alternative fluids for AHC system

Is Dexron VI a good substitute for AHC fluid?

  • Yes, works great for me

    Votes: 4 19.0%

  • No, causes major problems

    Votes: 11 52.4%

  • Probably

    Votes: 5 23.8%

  • There are better choices than either Dexron or Toyota AHC fluid

    Votes: 1 4.8%
  • Total voters
    21

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ylexot

ylexot

10 Year 15 Year
Joined
Jun 25, 2006
Threads
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653
Location
Ridgefield, WA
I was talking to Keith over at B&B Suspensions the other day and one of the topics was the AHC hydraulic fluid. He recommended using Dexron VI instead of the Toyota AHC fluid. It is cheaper, has better thermal performance, and according to him meets or exceeds other requirements for the system.

It was a good chat and Keith seems knowledgeable and helpful trying to sort out these systems. I wondered how many have followed this kind of advice and what the results were.
 
ylexot said:
I was talking to Keith over at B&B Suspensions the other day and one of the topics was the AHC hydraulic fluid. He recommended using Dexron VI instead of the Toyota AHC fluid. It is cheaper, has better thermal performance, and according to him meets or exceeds other requirements for the system.

It was a good chat and Keith seems knowledgeable and helpful trying to sort out these systems. I wondered how many have followed this kind of advice and what the results were.
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Based on past posts here and on at least 1 other Lexus forum, be aware that Keith pushes his own sourced AHC components.

It's difficult to believe that Dexron VI "meets or exceeds" other requirements for the system, as the two fluids could not be more different.

To me, AHC fluid is closer to standard tractor hydraulic fluid. Personally, I'll stick with Toyota AHC fluid and I'll continue to change it in the OCD mode of every 30K.

Steve
 
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I just came across this thread and after having AHC issues with a leaking line I to had a long chat with Keith. One of my take aways from that was to use DexronVI for a number of reasons that he seemed quite knowledgeable about.

I didn't buy anything from him, just got some knowledge on the whole system. I replaced a bunch of lines proactively and the system is filled with Dexron VI. So far all is well. I'll be the first to comment if there is an issue.
 
BOB F said:
I just came across this thread and after having AHC issues with a leaking line I to had a long chat with Keith. One of my take aways from that was to use DexronVI for a number of reasons that he seemed quite knowledgeable about.

I didn't buy anything from him, just got some knowledge on the whole system. I replaced a bunch of lines proactively and the system is filled with Dexron VI. So far all is well. I'll be the first to comment if there is an issue.
Click to expand...

For now Im good with price and performance of Toyota fluid.
I would like to know the number of reasons Keith shared with you for switching to DexronVI?
ILVAHC
 
It was a few months ago but a couple things I recall were 1) because of the price point of the Toyota branded product and as a result of some of the things he was seeing in his rebuild biz he feels that there is black marketing of the cans and fluid. He doesn’t trust the pipeline of the branded product at all.

He went into some interesting chemistry about dexron VI that I don’t remember but he did say he knew the product extremely well as he worked at Chevron (I think) when they were developing it and said it is the best suited product for the AHC applications.

Give him a call. He really gave me a ton of his time helping me get familiar with the system etc. and I didn’t need ot buy a thing from him.

After I fixed my issue and got things straightened out I called him
Back just to say thank you and he was as pleasant as can be and appreciative. I wouldn’t hesitate to ring him again if the need arises.

DexronVI is in any auto parts place. It’s only made by one manufacturer so don’t worry about the brand. Just get DexronVI.
 
2 cents:
Here, Dexron VI costs 4 times as much as AHC fluid. (Didn't check cost for a whole barrel)

When my first ahc-cruiser was new to me, and to the dealer, they advised me that I could use brake fluid instead of ahc fluid. So I did, when I was days away from the nearest ahc fluid and the fluid a bit low. It was OK for nearly a year, but by then the brake fluid had eaten through the diaphragms in the spheres (accumulators), first the fronts. Looks like all the other components handled it well though. It was OK for many years, after a thorough rinse of the system (shocks off) and replacement spheres. Not saying that the Dexron VI is anything like brake fluid. Brake fluid does seem to be quite harsh, as does ahc fluid.
 
Not sure where you are but a simple search on Amazon yields AHC at $.58 an ounce and dexron vi at $.46 ounce

Brake fluid and dexron VI are very different products. Brake fluid will remove paint and dissolve rubber over time. I do not believe Dexron VI acts like that.

When I installed my hydraulic car lift in my garage it called for Dexron VI in the pump reservoir.
 
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.
 
Just a different point of view on using alternative fluids, and I am NOT saying to use this in your AHC system, but when I drove cement truck we used Shell Rotella 15w-40 in literally everything, it was rated for hydraulic use and Allison transmissions. So thats what we used in the hydraulic system on the trucks, dozers, front end loaders...automatic transmissions...everything...with zero problems.

So Keith might be right and he's just going against the grain, and we all know where that gets you.
 
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Spike555 said:
So Keith might be right and he's just going against the grain, and we all know where that gets you.
Click to expand...
Might be very right. Aginst the grain is always hard, unless you are into all kinds of alternative movement. Just not worth it for me. Wish I knew an industry-engine-chemist.
 
Whereas trans fluid may work in AHC, I never like mixing fluids. It would be extremely difficult to get all the old completely out of AHC system. If I was going to switch, I'd go with M1 syn ATF which cost about the same. So someone would have to demonstrate a benefit for me to consider.

Seem the Toyota fluid works fine, with one exception I've noticed. Which is contaminants (small particles) in system not regular flushed.
 
Citreon cars, who are the inventors of this system and allow companies like Rolls Royce to use it under license has a list of alternatives.

1. Best to use LHM which is citreons version of AHC fluid.

2. 2nd best is aviation hydraulic fluid.

3. 3rd best is dexron ATF fluids.

30w engine oil can be used in a emergency.

Brake fluid was used in the USA as LHM wasn't available, this was done from the factory and was what the handbook specified. The problem with brake fluid is that it absorbs water and causes rusting of the internals so frequent fluid changes where needed.

The best fluid for a system is the one that has been designed for the materials used in the seals. Citreon has changed there fluid to suite different seal materials. So the best oil is the correct oil, as even citreon fluid could react with the seals in a toyota system.
 
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.
 
Julian Stead said:
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.
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Pics?
(...or it didn't happen...)
 
IMG_1284.webp
Here is a pic, it is covered in dinitrol for the winter but you can make it out.
 
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