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A number of folks have problems when their Campbell Hausfeld will not build pressure.
Here are a few of their questions and tips for their Campbell Hausfeld air compressors, to try and help folks with their specific problem.
Do you have your own issue with a Campbell Hausfeld that will not build pressure? Please add it at the end of this page.
Question: I have a cambell hausfeld wl6701 that will not build air pressure although every thing seems to be operating normally can you help?
Response: Your compressor cannot be operating normally if it isn’t building pressure now, can it?
Please shut of the compressor, drain the tank from the tank drain, shut tank drain, and restart.
Does it start properly now?
Let it run for a couple of minutes and monitor the tank gauge. Any change whatsoever from the zero reading it should have when you drained the tank?
If no pressure is built, shut the compressor off, and find the intake port. Start the compressor. Is air being pulled into this port as the compressor runs? You might have to remove the intake filter to check this.
Comment: about Harold’s WL661100AJ.
Yes, air is being sucked into the air intake.
Response to comment: Harold, as long as air is only being pulled in, and not huffing back out, then that suggests that your intake valve is good.
That leaves a pressure related gasket leak, or a high pressure valve to be checked. Those will required a tear down, I’m afraid.

A new Question: Just bought a used 5hp 20 gallon compressor (VS500602AJ) and it seems slow to fill. It takes about 4 minutes to go from empty to the cutoff at 125lbs.
I do get a little puffing at the intake which leads me to think that I’m losing some of the charge back out the intake.
The rear bearing on the motor is a little noisy also. What do you think?
Question: Ian, yup, that sounds a bit slow, but not too bad, considering the great deal you got… did you?
You will have to do some re & re on the intake valve, and I suspect the high pressure valve too. They may be part of the same plate.
If you can’t lube the bearing, then I suspect its not long for the world either. Yet, you can still use the compressor, and weigh what you would spend in time and money against the cost of rebuilding, and maybe just use it up?
Comment: by: Ian. Changed the oil in the pump a few minutes ago and it looked like creamy white gravy. Looks like this compressor might not have been such a good deal after all. Thanks Bill.
Response to comment: That might be the presence of water, a by product of compressing air, and indicative of piston seal leaking. Might be that’s all it needs.
But, are you getting air out? Is it doing work for you? Might have been a good deal after all, like my $10 air compressor I talk about on my videos page.
Comment: by: Ian. Yes, I get air out of it and it does ok, just slow to reach cutoff and slow to recover. I bought it primarily to provide air for a plasma cutter. I’m hesitant to put much money into it. A set of valves costs $41 and if the motor goes, that’s $130 at Harbor Fright. It’s also missing the intake filter that runs $9 plus shipping. That would put me at about $185 and I would still have a compressor with a 9 year old tank that I got about 2 cups of rusty water out of. I think I’ll just “use it up” as you put it and buy new next time. Hopefully the motor or pump will fail and not the tank. OUCH! Tanks for the help Bill. 🙂
Response to comment: Most welcome. Delighted to provide any help. Tell me Ian, is the spelling of HF’s name a Freudian slip?? 🙂
Comment: by: Ian. Purely intentional Bill, purely intentional… LOL
My 5hp 20gal shuts off at 80psi
Not knowing your model, or *how* it shuts off, either your pressure switch is bad/out of adjustment, or if it struggles and blows a breaker it may be valves, if it’s a two-stage.
More detail, or even a few pix of it?
I have a Campbell hausfield model fp209001 it was geitting air pressure then all of a sudden stopped i checked everything and its all fine why wont my tank receive air
Bummer. If you already looked for parts you saw there aren’t any to speak of. You probably have a torn piston ring, but that was only available as part of the pump, which is NLA. So, if you want to fix it, it’ll take some ingenuity. Once you get the pump apart, you can look for “oil free piston ring” and hope you get a match, or something you can modify to work.
Good luck.
I have a Campbell hausfeld model MT500403 air compressor. It builds 80psi and that’s it and runs continuas. What should I do? Thank you.
Start here:
Let us know what you find, please
Good luck.
I have a 2 gallon twin tank CH compressor, model FP2602. It will not build air pressure in the tank. I took of the inlet hose to the tank and air is being pushed through the hose. Any idea what the issue may be?
Tim, you removed the line from the pump to the tank, and you are feeling air flowing, is that correct?
When that line is reattached to the tank, and the compressor runs, you are not seeing any pressure rise on the tank gauge?
That is correct, air was flowing but after reattaching it to the tank there was no pressure on the guage. I also checked the pressure relief and tank drain but both were closed.
Thing is, what may feel like a lot of pressure really may not be when it has to flow against back pressure. I can’t judge how much air is flowing from the pump line to the tank as you can. So, either that there is an impediment for air to get into the tank (is there a check valve at the junction that may have been blocked shut – for example), air is flowing into the tank but the tank gauge has failed and isn’t showing it (let the compressor run for a few minutes, then pull on the PRV… Read more »
Checked the ball valve, it is free, checked the piston rings, look like they could use replacing. Problem is, there is no replacement kit for this compressor, have to buy the pump/motor assembly as one unit and it is a discontinued part. Looks like i am i the market for a new compressor
Sadly, given their relatively low cost, the DIY small compressors appear to be considered “throw away” by the manufacturer/supplier. The cost of acquiring, storing and supplying after market parts would result in parts costing more than the compressor itself. Sorry, but I believe your surmise is correct… unless you remove an existing ring, measure it, and simply google “replacement piston rings” for sources that may supply one identical to those needed. Good luck.
Thanks for the help, already at Princess Auto checking out new compressors, take care.
I have a 20 hp oil less compressor. The issue I’m having is the tank gauge remains on 20 psi and will not move from this reading while the compressor runs . The regulator works fine and I can operate the compressor. Any suggestions?
Chad, if the tank gauge displays 20 PSI and doesn’t move from that, it’s either the gauge itself has failed – but then, eventually, the compressor would stop on high pressure cut out – or the pump is not delivering air to the tank after 20 PSI. If you click on the troubleshooting your compressor link in the left nav column and then scroll down on that page to the pages about why an air compressor runs and won’t build pressure, you’ll quite likely find your answer. If after doing so, and doing the checks referred to, if you still… Read more »
Oil is being pushed out the vent on the compressor?
Perhaps you could add a photo of where on the compressor this is happening, and also the model number? Thanks.