You have your air hose connected to the discharge coupler on your compressor but compressed air will not come out of the air hose. What’s up?
It is more than a little aggravating to have your air hose plugged into your air tool, you squeeze the trigger and… nothing.
There could be a number of reasons why compressed air will not come out of the air hose.
So, let’s tackle the reasons in a logical order – from tank to air tool – to help make your compressor diagnosis and problem resolution a little easier.
1st thing to check
In the photo above, the compressor tank gauge is shown at left, and the regulator air gauge is shown at right, attached to the compressor regulator.
Have a look at your compressor tank gauge. What is the pressure reading? If your air compressor has cut in, run up to cut out air pressure, then the gauge might read somewhere in the range of 100 -150 PSI, depending on the type of air compressor you have. If you have no pressure being displayed on the tank pressure gauge, then that is likely why compressed air will not come out of the air hose.
If there is no air pressure reading on the tank gauge, then start your air compressor and let it fill up the air tank. If your air compressor won’t start, that’s another problem to deal with, but for sure, that’s also why you are not getting compressed air out of your air hose!
2nd thing to check
The tank gauge displays the pressure of the compressed air available in the compressor tank. On most compressors the compressed air flow from the tank to the compressed air regulator is unimpeded, though it might flow through a manifold that holds the pressure switch, similar to the setup shown in the photo above.
Details about the regulator operation are shown on the regulator page. Simply though, have a look at the regulator gauge. It’s either marked as such on air compressors that are fully shrouded, or it is attached to the actual regulator, as is the one in the photo. Is this gauge showing pressure?
If it is not, the issue may only be that the regulator pressure setting has been turned down to zero, effectively shutting off the air flow. The resolution to why compressed air will not come out of the air hose may be as simple as turning the knob on the regulator (in the photo, it’s the orange knob on top of that regulator) in order to increase the pressure setting to the point where you have compressed air flowing through the regulator to the discharge coupler.
OK, is there a pressure setting on the regulator gauge? If not, dial it up to about 20 PSI below the typical cut out pressure of your air compressor. Problem solved? If not, let’s press on.
3rd thing to check
If we have air in the tank, and we have a pressure reading on the regulator gauge, it’s a good bet that you have compressed air flow to the regulator.
If the regulator has a pressure reading, that’s reading the downstream side of the regulator, and that should mean that air is flowing through the regulator to the discharge coupler on the compressor. If there is no air in the air hose, then the problem may be your air compressors discharge coupler.
In the photo above we see a typical, smaller air compressor, discharge coupler.
Inside the end of the discharge coupler, right at the back, there will be a ball or flap that is blocking the compressed air that is in the compressor tank and flowing out to the coupler from blowing out to atmosphere.
The discharge coupler is “checked” meaning it has a built in check system that will not allow compressed air to flow through it until the internal check valve is opened. Normally you would open the check valve inside a discharge coupler by inserting the mating connector.
Before we do that, I would like you to try this.
Preferably wearing a work glove, and using a small, preferably non-metallic object (a pencil comes to mind), and holding the object very tightly, I would like you to slowly insert the pencil or object into the discharge coupler until it reaches the center back of the coupler. If you wish to look inside the coupler with a flashlight to orient yourself, that would be good too.
If the object you have inserted is small enough to actually touch the internal check valve, and without looking into the coupler, and making sure that no one or breakable object is in line with the discharge coupler, gently push on the ball check.
Do you hear or feel an air flow? If the pressure regulator gauge shows a pressure reading, then air should be flowing to the discharge coupler, and you should have air bleeding out of the discharge coupler when you press on the ball check at the inside back end of the coupler.
If air is not flowing, either you are not pushing in on the ball check, or you have no compressed air at the coupler.
If you are certain that you are opening the ball check inside the discharge coupler, and no compressed air is flowing out of it around the object and your gloved hand, that strongly suggests that your air regulator is blocking air flow.
If the regulator pressure gauge is showing the 80-100 PSI you would have set it for, then either the pressure gauge itself is broken (unlikely if the gauge needle moves when you rotate the regulator knob) or somehow the regulator is blocking flow. That may mean it’s time for a new regulator.
But I am going to assume that when you depress the ball check inside the coupler, air blew out.
4th thing to check
OK, so far we have found that air is flowing from the compressor tank, through the regulator and to the discharge coupler. We have determined, by pressing on the ball check in the back-inside of the discharge coupler, that air will flow when that ball or flap is depressed.
The next test then is to be sure that the air hose connector you are plugging into that discharge coupler is actually doing its job, and as well as connecting your air hose to the compressor, it is actually letting air flow.
How? Well, when you plug an air hose into a coupler then you can usually tell that compressed air is filling the hose, as it responds to the influx of air pressure by flexing and moving. Is this happening when you plug the hose connector into the discharge coupler?
If you are not sure, then after you have plugged the air hose connector into the coupler, grab the coupler that is at the other end of the air hose, and do the poke check described above. The one to test he discharge coupler.
If you push on the ball or flap inside the coupler on the end of your air hose, and no air comes out, it’s one of two things. You either have a kink or blockage in the hose, or the hose connector you plugged into the discharge coupler on the compressor is the wrong one, and it is not opening the coupler to air flow. (See the page on couplers and connectors for more info on this).
5th thing to check
If you have air flowing out of the coupler on the end of the hose, and when you plug your air tool into that coupler, either the connector on your air tool is the wrong type to open the coupler on the air hose, or your air tool has a problem.
Hope this helps. Good luck,
If this does not resolve your problem about compressed air will not come out of the air hose, please leave a comment below.
Really appreciate this page. I have a Craftsman 135 lbs portable compressor. As the same of others, been a great unit since I purchased it 3 years ago until I went to use a brad nailer and nothing. I than attached a “sprayer” to blow off sawdust and very little pressure. I did check the connector at the source by depressing the valve and plenty of air came out, but it will not deliver the air at the end of the hose. All the connections being used are what came with the unit. Could the connector just be worn out?
If it’s the same connector as always used, then I wouldn’t think so. If you are referring to the coupler on the compressor into which you push the connector, then again, the coupler shouldn’t be worn out either. However, I wonder how much air you let out? Try this. Close the regulator all the way by turning the knob until the output reaches zero. Push on the check in the coupler again to void air between it and the regulator. Remove the coupler. Now, slowly open the regulator by dialing up the pressure. Monitor the outflow. Does it continue to flow, or does it slow down after a short while?
Or, with a glove and safety glasses on, with the regulator set for 90 PSI, use a wooden probe to push open the ball check in the coupler so air can flow freely, and monitor the air flow. What happens to the display on the regulator gauge? Does it blip down a bit and come back up, or does it go down to zero?
My gauges read no pressure but turn the valve on bottom of tank and air blows out.
Hello Jeffrey. Let’s start by telling us this. When you open the tank drain and air blows out, how long does that air last with the compressor turned off?
When you close the tank drain and start the compressor, does it sound normal?
What is the make and model, and how old is this compressor?
Thanks.
Thank you for this page. I’d been trying to diagnose my weak airflow for months, to no avail (tank compresses fine, compressed air flows to air regulator fine, seemingly – but air bursts for a second then fizzles to a weak, useless stream) Tried your troubleshooting steps and somehow the issue has been resolved. I got through ‘3rd thing to check’ and I now have strong air flow again. Thank you Willyr!!
Cheers and thanks for the Kudos, Doug.
I have Dewalt 15 Gal. D55168 compressor. Compressor fills tank fine and tank gauge operational.
However
Air regulator gauge shows no pressure which logic implies no air getting to coupler where I attach the hose.
is the regulator knob failed? Do I need a new manifold?
Hi Michael. I rather suspect that the regulator is pooched. If you remove it, and put the coupler back on without a regulator, do you get a full flow out when you insert an air line to an air tool?
Ok, I have a block hose. What can I do?
If finding the blocked spot, cutting the hose, and splicing it is difficult, then maybe buy a new hose?
Small amount of air coming from the air compressor
Make, model? New issue, was OK before? Any change on how it’s used, hose, etc?
Compressor pumps up great both gauges read good the only way to get air out is have a second person push the air line into the coupler and hold it so we got a new coupler and end to the air line and it does the same thing! It’s a 3gal Huskee brand portable compressor.
The coupler and air line connector you were using before buying a new one, were they original equipment, and did they work together properly at one time, in other words, did you have any issues with air flow using them before?
Can you adjust the output air pressure up and down by turning the dial on the regulator?
Please provide a bit more info if you will.
Yes sir I bought the compressor new 5yrs ago worked great til this summer and then nothing came out of it it did sit for 3mo. I did adjust the regulator to no avail I did insert a pick into coupler no air. Perhaps need a new regulator?
If the compressor runs and fills the tank to shut off still, that’s good.
If air doesn’t come out of the discharge coupler without someone pushing in on the coupler with the connector, that suggests that it’s a broken coupler, broken connector, or coupler/connector mismatch.
If it was the regulator, pushing in on the discharge coupler/connector shouldn’t affect the air flow.
However, since regulators are fairly cheap, in your shoes, I’d put on a new regulator to see.
I have an Ingersoll Rand Compressor model P1IU-A9. I have 2 issues. First is that white powder is coming out the discharge. It looks like white baby powder. What is this powder?
The second issue (not sure if the powder is causing it but don’t think so because it worked before with the powder) is that I am not getting any air to come out of discharge hose. There is air in the tank, it has pressure and the discharge gauge has pressure, but once I plug my quick connect hose to the unit, the discharge pressure guage goes to zero and no air comes out. Please help!
I have same powder in mine . Gauges both say 125psi, but i plug in hose and discharge gauge immediately reads 0 psi. I think the powder is some type of corrosion in the manifold and plugs up the regulator. I have a water drain on my tank and no powder comes out when i open it.
I have no idea what the powder is. Something ingested into the air intake, perhaps? As to the flow issue I suspect the regulator is shot. Remove it (tank empty) and plug the coupler into where the regulator was. When you plug in an air line, if you get air out of the line, then it’s a pretty good bet the regulator is the issue.
thanks for your reply. The powder is not something ingested into the intake, sure of that, I just use it in clean environment to air my tires. I think it may be paint from inside of tank. I haven’t done the regulator test yet, but I did stick a metal object in the discharge hole and pushed in the ball thing and air came out. but when I plug in my coupler on hose the regulator goes to 0 pressure and no air come out. frustrated. only had it 1 year.
If poking open the ball-check allows air to flow with volume, not just a low flow, but one that changes as the regulator pressure changes, then it’s either that the connector being inserted into the couple is not a match, there is a plug in the hose, or there is an issue with the coupler connector at the air tool end. Please see this page.
Hey willy, new development. Was checking it again today and brought the tank full of air at 125psi. The discharge gauge now is at 0 and when I press the ball check in no air comes out – does this mean I need to replace the regulator?
If turning the regulator knob in both directions does not alter the gauge on the regulator, and you cannot turn the gauge up to the pressure you want downstream, then from what you’ve written Mark, yes, I think that’s the issue.
i have very little air coming out to my tools
Thomas, not much information to go on… make and model of compressor, for example. I can say that often when this problem presents, it’s the regulator that’s interfering with the air flow. Again, can’t be sure as I don’t know what compressor you have, but typically regulators are under $20 and replacing yours might be the answer, assuming that this problem is new and the same hose, compressor and air tool worked before.
I have a kobalt air compressor and I can hear air leaking out of the connector that is plugged into the compressor but not the other end of the hose I tried the pencil test and air is not flowing out of it when I press it please respond back that will be much appreciated thanks
Just to be sure I have this right, you plug a connector into the discharge coupler on the compressor, and no air comes out. Then you push a pencil into the discharge coupler, depress the ball check or flap, and no air comes out? Is this new? In other words, has the connector worked with the compressor coupler before? If so, then I would suspect that the regulator is blocking air flow, as long as the tank pressure is higher than the regulator setting.
I’m very glad to have found this page but I’m still stumped. I have a 3 gallon pancake compressor and it has worked well for the past few years. This year, without me changing anything, air does not come out of the end I use to inflate. I did your trouble shoot, and there is air in the tank and air comes out of the valve using the pencil test. I can get it to work if I brace the compressor (like against my car tire) and shove the air hose in the discharge coupler and hold it there. Thinking of the pencil test, its almost like the male end of the coupling on the air hose has become too short to open the ball valve. Very strange.
So, you insert the connector on the hose into the coupler on the compressor, and insufficient air flows to fill a tire, but if you stick a pencil into the discharge coupler on the compressor, there is lots of air? Does the lots of air continue, or does it wane. The way I see it, you either have a blockage in the connector on the end of the air line (often caused by insects building nests) or the regulator may be failing and blocking the air flow.
Thanks so much for the reply. The hose is definitely not blocked, and there is tons of air for the pencil test. I was looking at the net some more after posting this and someone else mentioned that the same scenario was caused by an o-ring misfit in the regulator. I’ll try that next. This was a Harbor Freight compressor, so I guess I got what I paid for.
Thanks! This was super useful and I was able to get air flowing again
I have tried everything you suggested to get air out of the hose. Gauges showing 115 psi so why nothing coming out of the hose???
If you have tried everything, you would have to have taken a tee off from before the air regulator and installed a coupler there. If, when you plug the air line connector into that new coupler, air flows to the tool, then it’s likely a failed regulator that is causing the problem. If air doesn’t flow from the coupler installed before the regulator, then it’s likely that you have a connector to coupler mis-match and the ball check inside the coupler isn’t being opened when the connector is inserted.
I have a CH 80 gal 5 HP. When I use an air tool at first it has power then dies down.
Bobby, there are things to check that have been listed on the troubleshooting pages about compressors that have no air, or not enough air, coming out of the hose. Would you let me know what you have checked, please?
In 2007 I bought a Craftsman 921.166360 (125 PSI/1 HP/5 gallon) air compressor. Right out of the box, it sometimes would NOT put air into deflated tires or add air to some that were just a little low on pressure. However, on some other low tires, the compressor WOULD fill the tires. No clear pattern to this: sometimes air flows out of the chuck and sometimes nothing does when I fit the chuck to the valve stem. When I depress the pin in the chuck air always blows with normal force. I put a different chuck on the hose, but the compressor operated the same. I put the brand new compressor up for 9 years and forgot about it. I tried it again today, and the operated just the same. I did not note the tank or regulator pressures, but I’m assuming they are OK since I get forceful air downstream of the machine through the hose and to the chuck, just not from the chuck into the tire’s valve stem. Would appreciate your view.
Did you follow the steps suggested to help diagnose the issue? Are you certain that the connector on the air line that plugs into the discharge coupler on the compressor are a correct match? If not, you can get problems such as you describe. Yes, monitor the tank gauge and the regulator gauge to help determine what happens when you attempt to use air. Glad that the compressor worked at all after sitting unused for 9 years.
My problem is: Whiile 100 psi worth of compressed air is in the tanks. Both gauges work fine, though when I plug in the air hose to utilize this air, it bleeds the air pressure in the hose in a split second while the compressor is still fully compressed with air.
What is happening?
We suspect that your air regulator is the culprit, not allowing sufficient air to flow through itself quickly enough to keep the air line full. Not knowing the make and model of the air compressor makes it hard to offer specific advice. If yours is a smaller DIY type, a replacement regulator may not be too expensive, and replacing the existing one with a new one would be our suggestion.
That, or the connector you are inserting into the coupler is mismatched and it is not opening the ball check in the coupler sufficiently to allow enough air to flow to keep the line full.
I have 140 psi at the compressor 120psi at the regulator and I do have air coming out the hose end to my impact gun,, BUT its dosent have power ive tried 3 different guns still same no juice,, HELP PLEASE..
let me add from compresspr to front of garage is solid pipe, then I have the retractable 25 feet of soft hose that I connect tools too.
Ive blead the water , did an oil change and filter change and purchased a new gun ….
We think, unless something is in or on the air hose and impeding flow, that it is possible that the problem is the air regulator. When they start to go wonky, reducing flow to the air hose is one of the complaints. If you can Tee off the line from the tank before the regulator, and put another discharge coupler there, you will have full tank pressure flowing to the air tool. If that resolves the problem, then you can be pretty sure you need a new air regulator, or the one you have fixed, if parts are available. You do want to use regulated air if possible, as it’s best for the air tool and in reducing energy consumption to run the air tools at the lowest possible pressure at which they will do the job. Please let us know your findings, if you would.