California Air Tools Compressor - Cold Start Valve issue

[Slowbra]

I’ve got a 6yr old 10gal CAT-10020 air compressors that started acting up this weekend.

At first I noticed the air compressor didn’t kick back on when the pressure dropped during use. Come to find out the breaker tripped and so I reset it (it was an odd thing to occur since only the TV and compressor were on that circuit at the time). I restarted it and a few minutes later It tripped the breaker again.

I reset it again and this time noticed the cold start valve never closed (meaning the air that the compressor was building was constantly leaking out). This valve is designed to close shortly after start/pressure is built. Because this wouldn’t close the compressor kept running - the pressure gauge stayed around 10psi and I can hear/feel the air coming out of the cold start valve.

Does this sound as simple as a cold start valve replacement, or is the fact that it tripped the breaker twice a sign of something else that I should check first? The compressor wasn’t on long enough to suggest overheating caused the breaker to trip.

Background: It’s been sparsely used, is never stored overnight with air, and has been a great compressor until Sunday.

 

[The Cobbler]

cold start valves usually close around 15 psi I thought . maybe you have a leak /issue somewhere else?
I would try removing & blocking the cold start valve & see what happens with the pressure

 

[LXCam]

Check the contacts on the air pressure switch or if it has a magnetic starter. You’ll probably find they’re burned up and need to be dressed or replaced. Burned contact will cause a voltage drop this increasing the current draw. As for the bleed valve, I’m don’t know how that’s actuated.

 

[Slowbra]

cold start valves usually close around 15 psi I thought . maybe you have a leak /issue somewhere else?
I would try removing & blocking the cold start valve & see what happens with the pressure

I’ll give that a shot.

Check the contacts on the air pressure switch or if it has a magnetic starter. You’ll probably find they’re burned up and need to be dressed or replaced. Burned contact will cause a voltage drop this increasing the current draw. As for the bleed valve, I’m don’t know how that’s actuated.

I’ll take it apart to see what I can. I’m still not sure about the cold start valve, but will check for leaks elsewhere that may be contributing to this.

 

[Slowbra]

With the cold start valve the unit is building pressure, but it does appear to be struggling to get past 62psi. In full disclosure I couldn’t seal the cold start valve completely. It does appear to be building pressure slower.

I’ll take a look at the pressure switch next. Any other thoughts?

 

[The Cobbler]

I would look for a leak in the plumbing from the compressor to the tank ( anything on the compressor side of the check valve in the tank), including leak at pressure switch . bad head gasket, worn rings, etc
soap up all of the connections and run it to see if you get bubbles

 

[Slowbra]

I would look for a leak in the plumbing from the compressor to the tank ( anything on the compressor side of the check valve in the tank), including leak at pressure switch . bad head gasket, worn rings, etc
soap up all of the connections and run it to see if you get bubbles

Pressure switch visually looks good. No leaks externally between compressor to tank nor pressure switch. I am wondering if there isn’t something up at the pressure switch given that I did trip the breaker twice before and now it’s building pressure slowly.

 

[The Cobbler]

I think you either have low compression or a leak somewhere causing the low/slow pressure build . a bad pressure switch wouldn't really cause slow build .
does the motor seem to be turning as fast as usual?

 

[Slowbra]

Motor sounds normal. I ran the unit for 50seconds with the cold start valve and it didn’t get past 15psi. With the cold start valve removed (and plugged in a non-elegant and sealed way) it got up to 62psi in that same time. However it wouldn’t go further in a short amount of time more. I will try a better seal and check for leaked again.

 

[Slowbra]

Looks like it was the exhaust valve. It’s an extremely thin piece of metal that appears to have broken.

I’m able to still source the item although it’s highway robbery at $34 for a single thin piece of metal. Any idea what this is made out of? I’m likely going to make my own rather than pay $34 for it.

It looks like the seal may have survived so it’s only this item that is needed.

 

[The Cobbler]

I've read where people use feeler gauges to make them.

 

[Slowbra]

That is fantastic! I have plenty of those.

 

[Slowbra]

Air compressor’s exhaust/reed valve was replaced using feeler gauges cut to size. All works well again!

 

[The Cobbler]

great .