Sorry for the delay...

That does seem like the correct pressure switch, yes. If the max PSI rating is 125 and you're seeing 140 PSI on your tank gauge (assuming the gauge is accurate), that would be indicative of a defective pressure switch. Every now and then we do see new switches having this problem, so it's not unheard of.

I would try adjusting the high-end cut-off PSI first, as you may be able to decrease the cut off pressure.

You can watch a video on how to do just this at the below link:
www.mastertoolrepair.com/how-to-adjust-p...-switch-p-30582.html

There should be a differential adjustment screw in your switch to adjust this, I would start by turning it 1/2 turn C.C.W. to see if that does the trick; if not, adjust it another 1/2 turn CCW.

Hopefully this helps,

- MTR

You can find a breakdown of your compressor and the manifold/control assy by clicking on the below link:

www.mastertoolrepair.com/portable-oil-ba...502513-p-748816.html

The problem is that Coleman used a few different types of switches on this unit during its production, so it can be confusing.

Which pressure switch on the above page does your original pressure switch look like? The most popular switch used was a Furnas pressure switch, which is probably what you had. What you have now is Condor-branded switch and it should work, but the Furnas switches are made better (IMO).

Do you have the original switch still?

- MTR

I'm sorry to hear this, it's quite perplexing to say the least...

You may have already done this, but just to be safe I would do the following:

1. Turn off the unit
2. Drain all of the air from the tank
3. Remove the plug
4. Install teflon tape on the plug.
5. Reinstall the plug.
6. Test

- MTR