air compressor does not turn off at pressure, pressure relief valve lets off pressure

[cody michael]

air compressor does not turn off at pressure, pressure relief valve lets off pressure at 180 lbs. this is worrying me and I am not going to use this until I get it fixed. any ideas. I am assuming the pressure switch is getting stuck, is this something that could be cleaned or needs replaced? it is about 2 years old maybe used 10 times for a few minutes (pump up tires etc) I was using it for the first time with impact gun to remove car tires when this happened.

it is this compressor

http://www.homedepot.com/p/Husky-20-Gal-Portable-Air-Compressor-F2S20VWD/203187354

If I need to buy the switch is there a cheap source online?

[John Coloccia]

air compressor does not turn off at pressure, pressure relief valve lets off pressure at 180 lbs. this is worrying me and I am not going to use this until I get it fixed. any ideas. I am assuming the pressure switch is getting stuck, is this something that could be cleaned or needs replaced? it is about 2 years old maybe used 10 times for a few minutes (pump up tires etc) I was using it for the first time with impact gun to remove car tires when this happened.

it is this compressor

http://www.homedepot.com/p/Husky-20-Gal-Portable-Air-Compressor-F2S20VWD/203187354

If I need to buy the switch is there a cheap source online?

It has a two year warranty, so I'd call the company first.

[cody michael]

it is just over that. and it was a replacement on my first one that broke, so probably a year out of warranty.

[Bruce Page]

It's likely that your pressure switch is bad. Not hard to replace or terribly expensive.
According to the guide for your machine it is item# 50 part# E101713

http://www.mastertoolrepair.com/pressure-switch-e101713-p-21036.html

[cody michael]

I am not sure if this helps or not, but the on-off switch does not work either.

my setup is I have this compressor in my garage attic, and I have a wireless switch that I use to turn it off and on. last night I went to check the symptoms and it over pressurized, so I flicked the on of switch and nothing happened, is that switch the same as pressure switch? or a different one?

so do I need to order pressure and rocker or just the pressure switch? is there any reason using wireless switch to turn on and off would cause this?

[Curt Harms]

I agree with Bruce. I bought a Campbell-Hausfeld some years ago. Mine is horizontal but similar. The pressure switch/unloader mechanism was really cheesy. I bought a replacement from C-H and couldn't get it to stop leaking. I returned that, went to Grainger and bought a separate power/pressure switch and inline unloader. No more issues in 15 years or so.

[cody michael]

I agree with Bruce. I bought a Campbell-Hausfeld some years ago. Mine is horizontal but similar. The pressure switch/unloader mechanism was really cheesy. I bought a replacement from C-H and couldn't get it to stop leaking. I returned that, went to Grainger and bought a separate power/pressure switch and inline unloader. No more issues in 15 years or so.

could you show me an example of this. how much did that cost?

[cody michael]

I agree with Bruce. I bought a Campbell-Hausfeld some years ago. Mine is horizontal but similar. The pressure switch/unloader mechanism was really cheesy. I bought a replacement from C-H and couldn't get it to stop leaking. I returned that, went to Grainger and bought a separate power/pressure switch and inline unloader. No more issues in 15 years or so.

I am very interested in copying your setup, but I am not familiar with compressors, could you show me what you bought?

[Curt Harms]

I am very interested in copying your setup, but I am not familiar with compressors, could you show me what you bought?

I'm not finding the exact switch I bought but it is very similar to this:

http://www.amazon.com/Air-Pressure-Switch-Single-Stage-Dual-Stage/dp/B0000AXCUL/ref=pd_sim_sbs_hi_2?ie=UTF8&refRID=0SYS35WDM1V7P6MSQ9N8

This appears to have two connections, one threaded and one compression. I'm guessing - you'd want to make sure before you buy - that this switch incorporates an unloader. Mine does not, I had to install a separate device. The unloader vents any pressurized air from the compressor so the motor isn't trying to start against compressed air in the cylinder(s). If the unloader doesn't work, the compressor is likely to trip a circuit breaker because the starting load is too great.

Amazon also has a less expensive switch but the brand/quality is unknown:

http://www.amazon.com/Pressure-switch-compressor-95-125-unloader/dp/B00273Q3ZE/ref=pd_cp_hi_1

[Myk Rian]

The one on my HF compressor gets stuck turning on. The first one Curt linked to looks like a good one.
http://www.amazon.com/Air-Pressure-Switch-Single-Stage-Dual-Stage/dp/B0000AXCUL/ref=pd_sim_sbs_hi_2?ie=UTF8&refRID=0SYS35WDM1V7P6MSQ9N8

[cody michael]

I'm not finding the exact switch I bought but it is very similar to this:

http://www.amazon.com/Air-Pressure-Switch-Single-Stage-Dual-Stage/dp/B0000AXCUL/ref=pd_sim_sbs_hi_2?ie=UTF8&refRID=0SYS35WDM1V7P6MSQ9N8

This appears to have two connections, one threaded and one compression. I'm guessing - you'd want to make sure before you buy - that this switch incorporates an unloader. Mine does not, I had to install a separate device. The unloader vents any pressurized air from the compressor so the motor isn't trying to start against compressed air in the cylinder(s). If the unloader doesn't work, the compressor is likely to trip a circuit breaker because the starting load is too great.

Amazon also has a less expensive switch but the brand/quality is unknown:

http://www.amazon.com/Pressure-switch-compressor-95-125-unloader/dp/B00273Q3ZE/ref=pd_cp_hi_1

in the description it says "On/off switch plus built-in unloader for loadless starting" that was what you were talking about correct? it appears it does have an unloader.

[cody michael]

would this work? I don't use the on/off switch with my current setup

"http://www.lowes.com/pd_506592-296-FHG2J27BP_0__?productId=50022504&Ntt=square+d+pressure+switch&pl=1&currentURL=%3FNtt%3Dsquare%2Bd%2Bpressure%2Bswitch&facetInfo="

or this one

http://www.menards.com/main/plumbing/pumps-well-tanks/accessories/square-d-reg-air-compressor-pressure-switch/p-1946433-c-8672.htm

[Don Morris]

If a 20 gal compressor blows it can be disastrous. Get that puppy fixed. When my 20 yr old Craftsman started to act up, I looked into repairing it and found that old ones can blow up. I decided to replace it. A fairly new one isn't likely, but overpressuring isn't helpful and the photos of a 20 gallon tank that did blow was eyeopening.

[cody michael]

If a 20 gal compressor blows it can be disastrous. Get that puppy fixed. When my 20 yr old Craftsman started to act up, I looked into repairing it and found that old ones can blow up. I decided to replace it. A fairly new one isn't likely, but overpressuring isn't helpful and the photos of a 20 gallon tank that did blow was eyeopening.

Yes, I agree. I am not using it until it gets fixed. I am just trying to figure out best/cheapest way to get it working again.

[Curt Harms]

The one from Menards looks like a better bet to me. The one from Lowes looks like it cuts out at 100 PSI. If that is not adjustable and if the differential is fixed, it'd probably cut in at 70-80 psi or so. That might be a little low for some uses. Mine is set to power on at 100 psi and off at 120 psi. I copied the Menards Square D model # and googled it. One of the images shows the back and it appears to have the two connections (air pressure and unloader) so it may well have the unloader built in, the Menards blurb doesn't say.

Don is correct about the danger of an overpressurized or corroded compressor tank. There is a second overpressure protection device which I assume is working properly. You use a remote power switch so just leave the lever on the pressure switch in the "on" position.

[Mark Wooden]

[QUOTE=cody michael;2326484
If I need to buy the switch is there a cheap source online?[/QUOTE]

A cheap switch and regulator are the problem to begin with- be safe and get a good one. When the rest of the compressor dies, you can still keep and use the switch and regulator again

[Tom M King]

I replaced a pressure switch not long ago with one I bought off ebay, but I had second thoughts about it, and got one of these: http://www.northerntool.com/shop/tools/product_42428_42428 That one looked a lot more like the one that had lasted since 1973 or 4.

They come in not only different max cutoff pressures, but all sorts of sizes and numbers of connection points for pressure lines.

Northern Tool has a good selection of decent parts but I didn't find much selection online. Here's a good list: http://www.zoro.com/g/Pressure%20Switches%20-%2060%20to%20200%20PSI/00155552/?category=4518


Some years ago, I got tired of a compressor leaking down, so I took all the fittings apart, and used this stuff. http://www.gasoila.com/fasseal-ats-anaerobic-thread-sealant-with-ptfe.html It always holds pressure since. I need to do the others, but haven't thought about it at the right time. Not cheap, but does work, and keeps on working: http://www.mscdirect.com/product/details/36913077

[cody michael]

would this work? I don't use the on/off switch with my current setup

http://www.lowes.com/pd_506592-296-FHG2J27BP_0__?productId=50022504&Ntt=square+d+pressure+switch&pl=1&currentURL=%3FNtt%3Dsquare%2Bd%2Bpressure%2Bswitch&facetInfo=

or this one

http://www.menards.com/main/plumbing/pumps-well-tanks/accessories/square-d-reg-air-compressor-pressure-switch/p-1946433-c-8672.htm

can anyone confirm either way if this square d switch is the same as the northern tool one? or is this an inferior version?

[Jerome Stanek]

I had to replace the switch on mine and got a square d and it failed in about a year. I ended up getting one that had a higher amp and that one is working fine. I also added a relay valve so it shuts the air off when I shut my lights off

[cody michael]

Is the one from lowes or menards comparable to the northern tools or amazon ones?l

[Tom M King]

If it's a Square D, they will all be the same, as long as it's the same amperage one, with the same fitting/fittings for the inlet. Notice in one of those links I posted that there is a long list of possibilities, not only for various pressures, and various inlet types, but various HP motors too. You need the right one.