auto leveling problems

[jon1118]

I purchased a 2004 LeSabre a year and a half ago with almost 40k and now have 68k. This car has been great, but now the rear suspension needs repairs. After searching this site and finding similar problems, they just didn't seems to be identical.

So the problems and details which may be related: the rear end never returns to lowered position and is constantly at max height of leveling system, seems like compressor runs normally but thinking sensor may be faulty, rear tires are now pitched in on the top side.

I need to have new tires installed and have always just changed shocks/struts based on tire replacement. So just wandering if shock replacement is fairly simple on this vehicle and if that will fix my problems.

I appreciate anyone's advice and expertise.

Thanks in advance, Jon

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[HotZ28]

From the info given, it sounds like you have a problem with the level sensor, or compressor exhaust valve. Have you checked underneath to be sure the linkage (rod) on the lever is connected to the lower control arm? Replacing shocks are not that difficult, but you need to get the ride height problem resolved first. Once you get the correct height, you may find that the shocks are fine.

 

[jon1118]

I just got around to checking linkage, looks fine. Any idea how to check level sensor and exhaust valve. Thanks for the help so far

 

[HotZ28]

After first turning the ignition switch ON, wait until the compressor runs for a few seconds, then turns OFF. You should then here the compressor relief valve open (if you can hear well), and if does not exhaust, you need to follow the troubleshooting procedure outlined in the FSM. I do not have a copy of the FSM, or procedure for your particular year, but it should be available at your local library.

 

[jon1118]

thanks for the help so far. so today i removed the linkage to the sensor and manually exercised the switch up and down a few times. then i reinstalled and disconnected air lines from shocks to release air. i then ran the car until the compressor ran a full cycle. the shocks returned to max height and the compressor relief valve did operate. while the car was running and the rear end at max height i did sit on the bumper which caused the compressor to kick on. i then removed the linkage to the switch again while car running and moved the switch up and down to check for change, moving the switch in the down position did kick on the compressor and raising the switch would turn it off. any ideas?

 

[HotZ28]

There is an 10mm bolt on the switch linkage that can be loosened to adjust ride height. Were the air shocks replaced? If so, and the linkage was not disconnected, it may have moved on the lever. It takes very little movement (1/16") to make a big difference in ride height (psi). You might try making an adjustment on the lever to see what happens.

 

[jon1118]

I did not replace the shocks. I did disconnect the linkage to the sensor, but the linkage is not adjustable. Does is sound like the sensor needs to be replaced? For some reason I am thinking it is a faulty sensor

 

[HotZ28]

It could very well be the sensor. If so, Click Here for assembly diagram & part numbers. Click Here for best price.

 

[jon1118]

replacing the sensor did fix the problem! thanks for all the great advice and information. so when i started the car after replacing the sensor the compressor kicked on then off right away and the check valve released until the car returned to its normal state. thanks Z28! now its time to do a trans filter service.