replacing AHC globes/accumulators (1 Viewer)

[LXKevin]

Not sure if you're kidding or not, but I don't think 8.0 with temp sensor disconnected would yield significant harshness. I can say that from a theoretical standpoint and first hand experience. Provided no change to height sensors, the system spring rate is roughly the same whether you get it from the AHC hydraulics or the mechanical springs.

My car was 7.9 with sensor disconnected when I bought it. Ride quality was still great. I would argue ride quality is degraded now that I'm below pressure spec.

Regarding bleeding, he didn't bleed the height accumulator. That's fine. The manual calls for bleeding of the 4 actuators. He did bleed (so I've been led to understand) all 4 actuators. The chances of air getting trapped in the height accumulator when that bleeder was left alone seems very low. Therefore, bleeding of height accumulator seems like a low risk - even the correct approach if you believe the formal manual. I would bleed the accumulator, but by no means does it seem to be required.

I best be getting back to that gate now...

 

[Joshuak172]

Not sure if you're kidding or not, but I don't think 8.0 with temp sensor disconnected would yield significant harshness. I can say that from a theoretical standpoint and first hand experience. Provided no change to height sensors, the system spring rate is roughly the same whether you get it from the AHC hydraulics or the mechanical springs.

My car was 7.9 with sensor disconnected when I bought it. Ride quality was still great. I would argue ride quality is degraded now that I'm below pressure spec.

Regarding bleeding, he didn't bleed the height accumulator. That's fine. The manual calls for bleeding of the 4 actuators. He did bleed (so I've been led to understand) all 4 actuators. The chances of air getting trapped in the height accumulator when that bleeder was left alone seems very low. Therefore, bleeding of height accumulator seems like a low risk - even the correct approach if you believe the formal manual. I would bleed the accumulator, but by no means does it seem to be required.

I best be getting back to that gate now...

So, I was going through the steps and got the following readings from my height control sensors at neutral: it looks like my rear left isn’t measuring a change in height at all. Could this be a reason for my suboptimal ride?

 

[tjb]

So, I was going through the steps and got the following readings from my height control sensors at neutral: it looks like my rear left isn’t measuring a change in height at all. Could this be a reason for my suboptimal ride?

There’s only one rear sensor - it shows up as the right rear on Techstream. Perhaps the 0.0 reading on left rear is because there is a placeholder for it in your software?

 

[Joshuak172]

There’s only one rear sensor - it shows up as the right rear on Techstream. Perhaps the 0.0 reading on left rear is because there is a placeholder for it in your software?

Ok this makes more sense. I appreciate your help.

 

[suprarx7nut]

So, I was going through the steps and got the following readings from my height control sensors at neutral: it looks like my rear left isn’t measuring a change in height at all. Could this be a reason for my suboptimal ride?View attachment 2575190

Looks like right front sensor is low. Same with rear. If you get those readings consistently, it's probably worth adjusting the sensors based on manual measurements.

You definitely need a spacer or heavier springs to get that rear pressure down.

I'm unsure if either will alter ride quality.

 

[J1000]

Tell me if the symptoms I am having are what you experienced before you swapped the globes and if it was improved after.

Lately, it feels like every little bump causes a jarring sensation in the vehicle. Big speed bumps are OK, but little cracks in the road are very pronounced. I don't know how much of this the globes vs the E-rated tires.

The vehicle goes up and down fine. The comfort switch works.

I get 7 marks on the test. I have bled and replaced the AHC fluid twice in the last 20k miles.

Could be your wheel bearings need to be repacked. That's what it sounds and feels like when they start to get loose.

 

[Joshuak172]

Looks like right front sensor is low. Same with rear. If you get those readings consistently, it's probably worth adjusting the sensors based on manual measurements.

You definitely need a spacer or heavier springs to get that rear pressure down.

I'm unsure if either will alter ride quality.

Well, I had a heck of a time trying to zero out the front height sensors. It seems I was chasing my tail going back and forth from front right to left. Every change I made to the right affected the left and vice versa. I finally ran out of space and just screwed both almost back to where they were originally and called it good. Still off my -7 front left and -4 front right. On the rear it seems I had no change at all in the measured value of the height sensor no matter where I moved the slider. Totally maxed it was the same value as shortened all the way. The pressure values did same to change quite a bit in the process with the front being at 5.4. A few turns counter clockwise and the recorded value is back on spec. After all this my height sensors are still not zeroed out and the ride seems noticeably worse. Really getting frustrated at this point and about ready to throw on the towel. Someone talk me off the ledge?

 

[AFei]

Just received 4 new globes from Impex in Japan, $636.81 for the globes, $89.37 for the shipping, $726.18 all in.

Took 14 days from the order to Fedex pulling into a driveway where I am doing the work in North Carolina.

I'm trying to order from Impex too, and thank you for sharing the experience. Did FedEx give you any hard time on Custom Duty?

 

[tjb]

I'm trying to order from Impex too, and thank you for sharing the experience. Did FedEx give you any hard time on Custom Duty?

No. I’ve ordered from Amayama Japan and somewhere in the Middle East, too, and never had any issue with customs. I wasn’t trying to duck it, just never had the issue raised.

 

[AFei]

Well, this really made my day. Got the last one off this morning.

Graduations test now at 15 (at least), all the looseness in the car handling is gone, and unexpectedly, my rear end is now in sync - the driver's side had been lower.

Job was not that hard (for an obvious beginner). Toughest part was getting the new globes into the threads.

Sorry for keeping asking you but since you have the most refreshed experience, would you please show a picture how to use the chisel to loose the globe? Never done such thing before and worried I may penetrate the globe and cause some unexpected reaction as it contain high pressure air. Thanks!

 

[tjb]

Sorry for keeping asking you but since you have the most refreshed experience, would you please show a picture how to use the chisel to loose the globe? Never done such thing before and worried I may penetrate the globe and cause some unexpected reaction as it contain high pressure air. Thanks!

I’m back in frigid Maine after doing the work in a climate controlled garage in North Carolina, so it’s not practical for me to get a photo.

I used a wood chisel (the wrong tool - no one will be using it as a wood chisel ever again) but its length was right and I had a good chance of actually hitting the handle with the hammer. (One fingernail is still black and blue these months later from this job. )

It really was as simple as placing it against the fattest part of the globe with an angle that would push the globe in the right direction, and hammering it like hell. If I recall correctly, I did get some purchase with a small indentation in the globe caused by the chisel, but the walls of the globe seemed so thick that I never thought that piercing it was the slightest risk.

It took some hammering, though. It wasn’t like one or two blows and it was spinning free. At that point, it was the only way it was coming off, so I kept at it probably much longer than I would have had it been the first thing I tried.

 

[flintknapper]

Sorry for keeping asking you but since you have the most refreshed experience, would you please show a picture how to use the chisel to loose the globe? Never done such thing before and worried I may penetrate the globe and cause some unexpected reaction as it contain high pressure air. Thanks!

The walls of the globes are exceedingly thick, you aren't going to pierce them unless you keep hammering in the same spot long enough to recreate Mount Rushmore.

 

[AFei]

Thank everyone's response. Now I'm more confident I can get it done!

Just placed my order on IMPEX, and looks like JPY is down a little bit, and all 4 globes including their tax costs me $627.38. Wish I have ordered in Dec 2020 when couple credit cards ran 5% rebate for PayPal.

Speaking of PayPal, pay attention to their exchange rate, I just found I paid $20 more by letting PayPal exchange JPY to USD for me. Some credit cards don't overcharge rate or fee for international transaction, and you may want to change to let PayPal to bill your credit card directly in JPY instead of USD to save $20.

 

[tjb]

Speaking of PayPal, pay attention to their exchange rate, I just found I paid $20 more by letting PayPal exchange JPY to USD for me.

This is a scam that banks run across the world, too. When at an ATM while traveling abroad, never let the bank do the conversion for you. The ATM cards are backed by the big credit card companies, which provide close to the interbank rate - as close as your going to get.

 

[AFei]

This is a scam that banks run across the world, too. When at an ATM while traveling abroad, never let the bank do the conversion for you. The ATM cards are backed by the big credit card companies, which provide close to the interbank rate - as close as your going to get.

Exactly, when I travelled to Europe and Asia, I always had to pay special attention to change the billing currency back to local currency, instead of USD, on every single ATM and every single credit card transaction. TL;DR: Only pay local currency, and never pay USD.

 

[AFei]

but I don't think 8.0 with temp sensor disconnected would yield significant harshness

I knew it must have been discussed somewhere, and there does exists an over 40 pages of "Definitive list of AHC maintenance items". However, I'm struggling to read through all those posts to summary the correct way to use TechStream to measure AHC. Is it supposed to disconnect the temp sensor somewhere for the correct reading? Highly appreciate if anyone can point me to the right post...

I tried to read the pressure last night, and seemed could only read the pressure for "H" and "N". There was no reading (0) when at "L", or the pressure reading just stay unchanged when going from "N" to "L". Is this expected?

It seems my pressure was extremely high? Will the new globes relief the high pressure? Or I also need the new T.B., and/or Spring/Spacer?
====> "H" <====

====> "N" <====

====> "L" <====

 

[suprarx7nut]

I knew it must have been discussed somewhere, and there does exists an over 40 pages of "Definitive list of AHC maintenance items". However, I'm struggling to read through all those posts to summary the correct way to use TechStream to measure AHC. Is it supposed to disconnect the temp sensor somewhere for the correct reading? Highly appreciate if anyone can point me to the right post...

I tried to read the pressure last night, and seemed could only read the pressure for "H" and "N". There was no reading (0) when at "L", or the pressure reading just stay unchanged when going from "N" to "L". Is this expected?

It seems my pressure was extremely high? Will the new globes relief the high pressure? Or I also need the new T.B., and/or Spring/Spacer?
====> "H" <====
View attachment 2578564
====> "N" <====
View attachment 2578565
====> "L" <====
View attachment 2578566

Pressure readings are only really valuable when going from L to N.

Your pressures are a little high. Adjust the front until you hit the target (6.7 ish maybe?) And then we can discuss rear options.

 

[AFei]

Great to know. Will try and report back...
Thanks!

 

[AFei]

Hi @suprarx7nut , just finish watching your wonderful video, and got very detail info including cheat sheet. Super helpful! Thanks for the excellent work!

 

[flintknapper]

I need to attend to my AHC pretty soon too. Thought I'd play with my TYT II a little and see what it will scan/read on the AHC since I didn't want to fool with techstream. It showed a code (pump pressure out of spec). Then I was able to access my pressure readings and not surprisingly I am a bit out of whack. So I need to order new rear springs, new globes all around and go to work.....I suppose.

I apologize for the poor photos (glare on the screen), the sun was shining right into the vehicle.