Why does my compresser "clack"?

Thanks for the idea Ed.

The clacking would also happen BEFORE the regulator. Back then, I was running the AB directly to the compressor via that little bleeder thats in the picture above. When it would clack then, I figured it was cause I had the bleeder closed too much and so I would open it some and I think it would releive the clacking.

But now with the regulator, when it started to clack, I lowered the pressure all the way(without opening the bleeder valve) to see if it would help and no, it wouldnt. It wouldnt stop till either I opened the bleeder/moisture valve, or unplug it and then start it up again.

 I will wait for a few more responses, and see if I get any info. If not, I will contact paasche.

Thanks again.

A D500 is a diaphragm-type compressor.  It has a shaft connected to the motor which drives a rubber diaphragm up and down.  Each up stroke makes a puff of air.  There is a backflow valve which prevents the air from getting sucked in during the down stroke.

If the clacking started when you installed the regulator, what I suspect is happening is that the air pressure which is puffed out on the pressure stroke has no place to go when held in place with the regulator.  The diaphragm has no place to go and is causing the connecting rod to rattle, especially on the exhaust stroke.   It can't be good for the compressor.  Over time it may tear the diaphragm.

I don't have a quick fix in mind.   I would suggest that you contact Paasche and explain your situation.  They must have a contact us page on their website - google Paasche.  See if they have a solution.   It may involve adding an expansion tank between the compressor and the regulator.