Hello!

My LR3 is having the common issue of lowering down to the bump stops after having been parked for several days. I understand the vehicle will wake up 2 hours after the ignition is turned off to re level the vehicle if it is not within spec.

When I start up the vehicle, the compressor runs for a few minutes and does it's self leveling routine and while driving it may run here and there but there are no faults.

The first thing I've done is parked the vehicle , put it into off road height, and removed the F26 EAS fuse to disable the air suspension. After leaving the vehicle sit odr a couple days, the suspension has not dropped at all.

I'm thinking there are no leaks in the system, at least not going to the individual air bags. Would this mean that my ride Height sensors should be calibrated? While hooked up to the IID Gap tool, I'll get 2 of the sensors alternating between values but only by 1 mm or so, and they 4 corners are not equal. The parking lot I'm in is sloped in 2 directions though so that's probably why.



Any other suggestions as to what I should troubleshoot?

Thanks!!

 

I don't get why people raise to off-road. Stupidest advice people given out when it comes to diagnosing EAS. (I am not picking on you, just the idiots that say to do that) Park it like you normally would, which I assume is standard height and try again. This is because the air struts have air bags but they are not big fluffy pillows like one might see on large equipment. Ours are part of the strut and are wrapped around it. So the shape of the air bag is more like a a tall very skinny doughnut. And therefore is has a fairly sharp bend at the bottom and the outside skirt of the airbag folds and heads back up to the top. A cross section would be a tall U shape. And at the bottom of that U cracks often form because at normal height it is always bent/curved there. Also that curved part is more exposed to elements. But if you put it in off road height, that normally folded spot is pulled up higher into the strut and those likely cracks that are leaking are now sealed up in two ways. The rubber is now pressing against the aluminum "hull" of the strut and those cracks are no longer "fanned" out so to speak, so they are closed up.

So you always want to do the test at normal hight if that is the height its set at and when it usually leaks down. And yes, you have leaks. No doubt. It would be the only reason for it to drop. The system does "level" at two hours but also it does so every six hours after that. But keep in mind it is not leveling like it does when its running. It only levels to average things out. It does not raise, ever, when in sleep mode. It can only lower. It will not run the compressor or take air from the reservoir (because it can never know how much air is stored in there). So lets say you have a leak up front and as the night goes on the front starts the drop. When a self level when sleep event comes on, it will lower the rear to match the front. In theory the best way to know which end is leaking is to check on the vehicle before the two hour mark and again before the six hour mark (FYI, the shop manual is not clear if that six hours starts after the first two hours or at shutdown). Do not unlock/start or anything during that time. But if you can catch it with one end up then you know where to look. Its not common for both front and rear to both leak. Also of course you may have only one strut leaking but the other strut on the other side has to take up that extra weight and it will lower too.

And how struts leak... I explained the fold cracks but you can very easily have a leak at a valve block of one or more struts. This is often due to contaminants on the o-rings in the valve blocks cause by air compressor desiccant dust. There is a proper method to resolving this issue.

 

Hi Dakota,

Thanks for the very detailed explanation! Your explanation about how the cracks can be sealed when in off road Height makes a lot of sense.

I'll redo my troubleshooting in standard height mode as you described and take my wheel heights measurements to see which are dropping.
It is possible it's a valve block because I got a C112F-72 (air suspension actuator stick open) fault when I went off roading. It's possible the desiccant dust is occasionally causing the valves to stick. I've seen a lot of videos and forum posts about how to rebuild the valve block should it that be the issue.

Thanks again!

 

C112F-72 could indeed be a valve block. If they stick it often means the solenoid inside is failing and rebuilding may not help. Might need a new block. Front and rear are not interchangeable even though they look it. You can try rebuilding, but if its a dryer desiccant issue then you need to address that first. After that wait a couple/few weeks for any remaining dust to get through the block then rebuild them. Otherwise you will be in the same spot very quickly.