Repair-It

It sounded like something like that but I assumed the valves were all in the valve block, and replacing it would address anything like that.

I thought so too. I wonder if it's some kind of anti-deflate-from-catastrophic-airline-failure for the front strut to prevent a crash if the front bumper got ripped off.

The saga continues:

Anti-reversing valves (ARVs) came in about 7:45 last night. I installed both and recharged the system (I had picked up another nitrogen bottle yesterday). Bag-fills and tests went smoother than in the past, partly because I'm practiced and partly because I think the front struts were dropping correctly when commanded. Reset ride height calibrations, which I guess is recommended at each valve block change? The configuration then was with the original compressor/valve block and new ARVs. System seemed to work OK until I attempted the Park ("entry/exit") height. As the reservoir got above about 150-160 PSI the old compressor just couldn't seem to hack it (I believe "nominal" max pressure at Park height is somewhere around 175 psi). The system timed out the compressor and declared the change in height "failed".

Decided to reinstall the RMT compressor/valve body, since I'm now thinking that the old compressor was shot. Completed the install, rebooted and reset everything with another nitrogen fill. Cycled through all normal tests, all seemed good. Test drove, time to reach "Aero" height was faster than I ever remember, and return to normal seemed OK. Seemed like more-than-I-would've expected run-time on initial start and driving, but it seemed to settle out after driving some and compressor run was not excessive.

Let it sit overnight and checked the system stats before I started it this morning. Air reservoir was at 1 bar. So now I believe I have either a tnak valve or line-to-tank leak. I have only messed with fittings at the valve body assembly, and I was suspicious of low tank pressure once before with the RMT valve body. Overnight Monday-to-Tuesday I had the system sit with the original valve body/compressor and the reservoir held fine. So now I think I have some leak in the air tank circuit on the RMT unit, which is otherwise working well. When I get some time today I'll pull the wheel/inner fender again, repressurize the reservoir and see if I can find the leak. If no leak is found or corrected, I'll pull back off the RMT unit, swap compressors, and reinstall the original valve body with the RMT compressor.

So, to summarize, I think there are 3 causes of the disaster this has turned into:
1.) Failing anti-reversing valve that prevented a front strut from dropping correctly
2.) Tired 17Xk mile, 12+ year old original compressor
3.) Leak in the RMT air circuit/valve for the tank

Hopefully fully addressing all 3 of those get me there.

Sheesh.

Put air in the tank and pulled the wheel and inner fender off again. Could hear nitrogen hissing in the compressor area. Couldn't find a specific leak, soaped all connections and no evidence of anything.

Called RMT and asked for a warranty replacement - they said no problem, I'd just have to pay up front and wait while they built it up.

After removal I found a rolled o-ring in the compressor, that is hopefully my leak. Sent them a picture and asked if I should attempt to correct. They said if I was comfortable repairing I should give it a shot, and that I should apply grease to the o-ring. I'll attempt it and see how it goes.

Disassembled, reinstalled the o-ring, and reassembled. Put the unit back in but hooked up just the reservoir line. Seems OK so far after like 10 minutes. We'll see if it holds well for a couple hours before I reinstall everything else.

Held fine for a couple hours and again overnight. No excessive compressor runtime. Seems sorted at least for the moment. I emailed RMT that it appears to be successful at least so far. I did ask them if they could discount a couple anti-reversing valves for me as compensation (maybe they'll just send for free?). Thought it was at least worth a shot.

They offered 15% off, which at $60 ea is at least a few $'s. Need to decide if I want to carry on with my Amazon cheapos or upgrade...