Possible AHC Height Control Accumulator Failure

[PADDO]

are they really supposed to be adjusted with standard load/on the ground?

Yes.

 

[Zer0zg]

Just a small update and call for help here. Ordered both rear AHC hoses from Cruiserparts and after two weeks with no contact they finally got back to me saying they're still trying to source one(was not clear from their website that they didn't have them in stock). If any of you happen to have spares from a conversion please let me know, trying to avoid spending 500 on a new set. Thanks!

 

[Flipped Bezel]

You may have better results going on the Classified---Parts---Axle/Suspension section and starting a wanted thread over there.

Lots of folks have replaced their AHC systems and many parts can be found in that section also if you browse through old threads there.

Good luck locating your hoses.

 

[Zer0zg]

Finally had a warm enough weekend day to do the rear AHC line... that just about kicked my ass. It’s in and everything is working well, but holy hell those bolts aren’t easy to get to. Did not drill the hole for access

 

[tjb]

Yup, use the sensor to adjust the height. Once your hub to fender is set ....

Could you explain this to a neophyte? I’m just learning about this system and gobbling up everything I can, but I got lost here. Is this essentially calibrating the sensor once the heights are correct? (And if this is correct, how does one do that? I’ve got an FSM on the way - but not here yet.)

I’m trying to grasp the whole before jumping in on anything. The guys at ACC said my rear shocks were wet but not obviously leaking, so I’m trying to plan out steps to properly diagnose/repair.

 

[trdcorolla]

Could you explain this to a neophyte? I’m just learning about this system and gobbling up everything I can, but I got lost here. Is this essentially calibrating the sensor once the heights are correct? (And if this is correct, how does one do that? I’ve got an FSM on the way - but not here yet.)

I’m trying to grasp the whole before jumping in on anything. The guys at ACC said my rear shocks were wet but not obviously leaking, so I’m trying to plan out steps to properly diagnose/repair.

You don't really calibrate the sensors. You adjust them to get the height you want. My shocks were moist. After I got the pressures in spec, they stopped seeping. You can read this thread for all the info you need:

Definitive list of AHC maintenance items

forum.ih8mud.com

 

[SARguy]

Yeah for sure! Looking at my pressures it looks like new springs are in order. Is there a cost effective option out there for new LX springs other than direct from Lexus?

When I got my 04 LX with 110K (july 2017) my AHC was working but my pressures were way off. TBs needed adjusting and the coils in back were way fatigued and too soft. I go off road a lot, drive way too fast, and like a little more stiffness, plus I tow a lot. I ended up installing Land Cruiser AHC springs, which come significantly stiffer than the LX springs. Bonus, the LC springs are a lot cheaper than the LX version. AHC pressures easily adjusted to factory spec with this setup. I have Been driving on the new springs for 30k miles now and I couldnt be happier. Even with the somewhat stiffer LC springs, the ride, on and off road, is still luxurious. If you go this route be absolutely sure not to use non AHC springs which are not compatible.

 

[tg470]

For what it's worth I just got an '03 w 180k. I had to do some work (like flushing fluid) and I have a small leak in the front right "shock". I have slightly high pressures in the rear but I'm not going to touch the springs now because next year it's AHC removal and springs will be different with off road shocks than AHC. If you can "get by" with the system working generally OK and pressures aren't too far out of spec, you might be better off not touching the system any further.

 

[Zer0zg]

Yeah, I haven't checked/adjusted my heights yet to properly check the pressures but once I do that, I have some spacers on standby to get the rear at or close to spec just in case.