Builds The Story of Blue (1 Viewer)

[ClassyJalopy]

Sounds like you probably have a worn out globe with a pinhole leak. Quick and easy fix. New globe and off you go.

Have you done the quick and easy pressure check and adjust? How many grads are you getting from L to H?

Load limit of AHC? Pssh, not a chance. That's not really a thing. Just like normal suspension, you update the mechanical spring components as you increase weight and AHC continues to provide the same level of support and function it always did. You can't go beyond the "limit" of AHC, but you can fail to update the conventional side of the equation. That's not an AHC problem so much as a normal suspension problem.

Thanks for reply. I have almost 13 graduations from L to H, the pressures are 6.8 front, 6.2 rear. I did put brand new globes in 2021 (roughly 25k mile ago!).
Could this be just a bad batch of globes? Should I plan on new set of globes every couple of years?

 

[suprarx7nut]

Thanks for reply. I have almost 13 graduations from L to H, the pressures are 6.8 front, 6.2 rear. I did put brand new globes in 2021 (roughly 25k mile ago!).
Could this be just a bad batch of globes? Should I plan on new set of globes every couple of years?

Hmm, that is strange. Pressures look good. Globe volume displacement is good.

If you have 13 grads I doubt you have a bad globe, but I suppose it's possible.

Thanks for copying over the pressures/grads/timeline. I didn't bother to check your previous post - my bad!

I would bleed again after some time and see if the rear is still bubbly on both sides. The height accumulator could burst as well so that's something to consider.

I think a faulty rear sensor would make for a very bumpy ride, but I would expect that to result in a code.

I wish I could interact with a troublesome AHC vehicle like this. Every one that rolls through the ADGU shop seems to be a super simple fix or the common wiring degradation from the rear driver quarter up to the accumulator solenoid.

 

[ClassyJalopy]

Hmm, that is strange. Pressures look good. Globe volume displacement is good.

If you have 13 grads I doubt you have a bad globe, but I suppose it's possible.

Thanks for copying over the pressures/grads/timeline. I didn't bother to check your previous post - my bad!

I would bleed again after some time and see if the rear is still bubbly on both sides. The height accumulator could burst as well so that's something to consider.

I think a faulty rear sensor would make for a very bumpy ride, but I would expect that to result in a code.

I wish I could interact with a troublesome AHC vehicle like this. Every one that rolls through the ADGU shop seems to be a super simple fix or the common wiring degradation from the rear driver quarter up to the accumulator solenoid.

Oh, also, the rear height sensor is brand spanking new abt 25k miles ago as well. And the AHC pump was also new Toyota unit at the same time.
Probably not as relevant, but I did replace all bushings (top and bottom) on both front and rear hydraulic rams/shocks.

When you say height accumulator, is it the thingumajig that the globe screws into? Or is the long bottle shaped whatchamacallit that is nearly on the center of driver side frame rail?

 

[ClassyJalopy]

Went back and flushed both rear again until there were no more air bubbles left. Took about 0.75L of fluid.
Checked the heights: FR 19.75", FL 19.75", RR 20.75"
Rides as bumpy as before!
Other data points below:

 

[suprarx7nut]

Oh, also, the rear height sensor is brand spanking new abt 25k miles ago as well. And the AHC pump was also new Toyota unit at the same time.
Probably not as relevant, but I did replace all bushings (top and bottom) on both front and rear hydraulic rams/shocks.

When you say height accumulator, is it the thingumajig that the globe screws into? Or is the long bottle shaped whatchamacallit that is nearly on the center of driver side frame rail?

The height accumulator is the long cylinder under the driver side. It's kind of like a globe except it's not used for damping but rather storing hydraulic pressure to make raising faster. It's pressurized gas and could be leaking gas into your fluid.

I'm not sure what the average lifespan of that accumulator is, but my impression is that they don't go bad very often. While it's a similar mechanical component to a globe, I think it sees far far less stress.

If you keep seeing bubbles upon bleeding, that tells me you've got a globe with an unusual young life failure or perhaps that height accumulator is failing.

If you bleed only the height accumulator do you get much gas coming out?

 

[ClassyJalopy]

The height accumulator is the long cylinder under the driver side. It's kind of like a globe except it's not used for damping but rather storing hydraulic pressure to make raising faster. It's pressurized gas and could be leaking gas into your fluid.

I'm not sure what the average lifespan of that accumulator is, but my impression is that they don't go bad very often. While it's a similar mechanical component to a globe, I think it sees far far less stress.

If you keep seeing bubbles upon bleeding, that tells me you've got a globe with an unusual young life failure or perhaps that height accumulator is failing.

If you bleed only the height accumulator do you get much gas coming out?

Thanks for the clarification
I did blead the height accumulator before bleeding the rear and got no air bubbles at all .
So it does seem rear globe? Is there a physical way to tell if they are bad? Should I take then off and try the pencil test?

 

[suprarx7nut]

Thanks for the clarification
I did blead the height accumulator before bleeding the rear and got no air bubbles at all .
So it does seem rear globe? Is there a physical way to tell if they are bad? Should I take then off and try the pencil test?

It sounds more like a solenoid than globe, but it's hard to say from afar.

Can you do the 16-step test? You should see 4 corners with variable damping as you go through the test. I wonder if you've got one circuit that's not playing nice and maybe that will reveal it.

With the car on and sitting in park, can you jump on each corner and notice any difference in damping between corners?

 

[suprarx7nut]

Sorry, I failed to answer the pencil test part of the question. I believe the short answer is no. Pencil test helps with a completely obliterated zero pressure globe. It doesn't help with a slow leak because the membrane is still intact and hard - even if it's lost some gas.

 

[ClassyJalopy]

It sounds more like a solenoid than globe, but it's hard to say from afar.

Can you do the 16-step test? You should see 4 corners with variable damping as you go through the test. I wonder if you've got one circuit that's not playing nice and maybe that will reveal it.

With the car on and sitting in park, can you jump on each corner and notice any difference in damping between corners?

I will try jumping on each corner and report back. I will also search for the 16 step test to see of I could do it at home

 

[ClassyJalopy]

@suprarx7nut i couldn't find the 16 step test procedure despite searching for it here, any pointers you could share would be appreciated.

Also, I got up and tried jump on each corner. The fronts are pretty solid, rear both sides seem to jump almost equally, perhaps the driver side a tad bit more than passenger side!

 

[suprarx7nut]

@suprarx7nut i couldn't find the 16 step test procedure despite searching for it here, any pointers you could share would be appreciated.

Also, I got up and tried jump on each corner. The fronts are pretty solid, rear both sides seem to jump almost equally, perhaps the driver side a tad bit more than passenger side!

AHC 16-Step Damper Test

Folks, Long time lurker, and I appreciate all the info. 06 LX, 143K miles. I've got a Slee AHC Override installed running on H, with 275/70s. Performed the AHC fluid flush and get 11-12 grads on the graduation test. I get DTC 1751 on the techstream, and the ride over smaller variances in the...

forum.ih8mud.com

 

[ClassyJalopy]

Putting this here so I can intelligently name AHC components when discussing this issue:

 

[YezusLX]

Dumaflagy, whatchacallit, doohickey, thingamajig, whatchahasit, and whatchahoosit (for our Canadian friends) aren't cutting it huh? I guess someone has to be technical in this group of hooligans. Thank you for carrying that burden sir!

Putting this here so I can intelligently name AHC components when discussing this issue:
View attachment 3374633

 

[ClassyJalopy]

@suprarx7nut Thank you for your help so far. I did the 16 step test this morning. Pretty straight forward - especially since I was able to see the stiffness level (step number) on techstream!
The stiffness definitely increased with each step. At step 16 (stiffest setting) there was almost no give in the front suspension. Rear, on the other hand, was as loose as ever! I couldn't feel any difference in the bumpiness at any stiffness level!!
I must clarify, the rear seems to ride ok on very small bumps but on larger bumps the suspension moves up and down 2-3 times after the bump, almost uncontrollably!

For extra confirmation: At level 16, I drove the front wheels up the curb (about 6-8" high) and then backed off so that both wheels would come down at the same time. Front was dead steady, no secondary up and down movements!
Tried the same thing with rear wheels - the rear jumped up and down at least 3 times before stabilizing!
Tried each rear wheel separately (up and down the curb) and both seemed to jump the same amount - although it is a little harder to tell with the rear due to the solid axle!

So what did we learn now? In a conventional suspension set up this kind of uncontrolled motion would be indicative of either blown rear shocks or the rear being over-sprung. I checked the rear pressure again, and it is right at 6.6 so it can't be the issue with rear springs.

Does this confirm the rear globes are kaput?

 

[ClassyJalopy]

Since failing of globes with just 25k miles or so is a very hard pill to swallow. Some folks have been running the same globes of 100k miles with no issues!

Is there any other possibility at all? I'd hate to spend nearly $300 on new rear globes and find out that it doesn't solve anything!

I don't have any error codes but could this be something worth looking into: MY06LX EWD needed badly - https://forum.ih8mud.com/threads/my06lx-ewd-needed-badly.1067265/post-11762758

 

[ClassyJalopy]

I checked as much AHC wiring as I could and did not see any obvious issues with any of the connectors. I even cut off a 2" wide slice from the rear passenger inner fender/wheel well to see if my wiring is compromised as reported by a couple of other forum members here: MY06LX EWD needed badly - https://forum.ih8mud.com/threads/my06lx-ewd-needed-badly.1067265/post-11762758

Well - all of that looks pretty solid as well. I am not sure if there is anything else left to check for AHC. Now I am really trying to work out if I should buy a couple of rear globes at about $300/paid or should I just bite the bullet and convert to a conventional setup ($2000 for decent aftermarket stuff!).

 

[js47]

I checked as much AHC wiring as I could and did not see any obvious issues with any of the connectors. I even cut off a 2" wide slice from the rear passenger inner fender/wheel well to see if my wiring is compromised as reported by a couple of other forum members here: MY06LX EWD needed badly - https://forum.ih8mud.com/threads/my06lx-ewd-needed-badly.1067265/post-11762758

Well - all of that looks pretty solid as well. I am not sure if there is anything else left to check for AHC. Now I am really trying to work out if I should buy a couple of rear globes at about $300/paid or should I just bite the bullet and convert to a conventional setup ($2000 for decent aftermarket stuff!).

View attachment 3377149View attachment 3377150

You know I love AHC and I know you do too, Classy! My opinion would be that $300 is a small price to pay to try and save such a brilliant system (obviously try do what you can to make sure that new globes are actually necessary first, which I think you are already doing). If the new globes don’t fix it then your decent aftermarket suspension only increased in cost by 15%.

 

[suprarx7nut]

Forgive my laziness, but what rear springs are you running? Any sensor lift?

Both rear sides feeling under damped makes me think it's a system wide issue more than bad globes.

 

[ClassyJalopy]

Forgive my laziness, but what rear springs are you running? Any sensor lift?

Both rear sides feeling under damped makes me think it's a system wide issue more than bad globes.

I am running non-AHC regular Land Cruiser springs. No lift at all.

 

[suprarx7nut]

I am running non-AHC regular Land Cruiser springs. No lift at all.

Hmm, perhaps you're oversprung? Does it go into low ok? What's pressure when you put it in high?