Air ride or springs?
Hi everyone. Longtime listener. First time caller. Lol.
I've got a 2008 Envoy Denali 4wd with rear air suspension. The truck has about 135k miles. I've read many of the different posts about suspension, but at this point, I'm not positive what my next step should be. We recently replaced the rear suspension bags because they were leaking due to dry rot. We didn't replace any other parts. At the conclusion of the work, there didn't appear to be any other leaks in the system and the truck was back to normal. But now, 2 weeks later, I'm back to having a truck that won't fully inflate the bags. It isn't squatting to the stops like it previously was, but it won't inflate the bags at all. They are "stuck" at the current low fill.
Here's what has occurred over the last two weeks:
The driver's side bag had a noticeble leak that you could often hear. The compressor would air system up to appropriate height. But overnight, the system would leak air and often be squatting on the stops. Upon turning the truck on, the bags would fill to normal ride height and be good for the day. The truck ultimately got to the point that the bags would no longer fill at all. The compressor would kick on and run, but bags wouldn't fill. We ended up replacing the bags with the assumption that the compressor was still okay.
After replacing the bags, the compressor kicked on and aired the bags up to normal fill. Everything went well for about 4 days. The system wasn't leaking. The compressor would run for a few seconds at a time. Then the truck started to slightly squat again, and the bags wouldn't inflate. They remained partially inflated. This went on for 3 days. We adjusted the ride height sensor on both sides to see if this would cause the truck to add more air to the bags. Nothing happened immediately, but later the next day, I turned the truck on and the bags aired up again to normal fill. The system was good for 2 more days, but now it is back to having bags that are only partially inflated. The compressor runs for about 30-40 seconds each time the truck is started, but doesn't fill up the bags. There are no lights or warnings visible on the dash display.
I know there are several options at this point. Here are the options that we're considering, in no particular order. What are the recommendations of this group?
1) Replace bags with springs. (~$170 with new shocks)
2) Replace check valve on compressor. (~$40)
3) Replace compressor. (~$400)
4) Bypass compressor with push to connect 5/32 hose tee. (~$10)