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Front end dropped on wheels. Suspension?

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Old 11-21-16, 08:58 AM
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hippchip
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Unhappy Front end dropped on wheels. Suspension?

Hey guys. I just finished replacing the rack and pinion, outer tie rods and front brakes and had a floor jack from the front to jack it up at the cross member when I removed the jack stands. When I lowered it, the jack got stuck, so I got another jack and raised it up, removed the floor jack and lowered it back down. Only now the front end is sitting on the wheels like the air suspension system is damaged. It was dark and I had already been working on the car for several hours so I called it a day. Does anyone have any ideas on what might have happened?
Old 11-21-16, 09:11 AM
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rkw77080
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It sounds like the air suspension system vented the air when the front tires were lifted off the ground. Have you tried starting the engine and let the compressor fill them back up?
Old 11-21-16, 11:48 AM
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hippchip
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Not yet, wouldn't that be nice? I was thinking when it lowered on the jack it might have damaged something.

Last edited by hippchip; 11-21-16 at 11:51 AM. Reason: add info
Old 11-21-16, 03:08 PM
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hippchip
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Started it up and it did not raise up. Tried setting height control to high. Got the high indication but front end didn't move. Lifted car up and there's nothing under where the jack was located to damage. Was fine before I jacked it up. Pun not intended.
Old 11-21-16, 03:46 PM
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BradTank
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Maybe an air line got pulled out accidentally?
Old 11-21-16, 05:34 PM
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rkw77080
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Here's long shot, but check to see if you have re-installed the height sensor properly, and make sure you did not unplug it accidentally.

Last edited by rkw77080; 11-22-16 at 03:29 AM.
Old 11-21-16, 06:03 PM
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hippchip
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How does it plug in? Vacuum? I never disconnected it. I have a feeling this is related.

Last edited by hippchip; 11-21-16 at 06:06 PM.
Old 11-21-16, 06:16 PM
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rkw77080
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The sensor is electrical. It translate the linkage position, which is attached to the lower control arm, how high the vehicle is sitting. So if the linkage is detached, the sensor will "think" that your car is sitting too high and open the air valve to try to lower the car.

Last edited by rkw77080; 11-22-16 at 03:29 AM.
Old 11-21-16, 06:41 PM
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hippchip
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The linkage is attached and none of this was ever disturbed
Old 11-21-16, 06:55 PM
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takimanpgt
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Please take a pic of your sensor and linkage after lifting the car up and removing the wheel(s). You seem to have worked on the rack/pinion and tie rods so you may have mistakenly done something around there. Also - you are not providing enough details. When jack failed, where did you jack the second one? Does the air compressor turn on? Does lowering or raising the car do anything to the rear air suspension? Did you check for air leaks with a friend sitting by the front end of the car?
Old 11-21-16, 07:32 PM
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hippchip
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The second jack was the scissor jack attached just behind the front wheels. Then I put on jack stands. I will send pic in the am. The wheel is off and it's jacked up. So I was thinking if I ran the car with it jacked up then it would try to lower the car. If it couldn't because it was jacked up then what would happen? Haven't checked for leaks and not sure if compressor comes on. I will check on the rear when raising and lowering as well.

Last edited by hippchip; 11-21-16 at 07:36 PM.
Old 11-21-16, 07:58 PM
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takimanpgt
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Originally Posted by hippchip
The second jack was the scissor jack attached just behind the front wheels. Then I put on jack stands. I will send pic in the am. The wheel is off and it's jacked up. So I was thinking if I ran the car with it jacked up then it would try to lower the car. If it couldn't because it was jacked up then what would happen? Haven't checked for leaks and not sure if compressor comes on. I will check on the rear when raising and lowering as well.
Thanks. In sequence:

- take pics
- check again to see if you per chance moved or disconnected the linkage in any way
- put wheels back on
- lower and remove jack
- measure the height from ground to side skirt as a before.

Then test the air. Lower it completely, measure your heights. Raise and measure again. All 4 corners.

If you tried working the compressor without lowering the car completely to the ground, you are brain tired. The LCAs need to be loaded re: car on ground before the ECU works the air into the bags. Otherwise, how do you expect the ECU to know what the suspension level is?
Old 11-22-16, 01:37 AM
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hippchip
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What I meant was I ran the car to test the rack with it jacked up in the air. Would that cause problems for the leveling system?

Last edited by hippchip; 11-22-16 at 03:55 AM.
Old 11-22-16, 04:03 AM
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hippchip
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rkw, did you remove the drawings?


Originally Posted by rkw77080
The sensor is electrical. It translate the linkage position, which is attached to the lower control arm, how high the vehicle is sitting. So if the linkage is detached, the sensor will "think" that your car is sitting too high and open the air valve to try to lower the car.
Old 11-22-16, 04:03 AM
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rkw77080
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Yes, I did. You've confirmed that the height sensor was not the culprit.

Running the car while the wheels are off the ground was your problem - the ECU was confused. Take a look at Post #4 on the link below for a fix:

https://www.clublexus.com/forums/ls-...lt-change.html

The person mentioned that he got his car back to normal height in 2 steps. He disconnected the negative cable from the battery for some time, and reconnect and the air suspension came up to 17" (measured from the ground to the silver strip on the front bumper). He disconnected the battery again, reconnect, and the second reset got the car up to 21.5". I suspect the second "disconnect" was not necessary. The compressor has an over-heat protection and I think it shut off when the car reached 17".

With the car sitting without a jack, I suggest disconnecting the battery for a few minutes. Meanwhile measure the height for later reference. Reconnect and run the car for 2 minutes. Re-measure the height and allow the compressor to cool for 10 minutes. Repeat this process (run no more than 2 minutes, then allow 10 minutes cooling) until your car reaches the proper height.

Good luck!

Last edited by rkw77080; 11-22-16 at 04:23 AM.


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