kdburtch

Im sorry if this has been posted before, but I could not locate this exact issue. On my GX (03, 171,00 miles) the rear suspension only intermittently drops. Some times it will drop all the way in 4 hours and sometimes it will hold rear height for 3 days without driving. The compressor works and inflates it back up without issue. Was going to get new air-bags to replace but I am worried something else is going out. Would faulty height sensors do this when the truck is off overnight? Any help would be greatly appreciated.

GreggyG

It's likely leaks in one or both bags, I would start with that. I have a set of my olds bags if you are interested, one is good, the other one has a small leak, if you want to start with one bag, that may work, I also have the height sensors if you end up needing those.

IanB2

If it leaks down on one side when shut off, I'd expect you've got a small leak in one of the bags.

The decision to repair or convert to coils is a tricky one...the air system is 15 years old now, what and when will the next component fail? Impossible to know. Rear coil conversion can be done for under $300 and you never have to worry about it again.

bufferdan

I have exact same issue with my 04 with 170k. Holds air fine for days on end and then randomly will be sitting on bump stops after sitting for a few hrs. I got some new aftermarket bags to swap them out but going to wait until it becomes more prevalent i guess.

CodeMunkee

As stated elsewhere, you have a leak in one or both of the bags. In my experience, the intermittent behavior is because of the air pump overheating since it has to stay on continuously to keep the bags inflated.

I asked my mechanic and he swapped out the airbags for 4-runner springs for $800 parts and labor and it's been amazing ever since.

kdburtch

does the air compressor run when the vehicle is off?

CodeMunkee

No, it only runs when the vehicle is on, so you will either go out to the thing after it sits and it will be flat OR there's a couple stationary positions that pinch off the hole and makes it appear that it's not losing air, until you move (had this happen to an Audi Allroad as well). I also found (before I did the coil swap) that if you're bouncing all over the place, you can stop for a bit and then power cycle the rig until you hear the compressor kick in.

chiph9

However the release valve will operate with the key out (to lower the vehicle). You can see this if you get a couple of friends to step out after shutting the engine off.

Chip H.

bufferdan

I've noticed that mine is doing it if i park on a very uneven or inclined surface. I think it try's to level out with the front and will release the air out of the bags when i turn off the vehicle.

childerj

Just did the spring conversion due to this same issue. Mine went downhill quickly. Woke up in the morning to a flat suspension but it would re-inflate if I chose high mode. 3 days later it was dead. Wouldn't re-inflate and wow what a bouncy ride.

Full conversion including parts and labor was $550.

kdburtch

Well for $90 (for both) airbags on Amazon I thought it was worth a shot. Almost gave up and brought it to a shop until I saw a video on a Toyota sequoia and the clips, then it was 30 minutes per side to replace. Has works flawlessly since and the old bags were very dry rotted, but for 16-17 year old parts I dont think that's too bad.