PC Pancake Comp Issue

[brnhornt]

Hey gang....need some help...and this one will be hard to describe.

It doesn't happen every time, but it's starting to happen enough to be a problem.  My pancake compressor will run, fill all the way up, and when the motor cuts off, a leak continues.  It has always hissed a bit after finishing a cycle...but that hiss always tapers to nothing in a few seconds.  The hiss continues until the tank is low enough to try and kick the motor back on.  But the motor doesn't start.  It "jumps" for a half second and then stops.  Sometimes the leak/hiss will continue and after about 5  seconds...it will "jump" again, but not actually run.  What seems to be random luck, one of those "jumps" will be enough that the leak is sealed and the hiss tapers off like normal.  Then after some time, the motor kicks on and the tank fills back up....where once finished it seems 25% of the time the leak will be back and the whole process starts over again.

Anyone experienced that one first hand?

[Bill Wilson]

Mine will occasionally leak air from someplace, after it's filled.  Doesn't do it all the time.

Haven't seem the motor issue though.  Will be following this thread.  I've never been able to isolate where the leak is coming from,

[fixtureman]

Try pulling the little ring to bleed off some air and see if it stops.  that is the unloader valve.

[ajkoontz]

Regulator leaking????????

[KyleD]

As fixtureman mentioned it is most likely your unloader valve not opening correctly. It is there to bleed air out of the compressor chamber and piston so it can start without the resistance of compressed air. The electric motor does not have the torque to start against that resistance and trips the overloads. the jerk you hear is the overloads automatically resetting and then tripping back out. The overloads are not designed to be tripped constantly and will probably fail if you continue running it this way.
 I am not real confident you will be able to find the part you need. These are built to a price and one way they save is to combine all the valves and regulator into one assembly. If that is the case the assembly may approach the price of a new compressor bought on sale. let us know if you can find the part you need at a salvageable price.

[kurt18947]

I had a similar problem but with a Campbell-Hausfeld 11 gallon. The pressure switch and unloader valve were parts of a single assembly. I ordered a new one but could not get it to quit leaking. I returned it and bought separate switch/pressure regulator and unloader valve, got them from Grainger. I don't know that my fix would be practical or even possible on a pancake compressor.

[brnhornt]

Thanks for the ideas everyone!

I pulled the ring when the "problem" was happening, it didn't make any difference.

I opened the whole thing up....and this parts diagram is close enough to what I have:
https://www.toolbarn.com/blogs/parts-sch...compressor
Open the diagram up and look at page two.

So when the problem is happening, I'm hearing the hiss coming from say parts 103, 105, 106, 108.

The valve with the ring on it (part #5) is just a safety valve so the whole thing doesn't blow up.

Should I be looking at part #8 which is listed as a check valve.  Isn't that what should be preventing pressurized air from coming back into the cylinder?

[Roly]

Thanks for the ideas everyone!

I pulled the ring when the "problem" was happening, it didn't make any difference.

I opened the whole thing up....and this parts diagram is close enough to what I have:
https://www.toolbarn.com/blogs/parts-sch...compressor
Open the diagram up and look at page two.

So when the problem is happening, I'm hearing the hiss coming from say parts 103, 105, 106, 108.

The valve with the ring on it (part #5) is just a safety valve so the whole thing doesn't blow up.

Should I be looking at part #8 which is listed as a check valve.  Isn't that what should be preventing pressurized air from coming back into the cylinder?

Yes, try removing and cleaning it out.   May have some debris stuck in it.  Roly

[brnhornt]

Just wanted to close this one out.  Replaced the check valve.  Full tank fill and 8 subsequent top offs and the problem is gone.  I'm calling that a success.  Thanks all!

[Bill Wilson]

Just wanted to close this one out.  Replaced the check valve.  Full tank fill and 8 subsequent top offs and the problem is gone.  I'm calling that a success.  Thanks all!

Where did you find the check valve?  Both Tool Barn and eReplacements say it's not available.