AHC, Actual Height, Pressures - LC100 (1 Viewer)

[ramangain]

Hi Azi,

Yikes! That isn't Photoshopped, is it?

You can bleed/purge the AHC without using new fluid. You just recycle the existing fluid back into the resevoir to chase out air methodically. Back left, back, right, accumulator, front left, front right. After each one put the fluid back in the resevoir. After purging the truck should go into slammed stance and be super bouncy when sitting in the truck and shaking around in the seat. Ensure your resevoir is super full before repriming the AHC system. Do this process twice. You should have a minimum level of fluid at the MAX line in L before you go to the N position in the ride height, then go for a drive. I'm crossing my fingers for you. Don't go to H unless you are at the MIN level in N or you may suck air into the pump, and all of this work may need to be repeated. 10mm wrench, 3/16" tubing, and a clean fluid catch are needed. Pull the nipple covers off completely so the tubing fits on the nipple securely. Drain each spot until no more fluid comes out. Best of luck.

 

[ramangain]

NVM, see above

 

[uHu]

Re further bleeding: When your graduations-count between Lo and Hi is as low as it is, there isn't much chance of there being much air or foam in the fluid, as that would give a higher fluid compression (and draw more from the reservoir) when the pressure goes up as much as it does when moving from Lo to Hi.

Bad spheres don't give any fault codes. Bad height sensors don't normally give fault codes either. You really need to check those sensors. Your current state (stinkbug) indicates at least one bad sensor (or link, or cabling/plug),/ not necessarily the rear one, but likely.

The cost of spheres from partsouq, isn't that for a pair? I.e. divide by 2 ?

 

[Azi]

Thank you @ramangain for sharing the method. It will come handy at a certain point, I am sure!
For now, I will not touch it and start with the sensors first - just ordered a new one for the rear.

@uHu, I was thinking about that too - being a pair, but the website doesn't say a thing about a pair.
There is even a mark (FR - front right I guess) on the photo of 49141-60010 E.g.

Meanwhile, I received a reply from Amayama:

Japanese Customs does not allow flammable, high pressure or prohibited items such as accumulators, airbags or gas generated seat belt pretensioners to be sent by any form of shipping from Japan without an MSDS document (data sheet from the manufacturer outlining safety procedures for the product) which the manufacturer has refused to provide to us, so I'm afraid we cannot supply it.

Apologies for the inconvenience.

Looks like that they will not ship the spheres...

Facing the facts, I left with the options:
a) eBay
b) Pleiades

 

[J1000]

The latest photo is how you "found" the vehicle meaning after sitting for several hours/days? If so then I would not suspect the sensors because the vehicle was switched off and should have maintained pressure and the height it was left at. Looks like yours bled down over a period of time. If it's not leaking onto the ground, then I would suspect an internal leak past some seals in the system.

If I were in your situation I would replace the AHC pump and associated seals. Your symptoms sound like a failing AHC pump which was making low pressure so the T-bars were cranked as much as possible resulting in a bouncing ride after hitting bumps but front pressures are in spec. Combined with low pressure the pump could be leaking pressure internally when parked.

 

[Azi]

@J1000 not really.
I started the car and it automatically went up in the rear and indicate "Lo" on the dash. The car is going up and down very fast without any noise coming from the pump, so I believe it operates well. The only time I could barely hear the pump is when I turn off the car and pull out the key from the ignition. Some buzzing noise is coming from where the AHC reservoir is - behind the dash/glove box.

However, today I followed @uHu 's instructions on cleaning the rear height control sensor and I was shocked by the dirt I found inside.
I went through some photos here on the forum with some really dirty sensors, but I do believe that mine beats them all.

Attaching a few photos of what I found inside:

So far so good - the car went back to its normal height and indicates "N" on the dash. Height Control is also working again.
Unfortunately, the 2CM difference at the back is still there...52cm @DS and 54cm at the passenger side.

 

[Azi]

A tiny update.
Finally, the rear linkage and new sensor arrived and I installed them.

The situation at the back is still the same - got a few cms difference left to right.
FL: 50cm
FR: 50cm
RL: 52cm
RR: 55cm

Can I get your assistance @uHu once again, please?

Thank you in advance!

 

[ramangain]

I'd suggest loading a couple hundred pounds centered in the trunk and measuring again. Then add some more weight and re-measure. Don't turn the truck on; you don't want the AHC operating to compensate for anything. See if that 3cm difference is constant or not. If constant, look at things that don't compress on each rear side and compare. If not constant, look at things that do compress on each rear side and compare. Eliminate the non-AHC variables....

 

[rekab6969]

Azi, I feel your pain, I am having similar problems, your thread and all the great information the guys are giving you has given me loads to work with / check tomorrow.

a BIG THANK YOU to all.

db.

 

[rekab6969]

Would anyone know the bleed nipple size / thread etc as mine have been rounded off so I would like to replace them..?

AHC working fine now thanks to one and all, rear sensor had a bent linkage so really messed things up.

Never got any fluid from the accumulator though...??

New rear shocks installed too..

Thanks again..

db.

 

[IndroCruise]

Would anyone know the bleed nipple size / thread etc as mine have been rounded off so I would like to replace them..?

AHC working fine now thanks to one and all, rear sensor had a bent linkage so really messed things up.

Never got any fluid from the accumulator though...??

New rear shocks installed too..

Thanks again..

db.

Unable to help with nipple size / thread etc but here are the part numbers:

 

[uHu]

M7 thread, 10mm spanner.