rear shocks air pump

As it's a non-servicable unit there is no exact lube for it. but if you believe the compressor is good then just a small amount of compressor oil. If you use too much it will deteriorate the lines and air bags on the shocks. To be safe I would replace the entire compressor unit.

thanks. considering locating manufactureer 0f piston housing with new piston. seems to have a graphite type abstance for lube.

Sorry to say but they no longer make graphite compressor oil due to graphite build up. Now you could mix some graphite into some compressor oil if that's what you desire.

Thanks for the points.