Leaking shock absorber and AHC malfunctioning (1 Viewer)

[Wube]

Hello there, Wube from Ethiopia.
I am new to this group and happy to join you.
I own a very well kept j100 Landcruiser, 1HDFTE motor , 2004 model. I do everything my self on this car ...don't trust anyone here in Ethiopia touching it.
My question here is, can I only change the leaking one or have to do all four together? I have all new in store also the fluid 2l I have in my garage at home.
How often fluid shall be changed? The one inside is almost 7 years inside.
Never had issues with AHC till yesterday where it lost control in the back and pushed all the way up and not coming to level . I noticed the leak and added few fluid, then now all becomes good again. But need your suggestions for better care.
Cheers, Wube

 

[delz05]

Love that shade of green! Yes, you can replace the just the leaking shock, but double check it is the shock and not the fluid line that attaches to the top of the shock. A bit more investigation is required. Good luck!

 

[suprarx7nut]

Check neutral pressures first. Do not replace the shock before checking pressures.

If you are over-pressure, the shocks can leak. The shock might be ok, it's just over-pressure.

The Toyota manual even states that "weeping" AHC shocks/rams are normal and OK.

 

[YotaWagon]

Check neutral pressures first. Do not replace the shock before checking pressures.

If you are over-pressure, the shocks can leak. The shock might be ok, it's just over-pressure.

The Toyota manual even states that "weeping" AHC shocks/rams are normal and OK.

Ugh the amount of times I've been advised that my shocks are leaking and need to be replaced. I swear you have to be an expert to not be taken for a ride, intentional or not.

 

[Wube]

Check neutral pressures first. Do not replace the shock before checking pressures.

If you are over-pressure, the shocks can leak. The shock might be ok, it's just over-pressure.

The Toyota manual even states that "weeping" AHC shocks/rams are normal and OK.

Thanks, But how do I check the neutral pressure? Soon when I started engine rare side goes to very high and front side too low . I would say High in rare and Low in the front . The dashboard signs on L ...so badly bouncing also. Need help

 

[David310]

You need Techstream software and a laptop with a specific USB to OBDII connector to check pressures.

How-To: TechStream In 5 Minutes

Getting Techstream up and running can be a bit of a pain. Hopefully this helps someone get started quickly. Step 1: Purchase an OBD-II / Mini-VCI interface. - I have sold out of my cables and supply chains are back in order, so no reason to purchase more. Anything like this will work: Mini-VCI...

forum.ih8mud.com

Also watch YotaMD's video:

Weeping shocks can be due to over pressure but a little bit is normal if pressures are all in line.

 

[IndroCruise]

Soon when I started engine rare side goes to very high and front side too low . I would say High in rare and Low in the front . The dashboard signs on L ...so badly bouncing also.

As already explained by others, there is no point in changing out 'shock absorbers' before testing Front and Rear AHC pressures and bringing them into the correct range specified in the Factory Service Manual (FSM). This requires Techstream or other scanner capable of reading the Suspension Electronic Control Unit (ECU). Correction of the Front and Rear AHC pressures may eliminate or at least minimise the leaks. It also is important for the correct operation of the suspension for the Front and Rear AHC pressures to be kept in the correct ranges.

The description of the erratic Front and Rear height behaviour suggests problems with Height Control Sensors -- and this may mean that the Suspension ECU has placed the AHC and TEMS systems in "fail safe function". In this case, AHC and TEMS functions are prohibited and the ride will seem rough. Again, this requires Techstream or other scanner capable of reading the Suspension Electronic ECU to reveal the Diagnostic Trouble Codes (DTC's).

Even without the DTC's and without Techstream or other scanner, the Height Control Sensors can be removed from the vehicle and tested as set out in the FSM -- see extract attached -- and the Height Control Sensors also can be opened and inspected internally. It seems likely that testing will suggest replacement of at least one of the three Height Control Sensors -- there are two in the Front and one at the Rear. There are many posts about Height Control Sensors on IH8MUD.

If you need some notes and links to the AHC sections of the Factory Service Manual (FSM), these can be found at the link below. The AHC and TEMS systems are the same for LX470 and LC100 (where fitted):

Ahc 2006 LX470 leak.

I’ve replaced a couple corroded lines a few years ago and I have a new leak. It’s inboard of the accumulated on the left side. There’s a stain on the driveway and I can see where it’s wet visually. The problem is I can’t reproduce it on demand. The height control works but it doesn’t leak...

forum.ih8mud.com

 

[AtinLango]

Ugh the amount of times I've been advised that my shocks are leaking and need to be replaced. I swear you have to be an expert to not be taken for a ride, intentional or not.

When I was still a novice with AHC, every mechanic here wanted me to change my "shocks - struts" just because they were old (not even leaking). The pressure from mechanics was too much, so I allowed one of them to change all the struts. That was the beginning of problems, yet all was okay before. I wasted money to change the struts, and then more money to fix issues caused. The mechanics here do not believe (and do not know) anything technical regarding AHC - such as neutral pressures, graduation test, etc. They simply don't believe in such, yet they claim to be experts in AHC if you ask them.

Here, I am literally on my own regarding AHC. The only thing that has saved me is this Forum. Now, I do virtually everything AHC on my own. There is no mechanic here to help - they will just damage the system. I am now my own AHC expert. When I get any AHC issue, I sit down and think and read. Then I get a helper basic mechanic to give a hand in sorting the issue as I give instructions.

 

[Wube]

As already explained by others, there is no point in changing out 'shock absorbers' before testing Front and Rear AHC pressures and bringing them into the correct range specified in the Factory Service Manual (FSM). This requires Techstream or other scanner capable of reading the Suspension Electronic Control Unit (ECU). Correction of the Front and Rear AHC pressures may eliminate or at least minimise the leaks. It also is important for the correct operation of the suspension for the Front and Rear AHC pressures to be kept in the correct ranges.

The description of the erratic Front and Rear height behaviour suggests problems with Height Control Sensors -- and this may mean that the Suspension ECU has placed the AHC and TEMS systems in "fail safe function". In this case, AHC and TEMS functions are prohibited and the ride will seem rough. Again, this requires Techstream or other scanner capable of reading the Suspension Electronic ECU to reveal the Diagnostic Trouble Codes (DTC's).

Even without the DTC's and without Techstream or other scanner, the Height Control Sensors can be removed from the vehicle and tested as set out in the FSM -- see extract attached -- and the Height Control Sensors also can be opened and inspected internally. It seems likely that testing will suggest replacement of at least one of the three Height Control Sensors -- there are two in the Front and one at the Rear. There are many posts about Height Control Sensors on IH8MUD.

If you need some notes and links to the AHC sections of the Factory Service Manual (FSM), these can be found at the link below. The AHC and TEMS systems are the same for LX470 and LC100 (where fitted):

Ahc 2006 LX470 leak.

I’ve replaced a couple corroded lines a few years ago and I have a new leak. It’s inboard of the accumulated on the left side. There’s a stain on the driveway and I can see where it’s wet visually. The problem is I can’t reproduce it on demand. The height control works but it doesn’t leak...

forum.ih8mud.com

Thanks a lot dear. Sorry for disappearing, just returned from two months travel abroad.
Will work on your suggestion and update my success.
Cheers

 

[Wube]

Thanks a lot dear. Sorry for disappearing, just returned from two months travel abroad.
Will work on your suggestion and update my success.
Cheers

Hello everyone, I have great news after Long story :- ....enjoy my fairytale here !
The solution to my AHC malfunctioning is found by Changing all 3 sensors and the fault was the rare sensor which caused all the bumping and malfunctioning. The long story with the AHC malfunctioning, which took me almost a month till yesterday, is over. Now it works properly.
You know, i was quite sure that it has to do with accumulators and diagnosed it with OBD and got low pressure in the system. So i inspected all 4 accumulator globes, were good and pencil test done, were all pure and fitted them back. Then the most difficult journey started with the accumulator pump...i can't tell you all $ and energy it costed me to get new part from US to Ethiopia, big theater with border security in DC airport, they took it away on passenger flight as it has compressed gas inside and payed 1000usd Dangerous good Air cargo shipment...tax in Addis Ababa 500 usd , buying price with the sensors from toyota dealer in usa payed 2500 usd ...
Then tried to take out the old pump, that is almost IMPOSSIBLE! ...Two Bolts are under chassis where you can't access them , killing. .. that was all done and the oil line bolt rusted and damaged to gett it off, used all available Special sprays ( rust off ) didn't help and i cutted it -off and weld it back with new bolt. New pump fitted back and big surprise,... didn't work still, AHC failed to lift the front side and rare side lifted Tooooo high as the begging. Tried all to check
But finally...finally where i almost lost the hope where to get the couse , by chance I saw your video and thought let me simply change all sensors, THAT WAS IT ! YES It was the RARE Sensor it coused the problem.
Many fellow people posted only accumulators changing as solution, and I think I'm the only one who changed the Height Control Accumulator pump , which i think is built for lifetime. Wasn't necessary at all in my case to change it.
Thank you , i almost told you here all my journey with AHC researching, where i fill now I'm MASTER of it
Happy to share my experience and i will continue taking care of my bloved Iron-Model j100. ❤....and enjoying it till we both get old . Very happy after all.
Cheers!

 

[Wube]

Hello everyone, I have great news after Long story :- ....enjoy my fairytale here !
The solution to my AHC malfunctioning is found by Changing all 3 sensors and the fault was the rare sensor which caused all the bumping and malfunctioning. The long story with the AHC malfunctioning, which took me almost a month till yesterday, is over. Now it works properly.
You know, i was quite sure that it has to do with accumulators and diagnosed it with OBD and got low pressure in the system. So i inspected all 4 accumulator globes, were good and pencil test done, were all pure and fitted them back. Then the most difficult journey started with the accumulator pump...i can't tell you all $ and energy it costed me to get new part from US to Ethiopia, big theater with border security in DC airport, they took it away on passenger flight as it has compressed gas inside and payed 1000usd Dangerous good Air cargo shipment...tax in Addis Ababa 500 usd , buying price with the sensors from toyota dealer in usa payed 2500 usd ...
Then tried to take out the old pump, that is almost IMPOSSIBLE! ...Two Bolts are under chassis where you can't access them , killing. .. that was all done and the oil line bolt rusted and damaged to gett it off, used all available Special sprays ( rust off ) didn't help and i cutted it -off and weld it back with new bolt. New pump fitted back and big surprise,... didn't work still, AHC failed to lift the front side and rare side lifted Tooooo high as the begging. Tried all to check
But finally...finally where i almost lost the hope where to get the couse , by chance I saw your video and thought let me simply change all sensors, THAT WAS IT ! YES It was the RARE Sensor it coused the problem.
Many fellow people posted only accumulators changing as solution, and I think I'm the only one who changed the Height Control Accumulator pump , which i think is built for lifetime. Wasn't necessary at all in my case to change it.
Thank you , i almost told you here all my journey with AHC researching, where i fill now I'm MASTER of it
Happy to share my experience and i will continue taking care of my bloved Iron-Model j100. ❤....and enjoying it till we both get old . Very happy after all.
Cheers!

Something to add, all 4 accumulator globes are ok for now but I checked the efficiency, only 6/7 gradient difference from L to H so which means I need to invest another 1200 usd soon to have it all done .
Good day ! Love you all Cruisers !