Autoride Mystery!

[Sarge]

09 Yukon SLT with Magnaride in front and AutoRide in back. Front has a 2'' spacers and rear has a 1/2''. Links have spacers on rear to adjust vs stock.

Anyways replaced the whole rear compressor unit about 6 weeks ago, went with Arnott complete replacement unit. Installed everything worked fine. Until about a week ago where it would keep turning on and 50% of the time the truck would air up, others it would just run but not air up. Figured the pump was bad.

Last week I replaced the pump again with a new unit. This unit was very quite vs the first so I figured my first one was bad. Installed pump, new relay, checked fuses and unhooked battery. All air hoses/ connectors where fine also. Everything was fine. Started, ran for about 30 secs, everything aired up fine.

Now a few days later its happening again. If i go out and start, it may run for 30 secs +/- and air up fine and hold until i let it sit before it releases air.

Sometimes i can start it and hear the comp kick on but truck does not raise up.

Sometimes if i turn the truck off and let it sit, try again it may air up but could take 60-90 secs.

Whats going on? Lines look good, shocks. No codes, ive discounted battery many times to "reset" system.

Almost like truck is getting confused and needs a hard reset for comp? When the truck does not air up, its not purging out either through the separate line.

Any help would be great!!! Thanks

 

[Sarge]

Did it this morning.

Started it, aired up fine, held.

2nd start, comp kicks on, truck does not raise.

3rd start, same, kicks on no raise

4th start, kicks and and raises. Holds.

Within 5 hours

Ugh

 

[Doubeleive]

maybe you have a faulty height sensor?, pull the air lines, reconnect air lines, run a scan in real time at startup to see what reading you get from sensors.
just an idea anyway...

 

[adventurenali92]

It your air shocks are totally shot and not holding air. 90% of the time, that’s what’s wrong and they compressor just keeps running to keep them full, despite the air leaking out of the shock. The rubber bladders on the air shocks are more than likely torn and don’t hold air.

 

[Sarge]

Shocks look great. I wouldn't think there is a leak, because when it works, it works. It will stay aired up all day when it works. Height sensor is a good idea.. need to find a big boy scanner.

 

[adventurenali92]

Shocks look great. I wouldn't think there is a leak, because when it works, it works. It will stay aired up all day when it works. Height sensor is a good idea.. need to find a big boy scanner.

Sometimes the leak in the bladder is small and the air will seap out slowly. Do your shocks hold air for more than a day at a time? Also have you had them aired up and then tested for leaks with soapy water?!

 

[Sarge]

Yes they have held all day and night before. Most of the time the system will purge when i park after it sits for a hour or so. I did spray soapy water when they aired up and let it sat, couldn't find leaks

 

[02Lightning]

I thought it purged some of the air off every time the vehicle is shut off. Then when started again, it would go thru it's test cycle and air up the system again.

 

[Sarge]

Mine sometimes purges after i park and lock it. Sometimes it wont. My system is just crazy

 

[al2fast]

Shocks look great. I wouldn't think there is a leak, because when it works, it works. It will stay aired up all day when it works. Height sensor is a good idea.. need to find a big boy scanner.

I got one of these scan tools. All sorts of live data I don't know what to do with for all the various sensors, reads the Z55 suspension codes, shows the voltages for the ride height sensors on all 4 corners. All it does is read and reset codes to the best of my knowledge, no relearn procedures.

https://www.amazon.com/iCarsoft-i90...qid=1517460463&sr=8-1&keywords=i900+scan+tool