Compressor will not build up pressure.
by Carl
(Alabama)
I used the air compressor and it worked fine. I turned it off then my son wanted to use it for a minute so I turned it right back on, it worked for a few minutes then stopped building up pressure.
Bill answers...
Carl, welcome. Nice to hear from Alabama.
I need a bit more information before I can even suggest a solution.
You say that "it worked for a few minutes then stopped building up pressure". Does that mean that the compressor motor continued to run, but no pressure was built?
If the unit is running and there's no pressure being built, check to make sure that the tank drain valve is closed. When the compressor is running they are so noisy that you can't hear that there's air escaping.
If the tank drain is closed, then look for leaks elsewhere.
Of course, if the compressor doesn't start that's another issue, but I don't know if that's the case for yours.
Cheers,
Bill
Compressor won't build pressure...just runs.
by Scott Shambeau in care of mee material handling
I have a compressor that is not working proper after the first build up it uses that air the the second build up the compressor just constantly runs on and never builds up. The number given for warranty is no help at all the answer machine does not even mention warranty.
model # 1nnf6 serial # hu 11/07 01975
if someone could call me at 1-800-242-5452 ext 1216 it would be appreciated.
Bill answers...
Hey Scott, nice to hear from you. Thanks for writing in.
Sorry that the Speedaire number didn't work. I had not problem getting through to them when I called. Maybe something's change?
I've moved your question to the "Compressor Will Not Build Pressure" page. At the bottom of this page are a bunch of questions and answers to pretty much all of the issues that might affect your compressor when it won't build pressure.
Have a read of those. Meantime, if anyone can help Scott directly, he has included his phone number.
If, after reading all the responses, you still don't get an answer, please write back in telling me what checks you have made to try and pinpoint your compressor problem.
Cheers,
Bill
Sears air compressor problems increasing pressure.
by Jerry
(Minnesota)
I have a 6.5 hp, 60 gal. sears dry air compressor.
It pumps up to 60 psi and then continues to run until I shut it off.
I replaced the check valve and the pressure switch. I have checked for leaks and the relief valve is good. I opened the drain on the bottom and there is no water in the tank. I rebuilt the pump last year. Any ideas short of a sledge hammer?
Bill answers...
Hi Jerry.
Hmmmm! The sledgehammer option? That's one that will give you lots of satisfaction, but only for a very short time. And then you have to go get another compressor.
Seriously, if your air compressor can't build the pressure in your tank past 60 PSI, and the pressure stalls at that pressure level, then there's something in the compression process that's preventing it.
A bum check valve wouldn't necessarily do it, as if you think about it, the line between the compressor head and the tank entry check-valve is a mini-tank, and if the air couldn't flow through the check valve into the main tank, then the pressure would start to build up in the line.
After the rebuild the compressor worked well, getting the pressure up to the cut-out level?
That the motor continues to run when the pressure reaches the 60 PSI level, that it doesn't heat up and go off on thermal overload, tells me that your compressor motor is working OK.
So I'm going to have to say that it's something in the pump that's failing and preventing the air pressure to get past 60 PSI, and I'm wondering if it's the piston seals.
Just my thoughts. Hope someone else can chime in with other ideas for you.
Cheers,
Bill
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Compressor runs, doesn't generate any compressed air?
by Without Air
(Kentucky)
Hello. My compressor runs all the time now and doesn't achieve full pressure.
This started occurring after I drained the tank and replaced the oil. It doesn't appear/or feel like it's leaking anywhere but with the shroud off and the fan running, and noise, it's impossible to know where my trouble is.
I have a central/neumatic 120psi compressor with a 21 gal tank.(harbor freight}cheapo.
It was working before I drained and changed the oil. The level had always been fine.
It was extremely cold out then too. But now after it's warmed up in the garage, the pump still always runs and the pressure never gets over about 60 psi.
Where should I start? switch or piston? any advice is appreciated. Thanks.
P.S. I planned on changing the regulator assembly (upgrade) for better constant control.
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Stanley Bostitch 2.0 oil-free 6 gal. compressor doesn't build any pressure.
by Leeann
(Texas)
I am trying to figure out why my compressor is not building ANY pressure at all.
I was attempting to texturize a wall that I had just put up.
I managed to break the cable leading from the unit to my srayer tool.
I turned the machine off and cut and repaired the end of the cable.
There are no leaks in the cable.
I was able to make it as though the hole never broke, however, when I turned the compressor back on, it would not build any pressure.
I check to see if there was air coming out of anywhere that it shouldn't come out of, but everything looks fine!
I touched nothing but the output hose, when I was fixing it.
Please, if anyone has any ideas of what I should be checking for, it would be MUCH appreciated! This is my first time using the machine. My husband is in Iraq, so unfortunately, I have no one here to ask for help. I tried to search the site for an answer and couldn't find one, so I apologize if something like this has already been addressed.
Thank you SO much!!
Hey Leeann....
I need a bit more info from you.
By the cable, I expect you mean the air hose from the compressor to the spray apparatus.
Before you "broke the cable" was the compressor working properly? Did the compressor ever reach high pressure cutout and stop all by itself?
Were you actually doing some spraying?
There is no reason for your compressor to stop pumping air just because the cable / hose broke.
If the compressor was working before the hose failed, and assuming that when that happened the compressor didn't run for a long time without stopping, then you must have a huge air outlet somewhere.
Can you provide some more info please?
And, I'm sure curious as to how you did break or hole that hose.
Cheers,
Bill
Air compressor won't build air pressure.
by Vinnyv75
(Roanoke Tx. )
I have an ordinary air compressor, that is only 1/2 hp,rpm 1725,115v. My compressor turns on, but does not build any air. Whats wrong with it? Please, I want to know.
Bill answers...
Hi Vinnyv75, nice to hear from Texas.
Your problem could be as simple as a plugged air intake filter. Have you ever cleaned it? The compressor can't compress air if it can't suck any into the compression cylinder.
There's a bunch more questions and answers here about compressors that don't build pressure.
Have a read of these, and if that doesn't help, let me know.
Cheers,
Bill
When pressure gets to 40 psi it will not go up anymore.
by thelbert
(madisonville ky)
when it gets to 40 psi it will not go up anymore i can find pres vale.
Bill answers...
Howdy Thelbert:
Nice to hear from Kentucky.
Your question seems to be somewhat of a common problem.
Here's one question and answer.
Don also wrote into that question and added:
Hi,
I had the same problem. It was a bad /broken head gasket. If the air intake is hot that is a sign that the air is blowing back out the intake and the compressor will not reach pressure. It could also be bad valves. Start with checking temperature. The intake side of the head will remain cooler than the discharge side.
You also want to have a look at this post, and then wander around the four troubleshooting pages to see the questions and answers that fit within your problem.
Hope this helps.
Cheers,
Bill
Air compressor will not fill past 40 psi and still continues to run.
by ken
(vero beach, fl.)
I have a kobalt compressor. The compressor will only fill up around 40 psi. The supply line from the pump to the tank usually heats up. after it reaches the 40 or so psi. The line cools as if no air is being pumped from the pump. Is it my switch or the pump That is the problem? The switch is a condor model MDR21.
Bill answers...
Hey Ken, nice to hear from you.
I don't believe you have a switch problem. If you did, either the compressor wouldn't turn on at the low pressure cut-in, and when it reached the high pressure cut-out, it wouldn't turn off.
That your compressor is running and the air in the tank is not getting past 40 PSI tells me that it's a mechanical issue of some sort.
You are clever to pick up on the temperature of the line running from the compressor head to the tank. If the compressor was compressing air into the tank, as you point out, that line would get too hot to touch.
So why does your compressor stop compressing air, yet keep running?
My guess is that you've might have a piston / cylinder problem, and that once the air pressure in the tank gets to 40 PSI the back pressure is more powerful than the air that's trying to get into the tank, and the air stops flowing from the compressor head / pump as a result.
You might have piston seal problems, or then again, your electric motor might either be failing or the drive mechanism to the compressor head is slipping once there's enough load on the compressor workings.
Those are my thoughts.
Good luck.
Bill
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Won't get past 40 PSI, blows air out the intake.
by Eric
(Fort Worth, TX, USA)
My air compressor recently stopped pressurizing past 40 psi. I've noticed that when I first turn it on, it feels like its sucking air into the intake (as I'd expect) very strongly, but as it gets closer to 40 psi, if I block the intake with a finger, it alternates between sucking and blowing very quickly as though the valve isn't closing when the piston is trying to pressurize the air.
I've disassembled it, and all the piston rings appear to be intact, as do all the gaskets. The valve is just a small flap of metal that is held on loosely by a couple pins and is pushed down on the intake stroke by the incoming air, and on the pressure stroke it's pushed up against the head to close off the inlet path, forcing the air into the tank.
I'm at a loss, though, when it comes to figuring out what to do to get it to seal correctly, if it's even the problem. Is there anything else that would cause air to blow out the intake?
I've read all the other articles in this section but nothing really seems to apply, other than one comment that it might be bad valves. If it is bad valves, what do I do? is replacement the only option?
Thanks for any help!
-Eric
Bill answers...
Eric, first, thanks for writing in. I appreciate you visiting this website.
Second, you've done yeoman's work in trying to diagnose your compressor problem. And you've hit on almost everything that I can think of that might be cause the problem.
Three more things to check. Have you replaced the element in the intake filter ever? If you can't blow it clean, put a new filter in.
Next, what's the status of the check valve going into the tank. Is there any possibility that it's not working properly. You might want to check that.
Last, maybe the motor's just running out of poop? Could be that it just can't overcome the load once the pressure in the tank reaches that 40 PSI.
Anyone else?
Bill
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Compressor wont pump above 25 psi
by Randy Ferrante
(Willimantic,Ct.)
My compressor wont pump above 25 psi.It keeps running and running,i've checked the hose for leaks and there are none.
No air coming out of the oil filler.
I've even opened the valve to its max and it just wont go no higher.
It's a campbell hausfield 5 hp 30 gallon and is only about 3 years old and i dont use it all the time.
It worked one day and when i hent to use it again it wouldn't go past 25 psi.
Any ideas? Could it be the pressure regulator or what. Thank you and have a great day.
Randy
Bill answers...
Hey Randy, thanks for writing in, and howdy to all the others visitors from Connecticut.
There could be a number of things that have "gone south" on your compressor that cause it not to get above a certain pressure while still running.
Among other things it could be that the intake filter is plugged up with crud, the intake valve isn't working properly, the rings are gone on your piston (you do make sure you've got enough oil huh?), or your motor is running out of poop.
Tell you what. Have a look at all the questions and comments on this page.
I expect you'll find your answer there.
Cheers,
Bill
Craftsman Model # 921.166390 won't build pressure.
by Dana
(Michigan)
My compressor will run, but will not build up pressure past 20 psi. It is continually running. what could cause this to happen.
Bill answers...
Hi Dana, and welcome to all other Michiganites!
I've moved this posting to the page that deals with compressors that won't build pressure.
Please read the questions and answers as this topic has been pretty much well covered.
Cheers,
Bill
Compressor will not pump past 20psi
by Ben
(Port Orchard, WA, USA)
I recently bought a 60 gallon 6hp 125psi air compressor that worked but took forever to pump up to its max 125psi rating.
Once the compressor reached 125psi the pressure switched worked as it should and shut the motor off and tripped the unloader valve.
Since it was an older compressor I figured the entire pump could use a rebuild. I disassembled the pump and found the rings, rods, and valves were extremely worn so replaced all of them.
I reassembled the compressor and found that the compressor would only pump up to about 20psi when the pump would start to work really hard and the motor would start to bog down and the belt starts to chirp but does not completely slip. I figured it was the check valve so I replaced it but found that it didn't fix the problem.
I soap bubble tested all the outlet lines to the tank and the sealing surfaces around the pump (found no leaks). The inlet of the valve head is pulling in air.
I double checked the motor and it is receiving 240v.
When there is no load on the pump and the outlet valve on the tank is open the compressor is pumping out a sufficient amount of air. Its only when I close the outlet valve on the tank and put a load on the pump is when the compressor pump really starts to bog down.
Can you help?
Thanks,
Bill answers...
Hi Ben, thanks for the email and the thoughtful content.
I'm going to guess based on what you've told me that you've added load to the compressor pump assembly in some way, when you rebuilt it.
A motor can only put out so much torque and, if the load starts to exceed it's capacity, it will bog down, ultimately overheat, and go off on thermal overload or pop a breaker.
When the line is open, or "when there is no load on the pump and the outlet valve on the tank is open the compressor is pumping out a sufficient amount of air", doesn't say much except that the compressor runs well under a no-load condition. What is "sufficient amount of air"? It's higher flow, but a lower pressure is what it is.
If you are comfortable doing so (be real careful, 120 VAC can kill, 240 VAC will kill) put a multimeter on the supply line to the motor and watch the amperage as the compressor comes up to the 20 PSI range. I'll bet you're going to see a significant increase as the motor starts to labor to overcome the load as the back pressure in the tank increases.
That's my guess. Other views are welcome and will be published, if you have any. I am not an electrician, so my advice is always suspect. :-)
Cheers,
Bill
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why does air pressure only build up to 30 lbs
by John Haynes
(South fork, pa)
The air pressure always would build up to 110 lbs. now out of the blue, it will only build up to 30 lbs.
Bill answers...
Hey John, thanks for visiting and writing in.
Tell you what. Go to this page and have a read of the questions and answers as the bottom.
They are all about why compressors run and don't build pressure.
If you find, after you've read them all, that the answer isn't there, write back in and give us more information, OK?
Cheers,
Bill
