Hey all,
Looking for some insight. My 2000 LX470 is dropping the front end evenly and slowly after shutting the engine off. It takes about 30 to 45 minutes for the front to fully settle, slow enough that I can't actually see it moving. The rear stays steady the entire time.
As the front drops, the AHC fluid level in the reservoir increases. That tells me the fluid is not leaking externally. I also do not see any signs of external leaks. It seems to be flowing back into the tank. This has been happening for about a month, but the AHC fluid level has remained steady. I have not had to add more fluid.
I washed the road grime off the front struts. Both struts now look dry after sitting overnight, with no visible signs of leaking. When I start the truck, it raises back up without any trouble and rides normally. It also levels correctly while driving with no unusual behavior.
When I bought it, the front end struggled to lift. I fixed that by adjusting the torsion bars while watching the pressure in Techstream. Since then, everything has worked well while driving, but the front still settles after shutdown.
It is also intermittent. Sometimes it can sit a full 24 hours without dropping. Other times it will drop within an hour.
There are no current codes on the AHC ECU. There was an overpressure code when I first got it, but that cleared after I brought the front torsion bars into spec. The rear is still slightly over spec (less than 1.0 over, although I do not remember the exact value).
From what I have read, this could be caused by one of the following:
Things I think I have ruled out:
Has anyone seen this exact issue? If so, did replacing or rebuilding the front valve block solve it? Is there any way to confirm the valve block is the issue before replacing it?
Thanks in advance!
Standard tax:
Looking for some insight. My 2000 LX470 is dropping the front end evenly and slowly after shutting the engine off. It takes about 30 to 45 minutes for the front to fully settle, slow enough that I can't actually see it moving. The rear stays steady the entire time.
As the front drops, the AHC fluid level in the reservoir increases. That tells me the fluid is not leaking externally. I also do not see any signs of external leaks. It seems to be flowing back into the tank. This has been happening for about a month, but the AHC fluid level has remained steady. I have not had to add more fluid.
I washed the road grime off the front struts. Both struts now look dry after sitting overnight, with no visible signs of leaking. When I start the truck, it raises back up without any trouble and rides normally. It also levels correctly while driving with no unusual behavior.
When I bought it, the front end struggled to lift. I fixed that by adjusting the torsion bars while watching the pressure in Techstream. Since then, everything has worked well while driving, but the front still settles after shutdown.
It is also intermittent. Sometimes it can sit a full 24 hours without dropping. Other times it will drop within an hour.
There are no current codes on the AHC ECU. There was an overpressure code when I first got it, but that cleared after I brought the front torsion bars into spec. The rear is still slightly over spec (less than 1.0 over, although I do not remember the exact value).
From what I have read, this could be caused by one of the following:
- Internal leakage in the front valve block allowing fluid to return to the reservoir
- Worn front struts, although I would expect uneven sag, poor ride quality, or visible leaking if that were the case
- Some other factor I am not aware of
Things I think I have ruled out:
- Leaking - fluid remains steady
- Sensors - Correct me if I'm wrong, but this is ruled out by the truck being off when the issue happens
Has anyone seen this exact issue? If so, did replacing or rebuilding the front valve block solve it? Is there any way to confirm the valve block is the issue before replacing it?
Thanks in advance!
Standard tax:
