alternative fluids for AHC system

Is Dexron VI a good substitute for AHC fluid?

  • Yes, works great for me

    Votes: 3 15.8%
  • No, causes major problems

    Votes: 11 57.9%
  • Probably

    Votes: 4 21.1%
  • There are better choices than either Dexron or Toyota AHC fluid

    Votes: 1 5.3%

  • Total voters
    19

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Pleiades suspension spheres

These are citreon c5 spheres modified to suite the land cruiser, the pressures have been altered and a adapter fitted.

I only bought them to get my originals regassed with this same company, but I have just left them on as they are good and proven to be reliable, when the time comes I will replace back to my originals.
Do you use AHC fluid with the Citroen spheres? I’m about to pull the trigger on these and it didn’t even cross my mind whether the AHC fluid I have would be compatible.
 
The AHC system is a closed hydraulic system. So, I think the best alternative would be a hydraulic oil. But why not use AHC fluid?

Hydraulic oils are non-detergent. I suspect the AHC fluid is non-detergent as well. Motor oil and ATF have detergents. I would not use these in the AHC system because they will pick up contaminants and spread them through the system (because AHC does not have a filter).
 
does the AHC fluid evaporate?

All oils will experience some rate of evaporation. However, the loss will be very minimal in your AHC system because it is not open/exposed. In the interval of a regular fluid flush, you will not lose a meaningful amount of fluid.

To further enhance the discussion: because it is slightly cheaper, I recommend using raspberry jam (organic, with seeds) instead of Toyota's specifically designed fluids.
 
All oils will experience some rate of evaporation. However, the loss will be very minimal in your AHC system because it is not open/exposed. In the interval of a regular fluid flush, you will not lose a meaningful amount of fluid.

To further enhance the discussion: because it is slightly cheaper, I recommend using raspberry jam (organic, with seeds) instead of Toyota's specifically designed fluids.
I have a small leak around the front cross member/ wheel well area and the fluid evaporated on my driveway. I figured it was AHC
 
I have a small leak around the front cross member/ wheel well area and the fluid evaporated on my driveway. I figured it was AHC
Or was it condensation water from the AC?
 
Good day guys, I am new to the forum.
I just bought a 2000 lx470 with a bit over 88000miles. Yes, I understand that is nothing, but I live in Nassau in the Bahamas and this used to be a wealthy banker's car. There is a saying here that goes "if you didn't bring it with you, you are not going to find it here" so everything needs to be imported.
I say this because at the Toyota/Lexus/Mini/Suzuki/Hyundai/BMW dealer they have no idea what I am talking about when I mention the AHC, globes, sensors and worst of all the fluid.
I found it online but there is a 45 to 65% duty tax on all car parts applied after transport cost.
The car is in great shape but being a 21 year old car it means that the ahc might be in trouble.
I want to perform a flush to evaluate if the system is salvageable or if I should just go with a 2.5" OME replacement, but don't want to spend that amount of money for fluid that I might be just discarding if I discover that the system is beyond repair.
There is a lot of heavy equipment here so I suppose I can find the Dexron VI oil. Is this a good idea as a temporary alternative?
The problem I have seen with the AHC is that at Hi mode the back of the car is going in Pogo stick mode.
Any mods or test will be performed by myself. No techstream available.

Thank you.
 
I wouldn't risk anything else than the OE AHC fluid, or maybe the Citroen fluid if in an emergency.
If you give the dealer the part number for the fluid, would they be able to get it for you?
The pogo stick is probably a sensor problem - time to read the long and winding threads on the issue in here. Depending on your skills, it might be easier if you have TechStream.
For new sensors, if needed, you can use the cheap dorman versions. = much less tax. Is there a limit to max value before import tax kicks in, or is it from 1 $ up?
 
Good day guys, I am new to the forum.
I just bought a 2000 lx470 with a bit over 88000miles. Yes, I understand that is nothing, but I live in Nassau in the Bahamas and this used to be a wealthy banker's car. There is a saying here that goes "if you didn't bring it with you, you are not going to find it here" so everything needs to be imported.
I say this because at the Toyota/Lexus/Mini/Suzuki/Hyundai/BMW dealer they have no idea what I am talking about when I mention the AHC, globes, sensors and worst of all the fluid.
I found it online but there is a 45 to 65% duty tax on all car parts applied after transport cost.
The car is in great shape but being a 21 year old car it means that the ahc might be in trouble.
I want to perform a flush to evaluate if the system is salvageable or if I should just go with a 2.5" OME replacement, but don't want to spend that amount of money for fluid that I might be just discarding if I discover that the system is beyond repair.
There is a lot of heavy equipment here so I suppose I can find the Dexron VI oil. Is this a good idea as a temporary alternative?
The problem I have seen with the AHC is that at Hi mode the back of the car is going in Pogo stick mode.
Any mods or test will be performed by myself. No techstream available.

Thank you.
Hop on your speed boat, spend a fun weekend in Miami, buy what you need at the local Mr. T dealership, then return home. Stash the AHC fluid in drinking bottles, claim it is pink lemonade!

Kidding aside, AHC fluid isn't obscenely expensive. If you get yourself 6L, you'll have enough for two full flushes and only pay one set of shipping costs (in theory).
 
Does anyone know the composition of the Toyota AHC fluid? Is it mineral based/other?

Not saying a reasonable 'alternative' isn't available, but it seems to me that a 'substitute' (of like composition) would be the safer way to go.

I'll just stick with the Toyota product since it is readily available to me.
**Disclaimer: I ain't no chemist**

TLDR: I put in several hours research to find an equivalent fluid. I couldn't find any support that ATF or Brake Fluid were equivalent substitutes. I didn't check other car manufacturers' AHC fluids. I'm planning to stick with Toyota's fluid.

The MSDS suggests is is ether based with some light and medium paraffins. Brake fluid is also ether based, but is significantly more complex.

ATF is much gentler to almost all materials than ether based lubricants (and bonus: it doesn't absorb water), but I would be concerned that the viscosity is not the same. The AHC fluid not only holds up the vehicle, but also provides damping by pushing the fluid through a small opening (as all oil-based dampers do). Thicker fluid = stiffer dampening. I've ordered a jug of Toyota AHC fluid, I'll see if I can compare the viscosity by timing a fixed volume of each through a small funnel.

In my experience spec'ing lubricants for work, you avoid ether based fluids if you can, because it is acidic and because it absorbs water, which increases the maintenance requirements and increases the risk of corrosion to components. The big plus of it is it has the highest temperature limit. If you are driving the never-ending washboards of the Australian outback ATF might overheat. If you drive like me, this probably isn't an issue.

I've attached the AHC MSDS if someone else wants to take a crack at it.
 

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, I'll see if I can compare the viscosity by timing a fixed volume of each through a small funnel.

If you want to look up the viscosity of certain ATF's....then you can just compare it to the AHC specs:

AHC fluid: Viscosity @40C = 10.2 cSt; @100C = 2.83 cSt
 
**Disclaimer: I ain't no chemist**

TLDR: I put in several hours research to find an equivalent fluid. I couldn't find any support that ATF or Brake Fluid were equivalent substitutes. I didn't check other car manufacturers' AHC fluids. I'm planning to stick with Toyota's fluid.

The MSDS suggests is is ether based with some light and medium paraffins. Brake fluid is also ether based, but is significantly more complex.

AFT is much gentler to almost all materials than ether based lubricants (and bonus: it doesn't absorb water), but I would be concerned that the viscosity is not the same. The AHC fluid not only holds up the vehicle, but also provides damping by pushing the fluid through a small opening (as all oil-based dampers do). Thicker fluid = stiffer dampening. I've ordered a jug of Toyota AHC fluid, I'll see if I can compare the viscosity by timing a fixed volume of each through a small funnel.

In my experience spec'ing lubricants for work, you avoid ether based fluids if you can, because it is acidic and because it absorbs water, which increases the maintenance requirements and increases the risk of corrosion to components. The big plus of it is it has the highest temperature limit. If you are driving the never-ending washboards of the Australian outback ATF might overheat. If you drive like me, this probably isn't an issue.

I've attached the AHC MSDS if someone else wants to take a crack at it.
Thank you for the MSDS. The Toyota/Lexus AHC Fluid container (2.5 litre drum) only gives a vague idea of the ingredients. The stuff is 'made' for Toyota by Japanese oil company Idemitsu Kosan Co.

Toyota AHC Fluid label.jpg
 
Thank you for the MSDS. The Toyota/Lexus AHC Fluid container (2.5 litre drum) only gives a vague idea of the ingredients. The stuff is 'made' for Toyota by Japanese oil company Idemitsu Kosan Co.

View attachment 2598228
Yeah, I contacted Idemitsu for a part number since N A P A carry Idemitsu fuids. Idemitsu responded that the make the AHC fluid exclusively for Toyota.

Screenshot_20210227-222047_Outlook.jpg
 
Any update on the Citroen globes? Still working?
I have been using them for 2.5 years with toyota AHC fluid without any issue. When I ordered from pleiades, I discussed with them and their view is that lifespan of their product should match or exceed Toyota.
My Dad kept a Citroen DS for 25 years and never needed a sphere change. Citroen knows how to make durable spheres.
 
I have been using them for 2.5 years with toyota AHC fluid without any issue. When I ordered from pleiades, I discussed with them and their view is that lifespan of their product should match or exceed Toyota.
My Dad kept a Citroen DS for 25 years and never needed a sphere change. Citroen knows how to make durable spheres.
Here are a few more details on the ingredient 2,6-di-tert-butyl-p-cresol as mentioned on the container in the picture in Post #33 in this thread -- way beyond my paygrade on organic chemistry!!
Chasing down the "CAS No's" mentioned in the MSDS gives a few clues -- but what do we really know about what else is in the brew or what really makes it 'special' and exclusively fit-for-purposes?? Nevertheless, for peace of mind I will use only the Toyota-labelled AHC Fluid in my AHC system.
 
I would not use brake fluid in AHC system. It may damage all rubber seals and plastic.

If you must, test brake fluid with one of the AHC rubber O-rings (new OEM) first. One could simple place o-ring and brake fluid in sealed container, and let soak (the longer the better) for say a week. Then match up to a new o-ring. Any distortion, change in feel, color, flex, etc. do not use.

If it does not damage rubber or plastic and used in the AHC system. You'll likely need to flush very very often. As the moisture will likely build-up very very fast in the brake fluid.
 
If you want to look up the viscosity of certain ATF's....then you can just compare it to the AHC specs:

AHC fluid: Viscosity @40C = 10.2 cSt; @100C = 2.83 cSt
Dextron VI Viscosity @40C = 30.2 cSt; @100C = 5.9 cSt. Not close enough, in my opinion, when cold. Flash Point is 220 °C (428 °F) which is plenty high (for reference, DOT 4 brake fluid is 203 °C (397 °F)
Chasing down the "CAS No's" mentioned in the MSDS gives a few clues -- but what do we really know about what else is in the brew or what really makes it 'special' and exclusively fit-for-purposes??
Yes this is exactly what steers me toward staying OEM (and I'm not prone to that). I thought I was being clever several years ago by not buying a special-BMW-only gear oil (which was 3x cost). I found out the hard way that it really was specially formulated for the application. I was successful in getting an equivalent fluid in basic properties, but BMW had added some additives that were needed for correct function. I didn't break anything, but lesson learned: specialty fluids aren't (always) just to direct money to the manufacturer.
 
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My Mercedes has AHC as well, but it's called ABC, active body control. I use this fluid for the system

Pentosin.jpg



I wonder if it can be a substitute, they're sold at local autoparts or you can get them online for about $15 a liter.
 

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