AHC Fluid Flush How-To Video (1 Viewer)

[Lucky Strike]

Hey guys,
I put together a video on how to perform a fluid flush on the AHC system from start to finish using only 2.5L of fluid. Its a really straight forward process. If you've ever thought about doing it and weren't sure you could tackle it, hopefully the video will give you a good perspective on what is involved. If you have any questions let me know.

Parts required for this job:
(1) 2.5L can of Toyota AHC fluid - PN# 08886-01805
-OR-
(3) 1L containers of AHC fluid - PN# 08886-81221

 

[LXstatic]

Great Video!! Looks like your next job is to address the leaky cv boots... I'm doing mine this weekend myself

 

[Lucky Strike]

Thanks for the kind words. yeah ill be installing new clamps on the cv joints and cleaning them up. I did a little off roading the past two weeks.

 

[kcobourn]

Question for the group - when I did this I didn't go back to confirm no air was in the shocks. Truck drives great ... any reason why I should check if no issues?

 

[Lucky Strike]

Air can't get in the shocks if you followed how it was done in the video or similar.

If you move the truck up without sufficient fluid in the reservoir, it will suck air. sounds like you did it right.

 

[PADDO]

Question for the group - when I did this I didn't go back to confirm no air was in the shocks. Truck drives great ... any reason why I should check if no issues?

It's better practice to check all bleed points for entrained air when you do your fluid changeout. Reason being that hydraulic fluid, even the new stuff straight out of the can, contains dissolved air - up to 10% by volume in some cases - and this dissolved air comes out of solution and forms bubbles (called entrainment) over time. Temperature increases, (have you felt how hot the damper assemblies get after a bit of hard driving?) and pressure differentials when the fluid is rapidly worked back and forth through the damper orifices are the two main driving forces in the system that cause this dissolved air to come out of solution. Nitrogen that permeates across the accumulator's diaphragms also comes out of solution. When you crack the bleeders on a system that has never had a fluid change or hasn't had one in a long time you expect to get bubbles, even though the system has never drawn bulk air into itself via the reservoir.

 

[AMSarge]

Great video and help. I think I'll give this a go!

 

[OregonB]

Thanks for the video post!

 

[UTadventures]

Just completed. Excellent video. One adjustment I made was to start at P side rear 1st, then D side rear, all the way around. Thanks!

 

[Lucky Strike]

Thanks for the kind words, I'm happy that the video was able to help you guys!

 

[OEMGUY0720]

I’m about to do my AHC system a flush like this one this weekend. A few questions/clarifications:

1. It should be on LOW height setting beforeI start bleeding the nipples right next to the globes?

2. First bleed is driver side rear.
3. Second bleed is passenger side rear.
4. Third bleed is lift accumulator (driver side).
5. Fourth bleed is driver side front.
6. Last bleed is passenger side front.

7. Leave it on LOW height setting still.
8. Start engine.
9. Close all doors allow computer to repressurize all globes.

10. Put back to Neutral height setting and top up reservoir until it gets to the level between low and high level graduation marker.

Did I get the sequence right?

 

[bcngator00]

I’m about to do my AHC system a flush like this one this weekend. A few questions/clarifications:

1. It should be on LOW height setting beforeI start bleeding the nipples right next to the globes?

2. First bleed is driver side rear.
3. Second bleed is passenger side rear.
4. Third bleed is lift accumulator (driver side).
5. Fourth bleed is driver side front.
6. Last bleed is passenger side front.

7. Leave it on LOW height setting still.
8. Start engine.
9. Close all doors allow computer to repressurize all globes.

10. Put back to Neutral height setting and top up reservoir until it gets to the level between low and high level graduation marker.

Did I get the sequence right?

Your sequence sounds about right to me, but I am a noobie. This thread has a step by step PDF that you can download ( AHC Fluid Change How To -- Need Input ). I printed it out as I intend on bleeding the system and replacing with new fluid myself this weekend. The '98 LX470 that I just purchased bounces like crazy. I am hoping that a fluid replacement will help to determine the cause. I just got the TechStream cable and software to see what pressures I am getting out of the AHC system, but need to find a way to get the program onto my ancient Windows XP laptop with no CD drive. Good luck!

 

[OEMGUY0720]

Your sequence sounds about right to me, but I am a noobie. This thread has a step by step PDF that you can download ( AHC Fluid Change How To -- Need Input ). I printed it out as I intend on bleeding the system and replacing with new fluid myself this weekend. The '98 LX470 that I just purchased bounces like crazy. I am hoping that a fluid replacement will help to determine the cause. I just got the TechStream cable and software to see what pressures I am getting out of the AHC system, but need to find a way to get the program onto my ancient Windows XP laptop with no CD drive. Good luck!

Thanks for this @bcngator00 appreciate it. I just noticed that the PDF version is suggesting that for every bleed on the 5 points (accumulator and 4 globes) an engine start / 400-feet driving - this also makes sense as for the system to build up it’s operational pressure to prepare for the next actuator bleed.

I also noticed that this version of AHC flushing is suggesting to bleed the accumulator first. Thanks again will do this as soon as my AHC fluids gets delivered.

 

[Chebas]

Dear TLC fans. Thanks to this Forum I encouraged myself and jumped into an HDJ100 2006 "almost mint condition" with 106.000Km on the clock.
The 100 presented an AHC issue, too hard ride, and the previous owner left it. I have been searching at this forum and I found the way out. The accumulators were blown due to contamination. I flush the system several times. I used hidraulic oil#32, and after 4 trials with the yellow H32, I replaced the four globes (Toyota Genuines) and then flushed it twice with Toyota AHC fluid. Now it is magic carpet.

So, here we are, MANY THANKS AGAIN, i really like the way that the info is shared here.

To introduce the SUV, it´s a 2006 MY, 2006 registered HDJ100 MT with power heating, AHC, VX finish. Amazingly, no second AC for the third row, as mentioned, little bit more than 100.000Km, full service records, which was massive, and the AHC issue rose up due to "something" added to to the AHC reservoir. Seemed to be water. It´s AWD with central and rear lock diff, and obvously it´s VNT.

best and thanks,

Sebas. FRom Sebastian. Nick is Chebas.

 

[OEMGUY0720]

I hope I didn’t destroyed my AHC
1. I used a fluid extractor to remove the old AHC fluid on the reservoir (was about 1 liter of it that I took out) on LOW height mode.
2. Bled the the Globe at the front, driver side, got 1 liter.
3. Poured 1 liter of new AHC fluid onto the reservoir.
4. Turned on the engine for 30 seconds and turned it back OFF - this is the part I got confused
5. Inspected that the reservoir and saw there was no more of the new AHC fluid that I just poured, so I poured bottle #2 all 1 liter of it, then took this photo.
6. Then bled all remaining 4 spots including the accumulator and got 1 liter of old and dark brown AHC fluid.

All in all I was able to get approximately 3 liters of old AHC fluid.

Bottle #3 (1 liter hasn’t arrived yet - tomorrow it’s scheduled to be delivered by fedex.

Questions:
- is my AHC now blown?
- the current state of the AHC reservoir level is between the LOW height and the HIGH height.

**I haven’t started the engine yet since my mishap. 2nd bottle of new AHC fluid hasn’t circulated yet in the system and remains in the middle of the HIGH and LOW height level settings on the reservoir.

To be continued tomorrow..

Any helpful insights and inputs are appreciated.

 

[apdxyk]

As long as you didn't suck any air, you need to do nothing. And if you did, there is a procedure out there outlined by the most magnificent Mr PADDO, somewhere on this very forum. Nice wheels.

 

[OEMGUY0720]

As long as you didn't suck any air, you need to do nothing. And if you did, there is a procedure out there outlined by the most magnificent Mr PADDO, somewhere on this very forum. Nice wheels.

Thanks. At this point I have no idea if the lines have sucked air. I haven’t started the engine yet looks like to me the new AHC fluid hasn’t circulated inside the system yet. Looping in Mr. @PADDO on hopefully we can get his insights on what best to do next and avoid problems.