Air bags look squished in the morning.

Yup. And a great way to find those is when they're wet. An air hiss you otherwise wouldn't hear gets louder and can sometimes be seen when bubbling through water.

 

They should not deflate overnight loaded or unloaded. Seems like there is a leak in the suspension system (assuming your air tanks are still well pressurized).

 

You may not hear an air leak on the air bags, but it's the 1st to go when there is a leak. Over night is not a big deal, just about every truck I drove with air ride, ( except for the 1 or 2 new trucks I drove) the bags were flat after sitting a while. Like Bob sez, leaks are best found when everything's wet.

 

Hey Captain, I'd like to see the facts on that 60% statistic please.


Thanks,
Mr. Always 100% Right

 

Take out the spray bottle of Windex and pin point the leak. That way you'll know if your gonna be sitting at shop for 2 days or have it fixed on your next 34.

 

I would almost guarentee there's more than that wrong. Have you read any of his other threads?

 

I've had newer trucks that don't drop much pressure at all overnight and older ones that are like Whack-A-Mole with minor air leaks everywhere. You want to keep an eye (ear) out for them and get them fixed when you find them, but oftentimes they aren't severe enough to be dangerous or illegal. Right now, I'm dealing with a leaking seat air bag. That is the only significant leak I know of, but I swear that alone is enough to run most of the air down overnight and cause the truck's air bags to be deflated even as a bobtail. It is certainly not ideal, but I'm not sure what to do about it. I should speak up, since I finally work for a place that fixes everything. I guess I'm still in the mindset of letting minor things slide.

 

Good advice. Build up pressure, then shut it off somewhere quiet where you'll be able to hear the leaks. The windex will bubble up at the site of a leak.

 

True, Bob D. There's a lot of system in these trucks, primary and secondary. I've been refreshing myself chasing air leaks for about 2 months now, so it's pretty fresh information in my truck. I replaced the tractor air suspension bags 2 months ago because of deep cracking and leaks. Then my compressor went out, replaced that, purge valve, and D2 governor. Bad governor, replaced it again....still leaking pretty bad. Not 4psi in 1 minute, but bad enough. Replaced cab air bags (one had a major hole) things got quiet, then started losing pressure again. Found a big hole in a cab air bag, replaced the two bags and leveling valve. All quiet for a week or two, then started losing pressure again. Found a nice leak at the air hose for my cooling fan, and a nice trim on the hose and reset the quickconnect fixed that. We quieted down again, now losing pressure once more. I got a new bottle of 409 (my leak finder of choice) and will attack again once I'm working, heading out Wednesday AM. I'm going to check closer on my seat bag, as Bob D mentioned earlier. I've checked all the fittings so many times they're all bright and shiny now, but I haven't checked the seat air bag lately.

Keep looking, OP. Air leaks are pretty easy to repair, mostly, but can be hard to isolate if there's noise around you when you're listening for that hissing sound. Best!

 

Sounds like someone has put something in the air system at one time that should have not been put in. Never heard of so many air leak issues on one truck. Maybe the dryer is bad and releasing all sorts of contaminants into the system.

Sounds like a case for Dr. House M.D.