Brake Fluid in transmission

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Last week, I was telling my brother about my transmission in my '93 Ford Taurus, (so far, transmission is working). He told me, "The next time it starts acting up, pour in a bottle of brake fluid, cleans 'em right up and makes 'em last longer." More discussion followed and he swears he has done this. One example he gave was an old Chevy truck with a dying transmission at 150,000. He poured in the bottle of brake fluid and tranny made it to 178,000 miles.

So okay, I put this little info in my mental "fix it" box for possible use later. Then I see an experiment here on Bitog where ATF is mixed with DOT 3 brake fluid clearly showing that they do not mix.

Now I'm wondering, did my brother's transmission survive IN SPITE of his addtion of brake fluid to the transmission, or is there something behind what he is saying about "cleaning and restoring bands and valve bodies"?

Opinions?
 
These old-wives' tales about putting some other type of automotive fluid in never cease to amaze me.
 
I wouldn't do it for a free replacement transmission if mine died... but there's actually likely a bit of truth in this old wives' tale. The glycols in DOT-3 brake fluid will soften and swell some rubber and plastic materials to an amazing degree. A small dose might soften up dried/crispy piston seals just enough to let them work better- for a while. When the original A-727 in my '66 Polara was in its final days, circa 1998-2000, it got to the point that the direct clutch would just refuse to engage when cold. I'd have to drop it in reverse and warm the fluid with the torque convertor for a few minutes on sub-freezing days. I discovered that a shot of Trans-X would make it work for a couple of weeks at a time, and IIRC the old Trans-X was an alcohol/glycol brew. Got through maybe 2 winters that way, and when I finally did overhaul the transmission the direct clutch seal was the texture of spaghetti noodles as they come out of the bag. It shattered into crunchy bits coming off the clutch piston.
 
Some people can't help just 'doin things'. Its not about the thinking.

Like, ATF can be used to clean out your engines!

Why? Auto trannies are really clean in side cause ATF has lots of detergents.

Really? No. ATF has a fraction of the detergents of engine oil. Auto trannies are 'really clean' because they are (almost) a sealed hydraulic environment with no combustion by-products.

But still, put some of that ATF in yer engine and it'll clean it right up! I throw a bottle in just before an oil change and it works every time!

(no ... no I don't)
 
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Originally Posted By: zzyzzx
I've done this a few times and it helped every single time. It sometimes takes while before the effect fully works though.


What were your tranny symptons and what did the brake fluid add fix and how long did it last?

If this is a seal sweller, I'm thinking my leaky 700R4 ('86 Chevy Astro Van) might just be a candidate for this add.
 
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