LC100 - Help required with AHC problem

[LCFANCLUB]

Hi Everybody

Sincere thanks in advance to anyone who takes the time to read this and help out.

I live in Kenya and have an ex-japan LC100, 1999 , 190,000km, with AHC. The ride is really great but ....it has gremlins.
Recently, the AHC "OFF" light comes on and the vehicle sits at the lowest level and rides with no assistance from the hydraulics. It's basically just riding on the springs.
We found the fuse going to the AHC motor was blown, and when this was replaced everything started working as normal, the "OFF" light went away, the car rose to the normal height etc. However after a few minutes the fuse blows again and the AHC disables, the car sits on the springs etc etc.
I should mention that all 4 shocks were replaced 1,000kms ago, so it may not be a coincidence that the system has problems after the shocks were replaced (maybe the mechanic failed to carry out some reset of the system, or some other procedure that's required after the shock change?)

I am told by 2 mechanics the problem is a short within the AHC Motor and I need to replace the complete AHC Motor and Pump Assembly.

Questions :
1. Is that diagnosis correct? I would have thought that if the motor was shorted, it wouldnt work at all, but when the fuse is replaced it all works normally.
2. Can one buy the MOTOR alone, without buying the Motor AND Pump assembly. BTW - Part no for Motor and Pump is 48910-60010.
3. If the AHC MOTOR/PUMP is replaced, are there more problems round the corner with sensors etc. (as mentioned I have just replaced all 4 shocks about 1,000km ago)?
4. If the Motor and Pump Assembly does indeed need replacing, should i also put new springs at the same time? The springs have 190,000kms on not the best road surfaces!
5. Is it easier to just replace everything with a standard Toyota LC suspenison set-up (shocks, springs, torsion bars)? Is the original Toyota LC set-up the closest in terms of plushy ride to the AHC.? I would like to keep the comfort of the AHC or as close to it as possible.

Thanks again to anyone who replies.

 

[bamabrock]

Definitive list of AHC maintenance items

 

[ihadmail]

That thread has a wealth of information.

Really without techstream to read the electrical side of the problem you're grabbing at straws trying to figure out what's wrong with your system.

If they replaced the shocks and not the globe accumulators its most likely they replaced the wrong part. A quick test of the accumulators is to pull them and measure how much fluid is in each one. If it's about 25% of the volume of the accumulator you're good to go. If the accumulator is bad it will be 100% full of fluid.

Another possibility is they didn't bleed the air from the shocks properly. To bleed the system you will need 1 can of Toyota AHC fluid. Get the truck lifted into the high position of possible, turn the engine off. connect a tube from the bleeder to a can/jug of some sort and open the bleeder until fluid stops coming out. Close the bleeder. There are 4 accumulator globes on each frame rail between the body and the frame. On the driver side there is a 5th bleeder on the main pressure accumulator. If air is noticed, repeat the process of start the truck and raise it to high, turn off engine then bleed again until no air is seen. Make sure you don't let fluid reservoir run or of fluid during this process.

Hope this info helps you out.

 

[LCFANCLUB]

thanks for your advice , will try and bleed the system properly and check the accumulators

 

[PabloCruise]

Also, search for @PADDO and read everything they say about AHC...