stuff in oil breather
Oil breather? Are you talking about the air intake to the pump? Please clarify. Also, what model is it? Thanks.
I have a CP 21 gal 125psi vertical A/C! It will not build pressure above 25psi & the Start valve is continuously leaking! Is there a way I can repair it or must I purchase a new start valve! I live in South Louisiana!
By the start valve, are you perhaps referring to what I would call the pressure switch? If so, when the compressor is running no air should be exiting the unloader valve that is part of this pressure switch. I can’t see if the unloader is on the side of the pressure switch or underneath and integral to the switch. From what you’ve written it seems that the unloader valve is not shutting off when the compressor starts to pump air, as it is supposed to. You may have a problem with the unloader then. See the pages about various compressor parts on this site if you aren’t sure of what I write.
CENTRAL PNEUMATIC 6 Gallon 1.5 HP 150 PSI “Pancake” Air Compressor regulator (red knob on top) is broke. I need replacement.
Where in the world can you find one? Searched the web. Going to visit my HF in the morning. Thanks!
April 19, 2020
I have leak from the regulator knob – I’m thinking I need a new one or maybe there’s an o-ring in there? Did you find parts?
I expect you’ll find that HF will not be able to help, not really having much of a supply chain for the many different models of air compressors they sell. I also expect that the regulator is part of a manifold, and that you’ll not be able to get parts… I may be wrong.
Here’s a link to the page about your compressor. On it you’ll find links to the manuals of the two model numbers that fall under these specs. Have a look at the manual for your compressor and scroll down to the parts drawing and list to see what I mean.
I have the 8 gallon Central Pneumatic model 40400, I have an issue where the shut off switch won’t stay up by itself in order to shut it off while running. I have to keep it held up while I pull the plug. It will stay up when the compressor is not running. I’m guessing I need to just replace the switch, Anything else I should check before doing that?
Are you saying that the manual shut off isn’t working? The ON/OFF switch should be on all the time the compressor is running, and the pressure switch is what shuts it off and cuts it back on when the pressure drops. If the ON/OFF part of the switch won’t shut off, yup, it’s time for a new switch. As to anything else, are there any other symptoms on the compressor that you feel aren’t right?
Yes, the manual shut-off. As far as I can tell, it is the only power switch. Thanks for your help. I’l replace the switch. .
CP 2.5hp 21gal, After good service for 3 years, the 1/4″ cold start valve failed to close after running the normal time. I ordered another cold start valve and installed it and it also bypasses continuously without closing. Am I missing something obvious?
Was the compressor still able to pump up to cut off pressure even though air was leaking?
Willy, it never got above 40psi. Is my problem related to volume issue. Maybe a reed valve leaking back to intake? I thought about installing a 1/4″ valve in place of the start valve and close it after the compressor got it’s stroke rate going and see what the pressure built up to. If it don’t’ build pressure I’ll pull the head and check the reeds. Any different ideas Willy? I’m retired oilfield but, surprisingly, I didn’t reach for the four pound hammer first
I think, rather than a cold start valve, that you have a pump valve failing and it’s not able to generate enough to close the cold start, providing that the replacement cold start has the same closing pressure as the original.
If you haven’t tossed out the old cold start, a good rinsing in solvent might help, but that won’t stop the issue if it’s not the cold start and a pump valve or gasket issue.
Also, if you have a plug for the cold start port, plug it. Empty the tank, that will emulate the venting over the piston, and start the compressor. If it doesn’t build to cut out pressure, it’s not the start valve.
I have a used Central Pneumatic “67708” air compressor and last summer the Oil Breather Plug just shot out. I contacted Harbor Freight and they don’t sell them. So my questions is will these fit my air compressor?
John, I don’t have the compressor in front of me to measure the threads on the oil dipstick tube. 16 mm is just under 3/8″. Is that what the hole size is in the oil fill tube?
Hi, Not sure where my first post went.
I measured the opening yesterday and it measured 5/8 of an inch. I also used a 5/8 tap just to check the threads, and it wasn’t tight but it threaded in. I’m attaching a picture of measuring.
Thanks for the photo, John. So, you know the port is approximately 5/8″, but it’s loose. That suggests that the thread is metric to me. What’s the size of the thread on the plugs you found?
Male Thread Diameter: 16mm/0.6″; Total Size: 56 x 28mm/2.2″ x 1.1″(L*Max.D)
5/8 is .625 so it might work.
Thank you. Ill let you know if they work.
I have a 21 gal Central Pneumatic compressor… Works great — fills up to 105psi and as soon as it hits that number, it shuts off and starts bleeding air from the pressure valve. When down to 50psi or so it starts up again. Back up to 105psi, shuts off and bleeds very rapidly down to 50psi and starts running again. I just replaced the pressure valve with a like one — seems to be doing the same thing. Ideas?
Allen, it sounds very much like your tank check valve, the valve that is supposed to keep the air in the tank and ready for use, is leaking, allowing tank air to flow up and out the unloader. Dump all the air with the power cord out, remove the fitting where the line from the pump enters the tank, and clean and test the tank check valve.
Thanks — I’ll give it a try…
Item #67696 Won’t hold air pressure at all wont stop running.
Sure Charles. A good place to start? Right here: http://fix-my-compressor.com/air-compressor-will-not-stop/
As well, other issues that maybe in play can be found here: http://fix-my-compressor.com/air-compressor-problems-and-fixes/
Please have a look, and then, add a comment to this thread if you still need some help.
I have the Central Pneumatic #62511 6 gallon oilless air compressor that pumps up to nearly 150 psi but does not stop. I attempted to remove the top, but none of the sockets I have will remove the m6x25 screws (I have tried all metric and sae sizes that will fit down the hole. It looks to me like the screws have a round head rather than a hex head which makes no sense, except if this is a way to keep owners from servicing their unit. The compressor is about a year old, and has about 5 hours of use on it. Any information on this will be welcome.
My Harbor Freight air compressor has only about five hours on it, and it will not pump more than 50 PSI. Used to work fine.
Model 62803, 21 gallon, 2.5 HP motor. Can you advise?
Sure. The answer depends on what happens when the compressor gets to the 50 PSI. Does it stop? Does it keep running? Please advise, and please also look at this page for more information.
keeps running.
Okay, if the pressure stays at 50 PSIish, and doesn’t rise, and the compressor keeps running, it’s typically a leak (tank drain, unloader valve, open line) or the pump has an issue with air sealing. A gasket or seal in the pump head, or a valve that isn’t working right. Solutions are found on either the troubleshooting or brand-specific pages on this site.
My 6 gal 1.5 GO will not start its approx 8 months old barely used shot approx 400 3 in nails that’s it.
I have a central pneumatic 8 gallon air compressor, model 94355 and need a pressure regulator. Can’t find one anywhere. The adjusting knob is stripped.
Keith, I am unable to find a reliable image of this 94355. Please add a comment with a photo of the whole compressor, and a photo of the regulator you are trying to replace. If the regulator is in a manifold, please remove the cover before taking the photo.
Here are photos with the regulator in and out. Thanks
Yeah, I was afraid of that. There are no after market sources for the regulator manifold. Your only choice I can see is to build one using off the shelf brass fittings, one that works the same but doesn’t have to look the same, and that may mean cutting out a piece of the cover to allow your jury rigged manifold to fit.
I got a central pneumatic 125 psi 21 gal 2.5hp air compressor keeps running not building air what could be the problem
Could be a bunch of things, Dillon. Hard to be specific in this response when the troubleshooting page on this site has a link to a page that is all about just this issue. Maybe have a look at that, and then add a comment here if you still require help. Thanks.
My central pneumatic compressor 2.5hp. 21 gallon squires oil through the fill cap?? What can it be??
Follow the link to the general troubleshooting page, and then scroll down to the page that addresses this issue. If you still need help after, please add a comment.
I have a 30 gal 150 psi vertical compressor that won’t pump up more than 50 lbs. No leaks. Where can i buy parts to rebuild the motor? Compression rings and oil rings and gaskets.
Not a lot of Harbor Freight air compressors have parts supply, Glynn.
You can search using the model number. Without that it will be hard.
You can make valve plates and gaskets yourself, and pages about that can be found on this site. As to the motor, any electric motor repair shop should be able to help. Unfortunately, getting professionals involved with rebuilding lower cost compressor components can quickly add up to more money that buying a new compressor off the bat.
I could not find a model number on this unit but did find a parts diagram blow up naming all the parts. I can rebuild it myself, i rebuild engines myself. Already bought a big 80 gal compressor but wanted to fix this one and give it go my son in law who doesn’t have one. The parts manual had a model number that closely match the piston housing on mine. It said that i could not buy parts but must buy the motor as a unit. In that case, it would be cheaper to just buy a new unit. I like my son in law, but not that much.
:-}
Can the Central Pneumatic 3 gallon 1/3 HP 100 PSI Oil-Free Pancake compressor be modified to have an intake feed rather than pulling from the ambient air around the motor, without having to drill and tap the cylinder head for a check valve and somehow disabling the intake through the piston?
If the intake of the piston is on the top of the piston cap, and it is not presently threaded, then no, I don’t see how.
If you can plumb the air to the intake port and the supply line is bigger than the intake port of the compressor, it should work. It would also depend on how long the supply line was and how many fittings in it, as that would reduce air flow.
I have a central pneumatic 3 gal 100 psi. It wont cut off after reaching pressure.
Likely the pressure switch is the issue, Bob. Please see this page for links to how to check.
Hi, I have a central Pneumatic 1/3 hp 3 gallon pancake compressor, it won’t work at all. My husband used it for some trim and now it’s completely dead. Tried the reset switch and got nothing. Is all hope lost? Thank you
Sure. Please see: https://fix-my-compressor.com/air-compressor-will-not-start/ and do the checks. Add a comment to the thread if you still need help after.
I have a Central Pneumatic model # 61454
The problem I am having is it shuts off at about 40 lbs and it won’t come bass look on unless I hit the reset button. Anyone else had this problem?
Lots of folks have the same sort of issue with their air compressors, Buck. Have a look at this page and scroll down to those that are part of the diagnosis and correction: https://fix-my-compressor.com/air-compressor-problems-and-fixes/
Please add a comment to your post if you still need compressor help.
I was having this problem too, my motor was drawing too many amps and overheating. This was due to having a 5HP SPL motor which is actually only 3.5hp with a 15amp full load. I purchased a new motor that is 6.5hp continuous at 23amps and have no problems at all. Check your motors amp draw at full load right before the thermal overload switch trips.
Brand new 1/3hp 3gal burns up fuse as soon as it is turned on. What amp fuse do I need?
If it is a Central Pneumatic 69269 compressor, it’s a 3 amp fuse.
father has a CentralPneumatic 2.5 HP, 21 gallon, 125 PSI cast iron vertical air compressor model 67847 that will not start. Can I get some ideas on what to troubleshoot that could be the problem for this compressor. My dad does have the original manual and I called the customer service number but they were not very helpful. Tried taking to a repair shop and were informed they do not work on Harbor Freight compressors
Check the capacitor on the motor, just replaced mine.
Sure. See the links from this page: https://fix-my-compressor.com/air-compressor-problems-and-fixes/
Hi,
I have a 3gal oiless 100psi pancake compressor Model # 61615. it was filling today and then suddenly I heard a big change in the noise it was making to fill. I then noticed it would not fill at all. I took apart and discovered the aluminum line that goes from motor/pressure head is broken. Any chance in finding a new one?
Hi David. I got a chuckle out of seeing the Q.C. (quality control) label beside the broken part. Take the fitting off both ends and go to a decent plumbing shop. They should be able to make one for you out of soft copper tube, which will work just fine. Or, get the fittings and tube and make your own using soft copper.
I have the average 10gal 2.5 hp air compressor on wheels pushes like 4cfm. I would like info on how or if possible to install proper compressor to get like 7.5+cfm I see motors and compressor for under 200 total but no info on if it will fit my style
John if you are looking for a compressor that delivers 7.5 CFM at 90 PSI, then you’ll want to get a compressor that’s a “real” 3 HP or so. Otherwise, you’ll stand the risk of buying a compressor that promises higher flow, but cannot deliver. On average, a smaller air compressor will deliver about 3-4 CFM of air at 90 PSI per each “real”, that’s run HP, not start HP, of compressor.
I purchased the 1.5 HP, 6 GAL. 150 Max. PSI. compressor. I used this about 4 times. The 5th time, I noticed that the compressor ran for a longer time than normal.
I went to inspect, found that the pressure gauges both showed less than 10 psi. I could feel the air being by-passed out the relief valve.
So I took off the top and checked the fasteners for the head. WOW, found two of them stripped. CHEAP FASTENERS FOR A $100.00 plus compressor.
Will never buy another central pneumatic item!!! I will go to Home Depot and get some higher grade fasteners. Thanks Central Pneumatic.
My start valve on my 125 psi harbor freight compressor wasn’t popping out. I replaced it. Still didn’t work. After checking things I found on the internet about it, plus taking the head off and checking reed valves, it still wouldn’t work.. I removed the air filter and the start valve popped out and started filling with air.
I replaced the whole filter unit.. Works great!
I have model #69667 I need replacement part 49 drain valve broken ?
If you are speaking of the tank drain valve, if you browse for “replacement tank drain valve” you will find many. It doesn’t have to be one from the compressor manufacturer.
Anybody know where I can get the three-eared Inlet valve reed for a Central Pneumatic 26 gal air compressor?? (item #69669, part #6 in the PDF owner’s manual) Thank you in advance
I have a older central neumatic air compressor model 61693 21 gal 2.5 hp I need a connecting rod where can I get one
I know of no after-market sources. You could try HF customer service at: 1 (800) 444-3353 during business hours. Otherwise, I hope someone else knows a source.
I have a central pneumatic model 61454. It is a couple of years old. About 2 weeks ago, I noticed that it would not pressurize past 75 psi.. It then dropped to max of 50 psi a week later, and now it won’t go past 25 psi. Any suggestions?
(It’s the) head gasket. You can make one, takes a little time to do.
Ended up being a broken Reed valve. Got a pair of Amazon for $12.50. Pressurized to 125, no prob. Bonus: did not need to break a gasket, it was located on the same level as the metal gasket.
Sure Jason. There are a few things to check. Info about what they are is located here, under Pressure & Flow problems:
https://fix-my-compressor.com/air-compressor-problems-and-fixes/
Please have a look, and add a comment with what you found.
I have a central pneumatic compressor model 69667. Do these compressors have a serial number on them or is it just the model number?
Hello Brittany. You’ve scrutinized all over the compressor, and under the cover? Given that these are manufactured in Asia, and there possibly isn’t a need for an individual serial number for each unit, odds are good there isn’t one. However, the proof can be found by calling: Harbor Freight at 1-800-444-3353 during normal business hours.
I have 21 gallon compressor. Does not build up pressure into tank. Pressure directly out of crankcase. What do you think problem can be???
It sounds just like what I had happen with my 2.5hp 21 gallon compressor. Check the Reed valves.
I found my parts on ebay
Central Pneumatic Air Compressor Reed Valve Valves STAINLESS STEEL 61693 61454
It would be helpful if you could explain this… “Pressure directly out of crankcase. ” more fully, Mark. And also in your comment on this thread, whats the model number of the compressor please?
My father purchased brand new from Harbor Freight item 69269 a 3 gallon 1/3 HP Central Pneumatic oiless air compressor in August 2017. He has used it maybe a half dozen times in 2 years. 2 weeks ago it was used to put air in golf cart tires and it worked fine. 3 days ago turned it on and it will not build air pressure. Neither air gauge (tank or outlet) is registering any pressure. If I pull the relief valve there is air pressure. Also air is released when the drain valve is opened. There is no pressure using the air hose and attachment.
Is this fixable?
Sure, anything’s fixable, even if parts have to be fabricated. The symptoms you describe suggest that there’s an issue with the pump, perhaps a valve, or, you’ve a major leak that drains the air as the compressor is pumping… like a tank drain open or some such.
Unless you get giggles out of working on stuff and fixing things, given that this compressor is currently selling new for $60, make a choice. Junk it, keep if for parts, and buy a new one that will, surely, wear out and need repair.
At $60 retail this compressor probably cost $10 at the Asian source or thereabouts, and as such won’t have much in the way of long lasting, quality parts.
Good luck.
My 2.5 gallon, unused but 2 years old, builds pressure to 100 psi but will only give a short weak burst of air through my air gun. Tried other tools with same weak response.
Well, I snooped around this site a bit after posting and found exactly what my problem is. The connecters on my air hose and the compressor are not compatible. I borrowed an outlet connecter from my large compressor and just like that the problem is solved.
OK, not the regulator! 🙂 Glad you found the problem.
When the air tool gets that “weak burst of air”, is the tank gauge pressure level showing a significant drop… by 20-30 PSI or more? If not, then I would suspect that you’ve got a failed regulator, Larry.
I have a central Pneumatic oil less airbrush compressor model 60329.
I am in need of a pressure switch and I called for a replacement and was told they do not make replacement parts for this compressor. Does anyone know of a compatible pressure switch for this model?
Thank you
You have pulled the existing pressure switch, Brian? If you browse for small compressor pressure switches, do you find any? Can you add a photo of the compressor and pressure switch in a comment on this thread, please?
Yes, i did pull the existing switch. i just purchased a low pressure switch (15 to 35 psi). I will try this when it comes in and post the results.
Thank you.
Thank you since I already have the gauges and I just would put together a manifold would I just need the regulator without the gauge.
When you buy a regulator it almost always comes with a gauge. Since they are low cost and prone to failure too, keep it as a spare.
Thank you for your information, I have 60730 and the cast manifold cracked, of course not wanting to add to landfill what parts could you direct me to to make my own manifold. I am sure I can get the brass fittings and I have the gauges, just the regulator piece to control pressure would have to be added can you assist me on finding the right one?
Use your browser to search for 1/8″ regulator, and you will find many. Or, visit a decent hardware shop that sells compressor parts like gauges, filters and regulators, and ask for a small 1/8″ regulator. That should do it. Like the one shown below:
3gallon model 60637 plugged in one time blew fuse and plug a gfi socket , and now cant find fuse, why is this happening , bad batch or what
If it’s new you have the manual. Can you check to see if it refers to the amperage of the socket into which the compressor is plugged? A blown fuse on the compressor could be related to that. If the GFI is opening to stop power flow, that’s suggesting that there is a much larger flow of electricity to ground on the compressor, and that suggests an electrical short.
If the amperage of the plug is within limits, yes, I’d think I’ve got a dud, and I would return it for replacement since it’s new.
Hi I have central pneumatic 2.5hp 21gal model 62803 and need help finding the uploader tube number 55 in the manual. I’ve been to several places that sell compressor parts and was told that harbor freight does not share information about their products. I also checked with a couple of harbor freight to see if can get a part number or someone point me in the right direction and no one could.
Anthony, if that’s the tube from the tank check valve to the unloader, yeah, they are a problem getting. A couple of things you can do. One is to visit a good plumbing shop and they often can provide 1/4″ copper tube with fittings that suit the compressor. You may need to bring the old with you to be sure they get the right fittings. You can do this yourself, but copper tube is a son-of-a-gun to bend without a bending tool, and it kinks really quickly. Or, visit a high end industrial distributor and get from the instant fittings to suit, and a length of high-heat urethane tube. Easy to install, and since this line rarely sees heat from the compressor, it can handle the unloading process nicely. I have one compressor on which I did this, had the same problem as you getting a new tube, and have never had an issue with the polyurethane.
Would 1/4″ OD nickel-copper brake-line work? Bends by hand without kinking.
If you are speaking of an unloader tube, that would work fine.
Hi.
I have a 2 hp 4 gallon (60567) compressor from Central Pneumatic.
Motor was stopping at lower and lower pressure and would restart itself again sometimes after 2 minutes on 0 bar. No breaker would jump or anything else.
Sometimes it would pump to 6 bar, sometimes to 2,5.
Expected Pressure switch failure, replaced with new one.
No difference yet. Seems the pressure switch works and gives power to the motor.
Breaker switch does not jump, no reset needed but the motor just has a mind of his own.
What to do?
Sounds like it is a power problem, Jarno. And that means a change in the power supply to the compressor, a capacitor may be failing, or mechanical issue with valves or the pump itself. Have a look at this page and read the pages that affect compressor pumping etc., and then add a comment if you still have questions.
https://fix-my-compressor.com/air-compressor-problems-and-fixes/
Thanks, It probably is something in the motor/power. After several hours and spending 70US on a pressure switch I have donated it to somebody with more patience. Bought a new one. Thank you!
Cannot find oil plug replacement nor the size. Need assistance in replacing the plug.
Model number of compressor, please?
2.64 gallon 47413 central Pneumatic
There are none that I can find on the internet. If you have not, please call Harbor Freight customer service at 1-800-444-3353, give them your compressor part number, and ask for the number for the dipstick. Also, what the dimensions are, both thread and lengthy. They may actually have one.
With that info you can google replacement compressor dip sticks and you will find a bunch. See if any of them fits, since the people that make the HF compressors also private brand many other compressor types, and many parts are interchangeable.
If not, visit your local hardware store, pick up a 1/4″ plastic male fitting of any type, and see if that’s the thread. Other threads on the compressor are NPT so with luck, this one is too. If it fits, put a small hole through it to allow air to vent, and you now have a plug. If you get the length from HF, you can use anything of that length to check the oil level.
I’ve tried multiple times, they cannot help nor can they provide the size or thread pitch. 1/2 inch will not fit as it is too big only slightly.
Hi Stephan. Sorry that HF didn’t help, though that doesn’t surprise me. Long on selling cheapest quality goods they can make, very short on after market support.
OK, you say the 1/2″ is slightly too big, yes? Did you know that the nominal OD is 0.533 for a 1/4″ NPT? So a 1/4 NPT is actually quite a bit bigger than 1/4″ and a 1/2″ NPT is .675″.
What was the actual NPT size of the fitting you tried? Was it 1/2″ or 1/4″ NPT? And, if it was an NPT, try the same size in a metric fitting will you?
I have a 21 Gal 2.5 HP 125 PSI compressor (model 61454) I bought about 5 years ago. I need to get a replacement Cylinder Gasket (part 16 from the manual). Any idea where I can get one?
Doesn’t seem to be any source that I can find either, Lee. I expect though that if you purchased some “high heat” gasket material from an automotive parts dealer, you could make your own.
I just purchased the 61454 CentralPneumtic compressor today from Harbor Freight. I followed al of the instructions making sure that oil level was proper. Initially the compressor would not start at all. After a few more attempts it would run for about 15 to 20 seconds then trip a breaker. I guess there is no factory acceptance testing done on these all. I will be taking this back tomorrow for refund and Not a replacement. I am very, very disappointed by the lack of acceptance testing is a thing of the past of I guess for this product as well as about everything else.
I just bought a 21 gal 125psi upright central Pneumatic compressor at a Harbor Freight parking lot sale. It runs fine but wouldn’t build pressure over 40 psi. I checked the reed valves and one was broken. I order a new set and in the process of fixing it I broke the exhaust tube. Any idea where one could be bought from? Would it be worth it to try to fix it or just carry it back, I still have a couple of days to bring it back. I got it real cheap and I’m kinda thinking to just try to fix it. I will use it for air tools but not very often, just to work on my own cars some.
Don’t know what you mean by the exhaust tube Sonny. However, based on your experience so far, if this were mine, it would go right back to the store and exchange or get a refund.
Hello i have a 2.5 hp 10 gal 125 psi central Pneumatic compressor , when i run it it runs for a minute then kicks off , even with valve open , i bypassed the reset and it ran fine and filked up to 125 psi , i then shut it off worried it woukd blow up lol Could i just need a new reset button ? Thanks Geneo
While it is possible the reset is the problem, the more likelihood is that the motor is overheating. What causes this? A too great load from the pump to the motor, like the pump is mechanically damaged and can’t cycle properly. Or, a pump head valve has failed, preventing proper air flow, and the motor is now running too long as a result and overheats, or, the motor start / run capacitor is failing and cannot any longer support the motor… or, you are using the compressor too long at one time and it’s overheating.
Based on what you’ve written you can likely ignore the last, and my guess would be a capacitor issue. If you see the page on general troubleshooting or air components, you will find info on how to check them.
I have 2.5 hp 21gal stand up pressure switch needs replacement, where to get one?
Go to this page and scroll down to the pages about the pressure switch. You’ll find your answer there, I suspect. If not, add a photo of the failed pressure switch as a comment to this thread, please.
https://fix-my-compressor.com/air-compressor-problems-and-fixes/
thank you for offering a place to post. I am finding that the valve that controls releasing pressure from the tank to the tool is not opening. Nothing changes, tho, unpredicably it worked for about 10 mins today…Any suggested fixes for that?
Not knowing the model of Central Pneumatic air compressor you have makes recommending a replacement impossible. If your question is about what I would call the pressure regulator, and if turning the knob does not change the pressure setting on the regulator gauge, and if the tank pressure is higher than the regulator setting, and pushing or pulling on the knob of the regulator does not reengage it, then it would be time to replace the regulator I would think.
So I usually have to empty all the air out of the compressor before it will start and if it’s cold it is even worse I have the 2.5 21 gallon upright I was wondering if this ‘t’ fix would help if so pictures would be nice 😉
Scott, please visit this page and scroll down to the section about compressors that won’t start.
Emptying the air before starting suggests an unloader issue.
When you say ” I was wondering if this ‘t’ fix would help if so pictures would be nice” I’m sorry, I have no idea what you are talking about. Please clarify.
sorry I thought I was replying to the post about how the guy put a t in and two of the pressure valves because his wouldnt get going
I have a central pneumatic air compressor model# 67847 2.5hp 21GAL 125maximum psi and it keeps shutting off right at start off I plug it in hit the on button runs for like 3sec and shuts off
Luis, now old, well used, using an extension cord?
I have the same one as Noel and every time we turn it on it’ll be on for a few seconds then the reset button pops out and it turns off.
That’s typically an overheating issue, and the overheating can be caused by a number of things, including power supply. Please look at the troubleshooting page, scroll down to the pages that address this issue, and then add a comment here with more questions if you still have them. Thanks.
I have a 21gal stand up or the central pneumatic and all of a sudden it stopped building pressure. I used it Thursday just fine started today and it wont build pressure. Help
Noel, are you saying that it stops running, or that it’s running and not building pressure, please?
Sorry i should have bee more clear. It will run but wont build any pressure past 30. Once it gets to 30 it will continue to run but no more pressure will build. the picture is where the gauge will stop but the compressor will continue to run.
That helps, Noel. That compressor symptom suggests a couple of things. If the gasket in the pump is failing, it may leak badly at 30 PSI and the air doesn’t get driven into the tank, but instead goes back and forth inside the pump. Or, it could be a broken valve.
Have a look at this page, and scroll down to the pages that address this issue for more specific help. Okay?
Would this be the problem or should I dig deeper. I think it’s called a reed.
THis was the problem. Compressor back up and running. Thank you for your help Willyr
Glad to have been of help. Have a good one.
Thank you. I will look into this and hopefully it’s a quick fix
I’ve seen a lot of comments on the 21 gal Central Pneumatics air compressor with starting issues. I tried all the suggestions to get mine to start consistently – new cold start valve, new capacitor, checked the bypass valve. I cured mine by putting a tee in place of my cold start valve and then put 2 cold start valves into the tee. They still close at 2.5lbs of pressure but it takes a second longer to close allowing the motor to get up to speed. Working like a charm now . . .
where did you get the cold start valve?
Excellent tip, Paul. Thank you.
I have a 10gal 2.5hp central pneumatic air compressor the oil fill cap blew off where can I get another one
I just Googled “central pneumatic compressor oil fill tube cap” and found a bunch. Have a look if you haven’t already done so.
I have a Central Pneumatic air compressor #69669. Where can I get the three eared inlet valve reed?
Angie, please upload a photo of the inlet valve reed you are seeking. There are non-OEM reed valves available, but I don’t know which is yours.
Just wanted to give everyone an update on what ive recently done to my troublesome 21gal 2.5hp compressor. So after the 3rd reed broke on me I decided to trace the good reed i had left onto a piece of .012 feeler gauge. I shaped it to match almost exactly and put it back together. Only this time i drained the HF compressor oil and filled with Mobile 1 full synthetic 5w 20. Also loosened up that start valve right next to cylinder head so it was still snug but not tight. Drilled 3 more holes in air filter housing. Since doing this it no longer trips either house breaker or motor breaker on cold start or any start thereafter. Is actually a useful compressor now. Tripping breakers and breaking reeds was a constant issue before. Havent had either happen since. Thought Id throw that out there to help others because HF most likely will not. Good Luck.
I have a 69669 air compressor. I nedd a compositor for it where can I get one?
https://fix-my-compressor.com/finding-a-new-compressor-capacitor/
My central pneumatic compressor will run and build air but compressor won’t kick off. What is the problem?
Dan, if you are saying that your compressor tank pressure blows by the normal cut out, and then the PRV lets go to vent over-pressure, that’s typically an issue with the pressure switch failing and not responding to the tank pressure.
My compressor will build air but not kick off it keeps running.
Model number? What pressure does it build to, or, is it building pressure past the normal stopping point and blowing the PRV open, please Dan?
I have a model #47065 21 gal and the compressor wouldn’t build pressure. I took off pressure switch and took it apart and noticed that the rubber diaphragm has holes in it. Where do I find a replacement diaphragm.
I very much suspect that you won’t find a diaphragm unless you craft your own. I expect you’ll have to buy a new switch, and since the switch of the 47065 is the same one as used on many other makes and models of compressors, visit your compressor store, look at the new compressors, find one with the same switch, and see if they have that switch in stock.
I thought so. I found one on Amazon that is the same. Should be here on Saturday. Thanks.
can’t get the Red Knob on the pressure regulator to screw down to adjust out going air
pressure. anyone with suggestions?
If lifting or pushing down on the regulator knob does not allow turning the knob to adjust the pressure, I suspect a failed regulator and a replacement is in order.
That black “reset” button just sits flush in the housing it’s in. Doesn’t really push in at all. Zero pressure on guage, compressor never shuts off, just keeps goin. How can I address this?
The reset button likely won’t do anything unless the compressor motor has gone off on thermal cut out, if it’s the button I think it is.
The compressor never shuts off, and the gauge reads zero, if that’s the tank pressure gauge and not the regulator gauge, then the pump isn’t getting any air into the tank, or, you’ve got a major leak that’s bleeding air as fast as the pump can make it.
Please advise which, and, take a look at this page for the issues and page listed that cause a compressor to run and not build pressure, if that’s the problem: https://fix-my-compressor.com/air-compressor-problems-and-fixes/
I think Harbor Freight should exchange Model 62803 21gallon compressor for customers who got stuck with LEMON COMPRESSORS. Im sure they are engineered to last just outside the return policy window but if it gets even light use it will become apparent that it only looks like a functional compressor. I will not buy another big item from Harbor Freight until they show some interest in customer satisfaction.
True. It appears to have way too many failure characteristics.
I have a Central Pneumatic 21 Gallon 2.5 hp 125 PSI Compressor. Air pressure would not build over 20 PSI. Replaced reed valves and it came up to 120 PSI and cut off as normal. As I released air with blow gun as pressure dropped , the compressor wouldn’t kick back on. Completely drained tank and again tried on off switch and it would not come back on.
Are you getting power to the pressure switch? With the tank empty, is power getting to the motor. Those are the first checks, please do so and let us know.
Definitely have power to pressure switch. With empty tank, pressure comes up to 120 PSI and shuts off automatically. But when I release air down to approximately 70 PSI, motor tries to kick back in, but compressor stutters and trips reset button. Cleaned, checked, and slightly stretched cold start valve spring to hopefully allow easier start , but again with empty tank, started up fine with 120 PSI, released pressure, and got same results. Where do I go from here?
See the page on this site about checking the motor capacitor. If power is getting through the switch to the motor when the pressure drops, and the motor is struggling to start, it’s typically either the cold start / unloader valve or the capacitor. Unless, the motor itself has failed. Check the capacitor and let us know if you would.
I have the 2.5 horse with a 21 gallon tank, 125 psi. When go to turn on it runs for about 5 seconds then kicks the reset button on motor out. Started out intermittently now does it everytime no matter how much air pressure is built up. It was bought brand new 2 years ago. Any help is appreciated thanks
That typically signifies a power supply issue. Not using extension cord? If not, and the compressor is plugged into the same outlet where it worked fine before, then the next step is to check the motor capacitor. The how to do that is found in the troubleshooting pages on this site.
Thank you for the info. Yes plugged into same outlet as usual and no extension cord
the thread where the unloader tube connects to the check valve ( on the check valve) is stripped- any way to fix? or where can I get a replacement check valve?. This is the 2hp 8 gal model. Thanks
Hi Richard. Dump all the compressor tank air, power down of course, and then remove the tank check valve. Google “replacement compressor tank check valve” and you’ll find many. Pick the one that matches yours.
I was going to do that, but after seeing all the trouble people had matching the threads I just slathered the whole fitting with JB Weld.. Not very elegant I know.
As long as the repair holds, and the compressor works, who cares if it’s not elegant? Sometimes building a new manifold for a compressor is the only way around it when an OEM manifold cannot be found, and the end result will be ugly, but it will work. Good on you for making the repair, one way or another!
I am looking for a Central Pneumatic 62803 21 gal. 2.5HP 125 PSI Air Compressor uploader tube. Harbor Freight customer service states they do not carry the part.
Tom, do you mean “unloader tube”? If so, remove the existing tube and either replace it with high heat urethane tubing or take the original to a good plumbing shop and they can find the parts to make your own.
What should my tank pressure gauge read on my 17 gal, 150 psi CP air compressor model 68066 when fully charged? Don’t need a 10 paragraph response!
150 PSI.
Thx will. why do you suppose it only shows 24 psi. my regulator pressure guage shows 145 when fully charge & shuts off. but tank guage only shows 24.. maybe the reason for such poor performance. Suggestions to remedy?
Turn off the compressor and dump all the air from the tank. Remove and switch the gauges. Power up the compressor again. What happens to the pressure readings?
Wanna make sure I understand. By goggles U mean the sealed gauge lenses? can’t switch gauges they’re different threads.
So sorry. Typo. I meant “Remove and switch the gauges”, and yes, to determine of the one that is showing low pressure in the tank is actually working. If gauge is working, and the tank pressure only gets to 17 PSI and the compressor keeps running and can build pressure no higher – to the 150 PSI cut out pressure – then it’s likely a pump issue, maybe gasket, maybe valves, maybe the piston… need to be sure what the problem is, first. And the purpose of the comments is to document the compressor problem and resolution for all visitors to see, hence no phone calls.
Interesting. will do & see where ur going! don’t thimk its the gauge though. THX!
will get back to ya.
my 2.5 21 gal. 125psi will not start up if air is in tank..it drags then pops breaker. Help!
Please see the troubleshooting pages on this site (link from top left navigation bar) for a link to information about why this happens and what you can do about it. If after reviewing that and doing the checks if you still need help, please add a comment here.
The drain valve is seized up on a Model 67847
Can you not just replace the whole thing? Lot’s for sale on line.
Yeah. That’s probably the plan based the answers for others I found here.
I need an output regulator for my Central Pneumatic oil-less air compressor MN: 99780;: Max pressure; 155psi; air pressure out; 125 psi;air flow; 6scfm at 40psi; 4scfm at 90 psi; tank capacity;17 gal. motor; 4hp at 13,rpm.
Thanks
Hello Bill. The regulator on the 99780 is nothing more complex than a general purpose regulator you can acquire on line or at almost any good hardware or big box store that sells air compressors and equipment. Read the specs on the regulator you acquire with the same thread size (most are common) and you’ll see that almost any new one for $15 or so will do the job.
I have a Central Pneumatic Air Compressor MN:99780. It compresses the air to about 145psi the drops to 125psi as it should. The problem is that no air discharges from the tank which is full. I found no clogged lines and believe I need a new Out-put regulator. Harbor freight does not have spare parts for this compressor. What can I do?
Looking for an image of a Central Pneumatic air compressor MN:99780 unfortunately did not return any pics of this compressor, so I have no idea what the regulator looks like. However, this page may provide some guidance: https://fix-my-compressor.com/regulator-is-leaking/
If it does not, please add a photo of your current compressor regulator as a comment to this post.
Have a Central Pneumatic 2 HP 8 gal 125 psi model 67501 air compressor. motor just hums and trips reset button when there is pressure in the tank. Release pressure down to 20# , hit reset and it will pump up to normal pressure. Any ideas on the problem. It doesn’t have a start capacitor so that is out. Does the run capacitor have a dual purpose? Thanks for your help.
Some caps have dual purposes. Off hand though I’d guess that whatever unloading mechanism your Central Pneumatic 2 HP has, that isn’t working. By removing the air that essentially dumps air over the piston, emulating an unloader function, and allowing an easier restart.
If not using any extension cord or power bar at all, and with the compressor plugged right into a socket, if the problem persists, check, fix or replace the unloader next.
There is an easy way to solve this problem.
The motor is not turning over fast enough to build a magnetic field (Lack of power). No magnetic field equals a huge amp draw a lot of heat from the excess amperage and no useful work.
In order to make things easier for the motor to turn over and build the necessary magnetic field we need to relieve the compression in the cylinder head. A ball or gate valve will work fine. Connect the valve directly inline with the air feed to the compressor tank from the piston or to the cylinder head. Open the valve when starting the compressor. The compressor should fire right up to full speed. If not you have another issue. Close it once the compressor is running to divert air back to the tank and let it fill.
This might not be the best solution to your problem but is the solution I have used on “central pneumatic” air compressors with the same problem.
This is the diagram of the compressor. Sorry but I have no idea how to check out the unloader. The only reference to an unloader is #55 which is an unloader tube. Do I have to replace the pressure switch?
When the compressor reaches normal cut out pressure and the pressure switch toggles to off to stop the motor the unloader valves job is to open, and to drain any air trapped over the piston(s), helping the restart process when the compressor restarts. The unloader tube connects to the unloader valve.
Empty the compressor, close the drain and start it, and allow it to run up to cut out. When it stops, a burst of air should come out of the unloader valve. I guess, but cannot see from the drawing, if the unloader valve is on the side of your pressure switch, or inside of it.
Compressor oil not showing on gauge. Runs fine.
Assuming it’s oil lubed, and we don’t know that since we don’t know what model Central Pneumatic air compressor you have, there must be an oil measure. When you say oil not showing on gauge, what gauge are you referring to? Also, if it is oil lubed, and there is oil in the sump, then it will run, but possibly overheat a bit depending on how long it’s used in one go.
I have that same problem with a 2HP 21-Gal 125# vertical Central Pneumatic compressor. Oil level does not show in the sight gauge. Filling (with high quality compressor oil to replace shipping oil that self-drained during the shipping process) very slowly and carefully watching the sight gauge, I could never see anything in the sight gauge. I was concerned that it was over-filling, because it took nearly 30 OZ of new oil, and I was right because it finally rose to the level of the fill cap (threaded hole that the cap screws into). I will need to siphon out some of the new oil, but have no idea what a reasonable # of ounces might be, since there is no capacity notation and I doubt the sight glass is going to start working. Then I will have a continuing problem when I need to add oil. Too bad there is no dip stick to check the oil level.
You can remove oil by taking out the screw directly underneath the sight glass. On some models it takes a phillips screwdriver, on others it’s a #5 allen wrench. The sight glass is also threaded and can be removed, which could presumably also give you an opportunity to diagnose the issue further.
Darren — Thanks for that info. Very helpful!
Thanks for that, Darren.
my 2hp 8 gallon compressor only pumps to 40lb psi with reguator wide open
Dwayne, the regulator has nothing to do with the pressure the tank gets to. The regulator only lowers the downstream pressure to the air tool. It’s the pressure switch that controls the on/off of the compressor, and if the motor is running and the pressure only gets to 40 PSI, then the pressure switch is working.
The issue may be the pump itself, and if you visit the page about troubleshooting air compressors on this site, you’ll find links to pages that talk about what to do about that.