I bought a used air suspension compressor for my 05 XJ8L. I want to test the compressor before installing it. Can I test it on the bench? There are 2 large wires (red & black). Can I apply positive to the red and negative to the black? If compressor runs, I assuming I could plug the vacuum line and it should cut off? Any advice much appreciated. I do not want to ruin a potentially good comoressor.

THANKS!

​​​​​​​Richard

 

Hi Richard,

Yes, you can bench test the compressor motor by applying +12 volts to the Red wire and ground to the black wire. There is no thermal safety cutoff so do not run the motor for more than 120 seconds at a time, and allow 45 seconds of cooldown minimum before running the motor again.

The Blue and Yellow/Blue wires are for the exhaust vent valve.

Plugging the intake port will not cause the motor to shut off but may put undue strain on the motor so there is no reason to do it.

To test the output of the compressor you would have to attach an air pressure gauge that can measure about 250 psi to the output port and you would have to run the compressor for up to 120 seconds into a sealed system to see what maximum pressure developed.

What were the symptoms of your old compressor that prompted you to purchase the replacement? The most common problem is a worn piston ring seal, which can be easily replaced with a new one from bagpipingandy.com. See the photo albums at the link in my signature line to see how it's done.

Cheers,

Don

 

Thanks Don! This is exactly what I needed.

I do not have a problem with my current compressor, and got the used compressor as a backup. Honestly, I forgot about the piston rebuild. The salvage yard let me have the compressor for $25.00 with a 30 day warranty. Hope I didn't do too badly?

Richard

 

That was a no-brainer!