.
Last edited:
AHC Fluid Change How To -- Need Input (3 Viewers)
- Thread starter ntsaint
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Hi all, new guy to the 100 series forums here.
Like an idiot i bled out to much fluid when flushing my AHC. I've got myself a lowrider now.
I can't really figure out how to get the system up and running again. I took the battery cable off, but that doesn't do a thing.
The reservoir never went dry, so that's a plus i guess.
Any tips or tricks? I've searched, but got lost in the sheer amount of information on the subject.
Some details on the Cruiser. It's a 2004 HDJ100, i'm pretty sure UZJ of HDJ have the same AHC, but just to make sure.
Thanks!
Mark
Like an idiot i bled out to much fluid when flushing my AHC. I've got myself a lowrider now.
I can't really figure out how to get the system up and running again. I took the battery cable off, but that doesn't do a thing.
The reservoir never went dry, so that's a plus i guess.
Any tips or tricks? I've searched, but got lost in the sheer amount of information on the subject.
Some details on the Cruiser. It's a 2004 HDJ100, i'm pretty sure UZJ of HDJ have the same AHC, but just to make sure.
Thanks!
Mark
I did the same thing on my 200 series about 2 years ago. I thought I had really messed it up, but it turns out I just needed to keep bleeding. You just have to keep following the bleed procedure. I had to bleed each nut like 10 times it seemed like, but eventually I got all the air worked out. Just make sure you keep fluid in the reservoir and you'll be making progress. You won't see any progress for a long time, and will almost lose hope, then eventually you'll get all the air out and it will rise like a phoenix.
Next time I do it, I will bleed less fluid off to start with
Thanks hurricane11! That's exactly what i needed to do.
I too thought i messed things up, but thankfully i didn't.
The Cruiser rides so smooth now! I love it.
I too thought i messed things up, but thankfully i didn't.
The Cruiser rides so smooth now! I love it.
how many times did you end up bleeding it?
4 times just a little did the trick. When i tried the ahc after the fourth time it slowly started working. So i let it do it's thing keeping an eye on the fluid. When it got into the hi position i dropped into lo again and cycled the suspension a couple of times. It works perfectly now.
Great! Glad I could give back to this forum!
Thanks for this man. Just ripped through this in under an hour today. Real straight forward, idiot proof, didn't drop the car on myself. 5 stars.
I see lots of and bleeding in your future to get all the air out, you might read through my thread on this.
@aharlan001
I did just that. I went thru about 12 quarts of fluid in total, both new and recycled after a while. It worked ok for a few weeks, but lately it got worse, up to a point this morning that the pump was screaming and there was no movement at all. Clearing codes did nothing, the codes came back immediately.
So thinking the pump gave up, i tore the pump assembly apart to see what's going on. I forgot to take pictures, but it was pretty nasty. I seperated the two pump halves and found that one of the strainers was completely blocked. A bit of brakecleaner and compressed air and it was clean again. Put everything together, loaded the reservoir with fluid and after a cup of coffee, started the cruiser up, cleared the codes again and the AHC came back to life. Accumulator pressure bumped up to 10.8 right away and it's quick now!
I still have to check graduations, and time how quick it is, but i was way too happy it works again and went out for a drive!
Thanks to all the usefull comments in various threads, i have a working AHC system now without spending to much money.
Mark
I did just that. I went thru about 12 quarts of fluid in total, both new and recycled after a while. It worked ok for a few weeks, but lately it got worse, up to a point this morning that the pump was screaming and there was no movement at all. Clearing codes did nothing, the codes came back immediately.
So thinking the pump gave up, i tore the pump assembly apart to see what's going on. I forgot to take pictures, but it was pretty nasty. I seperated the two pump halves and found that one of the strainers was completely blocked. A bit of brakecleaner and compressed air and it was clean again. Put everything together, loaded the reservoir with fluid and after a cup of coffee, started the cruiser up, cleared the codes again and the AHC came back to life. Accumulator pressure bumped up to 10.8 right away and it's quick now!
I still have to check graduations, and time how quick it is, but i was way too happy it works again and went out for a drive!
Thanks to all the usefull comments in various threads, i have a working AHC system now without spending to much money.
Mark
Well done @troopie!! Bleeding the system multiple times always is the best place to start -- but as you found, sometimes there is more involved and the tiny filters in the AHC Pump DO block from time time, surprising that it is not reported more often. In case it is of help to others, some pictures which illustrate similar discoveries to yours can be found at Posts #67 through to Post #70 at the thread at this link:
AHC pump out? With code 1762
I have seen 1.x was able to program key, customize telescoping, door lock, window and sunroof settings. The 1.x cable I own was able to program my key, disable my DRLs, and stop that annoying auto-telescope wheel from activating. I have a 01LX that doesn't have TPMS, and I have read multiple...
forum.ih8mud.com
Dis-assembly of the actual AHC Pump into its internal component parts is not hard -- just proceed carefully, take a few pictures as you go, there are only a few parts but they are small, only fit together one way, so keep track of what goes where, ready for re-assembly. Ideally, replace all o-rings if new can be obtained. The tiny filters could be pulled out with a pick, but can be cleaned in situ with less risk of damage by back-washing with a suitable fluid, finally use genuine AHC fluid to remove any residues of other fluids. The filters are important -- the pump gears are tiny and will not cope very well with foreign particles and sludge picked up elsewhere in the system.
I agree that I should have installed new O rings. I'll keep an eye out and might just order them and swap them anyway. I'll also flush the whole system again with fresh AHC fluid.
Can anyone confirm that the AHC procedure posted here will work with the LX570 also? I'm finding limited information on the 570 concerning the AHC flush. At least not finding specifics.
Resurrecting old thread. Anyone know a reliable place to get the AHC fluid. I’m only seeing amazon and ebay. Concerned that if it’s been discontinued this is all old stuff that’s been sitting in a warehouse for a long time. Want to do this maintenance to my new to me LX but want to do it right. Thanks.
BullElk
SILVER Star
Why is it exactly that another hydraulic fluid, and there are a few, will not work in an AHC system? Is it the glove diaphragms, the motor, small steel lines, etc. ? Why will no other fluid work sufficiently or is it the same business model of….Buy Lexus fluid from our dealership or else.. ?
I guess it’s probably how the compound conditions the rubbers and polymers in the hydraulic system, how the fluid suspends contaminants, viscosity and other related factors than CAFE / product margin type of reasons on advocating TGMO and consequently AHC oil.
It’s overall just mineral oil but the average person doesn’t know what’s in Indemitsu Kosan proprietary blend for Toyota AHC and that’s the only certified product with retail availability by far.
It’s probably a “don’t fix it if it’s ain’t broken” scenario with AHC mineral oil choice, most people aren’t risking their AHC pump, accumulator health and the cleanliness of the AHC lines with possible lengthy chemical flushes to remove sludge and perform R&R on possible AHC maintenance misadventure.
It’s overall just mineral oil but the average person doesn’t know what’s in Indemitsu Kosan proprietary blend for Toyota AHC and that’s the only certified product with retail availability by far.
It’s probably a “don’t fix it if it’s ain’t broken” scenario with AHC mineral oil choice, most people aren’t risking their AHC pump, accumulator health and the cleanliness of the AHC lines with possible lengthy chemical flushes to remove sludge and perform R&R on possible AHC maintenance misadventure.
Last edited:
PabloCruise
SILVER Star
Dealer?
My Owners Manual indicates AHC Fluid replacement at intervals of 100,000 kilometres (60,000 miles) or 60 months -- unlikely to be much different in your part of the world -- so the fluid in the vehicle should have that kind of service life [although my conservative nature would suggest change AHC Fluid every 50,000 kilometres (30,000 miles) or every three years, for good hydraulic hygiene].
The point is that if that is the service life of AHC Fluid in operation in the vehicle, then expect shelf life in good storage conditions to be much longer.
Google for "Toyota 08886-01805" or "Lexus 08886-01805" to find supplies of AHC Fluid in 2.5 litre cans -- see for example Cruiser Parts, Lexus Parts Now, Lexus Parts Depot. See also various eBay and other sources. -- look at the supplier details to check actual supplier -- for example Genuine Lexus Toyota AHC Suspension Fluid (2.5 Liters) 08886-01805 | eBay - https://www.ebay.com/itm/403649027268 means Daytona Toyota, etc, etc.
Part Number 08886-01805 refers to AHC Fluid supplied in a 2.5 litre can -- this supply seems to have a reliable record around the world. Just make sure that the seal on the lid of the can is not broken!
Part Number 08886-81221 refers to AHC Fluid supplied in a 1 litre plastic bottle -- this supply was associated with multiple reports on IH8MUD 100 series Forum and 200 series Forum and elsewhere concerning a gel substance found in the fluid in the US market in or around 2020-2021. This gel caused partial blockages at the tiny strainers inside the actual AHC Pump sub-assembly 48901-60010 and necessitated disassembly and internal cleaning of the pump and strainers or replacement of the AHC Pump sub-assembly. Suggest avoid supplies of 08886-81221 in the 1 litre plastic bottle unless folks in USA tell you that it is now reliable.
In the case of AHC Fluid, the different Part Numbers simply relate to the different packaging -- the actual AHC Fluid is the same product -- or at least it is meant to be!
Despite the bad record of 08886-81221 in USA, the actual genuine good quality Toyota/Lexus AHC Fluid is the stuff to use. Substitution must be technically possible with the relevant expertise -- but realistically nothing else is worth the risk. The additives etc used in this AHC Fluid are best matched to the Toyota/Lexus rubber and/or elastomer parts such as the membranes in the 'globes' and also this AHC Fluid is of the chosen viscosity and temperature performance matched to components in the various valve mechanisms and tiny fluid pathways in the Toyota/Lexus AHC system. For example, there are 'war stories' on threads on this Forum and elsewhere where brake fluid has been used purposefully or by mistake and the results eventually were very destructive.
Other alternatives used in active suspensions in Citroen vehicles and Mercedes Benz vehicles are claimed to be suitable -- for example RAVENOL AHC Active Height Control Fluid | RAVENOL - https://www.ravenol.de/en/product/hydraulikoel/pkw-hydraulikoel/ravenol-ahc-active-height-control-fluid -- but personally I would want to see a definitive recommendation before I departed from the genuine Toyota/Lexus stuff.
Toyota/Lexus AHC Fluid is a low volume specialist oil-based product and most likely is produced in batches in a lubricant blending plant rather than in continuous production -- so availability of supplies can be expected to be variable.
The product has not been discontinued. The same fluid is used in the AHC suspension systems in relevant LC100, LC 200, LX470, LX570 and LX600 models. It is also used in the KDSS and eKDSS systems in the LC200 and LC300 models respectively.
Last edited:
Thanks Indro. I’m not great finding or searching part numbers yet. Looked on several lexus dealer websites to try locating the fluid unsuccessfully. Appreciate you taking the time to respond.
No problem. We all learnt the same way -- by trial and error -- and I have just fixed a few typo errors in the Part Numbers quoted in my previous post!
Suggest buy two cans (5 litres) of AHC Fluid. You may not use it all -- but it is no fun starting this job and not having enough fluid. Keep any remainder for next time.
