Technical Oops, Dot 3 in a TH400 ?

A Bud has been wankin' on a 31 Ford for a decade + & got it running recently.
Guess the SBC sounds Bitchin'.
The trans is balky and does not want to shift.
It was a reman many years ago & not run.
Seems that when they were filling it up, a helper grabbed a can of ATF that looked funny as it went down the filler and this is where some old brake fluid had been contained.
"Not sure" how much brake fluid but the car has a good hour+ of running time.
He reports that the pan looked pretty gummy with some friction material in it plus a little "shiny stuff".
As far as I can find online, he is inter-coursed.
Anybody been there? (You Know, as far as the brake fluid issue... )

 

Yep if he is seeing crap in the pan, I'd say its toast.

Btw many years ago I heard of guys putting brake fluid down them to get a few more miles out of them. The brake fluid would swell up the seals and clutches and let them go a few miles more.

 

The brake fluid would swell the seals and o rings basically anything made of rubber.


I’m not proud of it ( ok maybe a little lol) but I would put 1-2 ounces of brake fluid in pwr steering systems of my winter beaters to stop minor rack or pump leaks, wouldn’t do it on a car that I wanted to keep or cared about, but a car that’s life expectancy was 3-6 months it worked for me.

he’s got nothing to loose by doing a flush and fill, but my guess is the trans won’t have a very long life expectancy.
No clue what brake fluid would do to the friction material but it probably would not be good.


Also, a years old rebuild it could have nothing at all to do with the brake fluid and just a shitty rebuild from years ago.


Fluids cheap, service it and go from there.

 

Rebuild it. It ain't all that hard. There are Youtube videos on how.

Contrary to what some believe, these are not space rockets. They are actually pretty straightforward.

The biggest obstacle to rebuilding one is a clean bench, that is big enough.

I did a TH350 for a friend, while he waited. I have a bench-mount holder, which adds speed. It took less that an hour.

 

change the filter, let it drain with pan off overnight and refill with proper fluid. might surprise you...

 

Change filter/etc, won't get ya anywhere. Fluid is in places you cannot see. how much in the TC?

Pull the tranny, pull the converter...get busy from there.

Filters and fluid are cheap...nice, not when you have to do it over and over. Mercy.

 

OH BOY!!! This is what I was told/learned many years ago: The "adhesive" used to "glue" the lining to the plates is actually WATER SOLUBLE. It can handle petroleum based fluids, but not water based, or those that absorb water (such as alcohol, that is hygroscopic). Based on that, I think the trans is shot, or will be very shortly, and attempting to run it will only make for things getting worse. Just remove the transmission now, and do a proper rebuild. I have heard of guys using a "little" brake fluid in various "assemblies" (not that I ever would), but never in an automatic transmission (or like I tend to call them, transamatic automissions). Hey!!!!, this ain't Pace Picante Sauce (there's actually a "joke" there from an article I read in a medical journal). I am Butch/56sedandelivery.

 

'56, Yeh. We know what dot 3 can do to paint & I just wonder what that friction material consists of!

 

I'd do a flush and refill, a couple of times, and see what you get. Depending on how much contamination there was, they might get lucky. Dump the oil in it now without running it any more. But with the next couple of flushes I'd get it good and hot to fully mix it up. There will be fluid in the converter and in the cooler, so draining the pan won't get it all out, there will be some retention. A couple of changes might get it all out, and fresh additives in the ATF might recondition the seals. IMO it's worth the try.

 

My buddies old C-6 took for ever to engage forward cold. He didn’t want t spend money on it. Put a 1/2 can of brake fluid in it and it worked perfect for at least 5 years. Brake fluid swells the seals up and make them pliable again.


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San Jose, 1962. Couple of (fast) racers told my pal Terry to pour some DOT 3 into his 371 Olds/dual range hydro that was in his '49 Ford coupe.
Terry followed the advice, I winced as he gave it the pour...but that hydro woke up and would spin the 8.20 tires when it upshifted to 2nd, then chirp 'em in 3rd! Tight on the upshifts...My, my. (my thought: 'How long can it last?')
Terry was in the Fremont high 12s, C gas, and the car was consistent all season.
He traded it off, all year with no tranny problems: Tradee replaced Olds w/SBC, so we never heard about the 'half life' being met.

However, as Butch and Vanderblas said: Beware after a short time.
Remove it and go thru it. Best idea...
BTW, we were 20 year old kids, and I was the only one that was a Journeyman mechanic. I still didn't like it...

 

I put a quart of 30w oil in my Taurus trans 6 years ago and it is still working fine. Not the first time I've done it.

 

You know I've heard the brake fluid trick many times over the years, but it made no sense to me. The seals in the brake system are rubber and they don't swell unless you put them in oil. I think I'm going to put some extra seals from a trans kit in some brake fluid and see what happens. I'm betting on nothing.

 

sounds like brake fluid might have been synthetic, gummy is exactly what it does when mixed with non synthetic petroleum product's. never seen it mixed with tranny fluid but have seen it mixed in a brake system can not be flushed. turns to jello

 

FINALLY!! A Voice of Reason! I was wondering when that claim would be questioned........

Ray

 

I've wondered too..they make stop leak that swell seals for engines, trans, steering.. not for brakes. Maybe because you don't put a band-aide on brake trouble, or maybe brake rubber shouldn't swell and cause issues.

 

I think it is near if not the front of the class of urban myths amazing what people will believe than swear it works when it does not to save face.then there is the one about oh never mind

 

Did you ever see what oil does in a brake system? Had a customer when I worked for a Dodge dealer who wanted a new seal for her master cylinder. Her teen age son had checked all the fluids and told her the master cylinder cover seal was bad. I popped the cap and found a seal about two or three times bigger than it should be. I told her that her son must have mistakenly put oil in the brake system and we needed it address the problem immediately. She got very indignant and told me her son wouldn't do that and left in a huff. This was on Saturday, on Monday I got a call saying her car was in traffic and it wouldn't move, and smoke was coming from the front wheels. Towed in, and we did a complete brake system. She paid the bill and never said another word about the incident.

 

Funny, how come it costs thousands to have them rebuilt?

 

I'm interested in hearing the result of your test. I hope you do follow through with it and post back here with the results.

 

With all due respect.If you are spending thousands to have a TH 350 rebuilt you are being ripped off.

 

The older rubber seals will swell for sure. Took one apart after brake fluid was run in it and the seals fell off the pistons when removed from the drums.


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Hi Bob,

Long time since I have seen you post....maybe not following the same threads.

In any case, I have thought of you from time to time andy wondered how you are doing?

Regards,
Ray

 

Different kind of rubber. I am not a rubberolgist, so I can't tell you what's different.
Back in the day putting brake fluid in a transmission, was the kind of stuff used car lots would put in transmissions that would not go into gear cold.
Real common in Ford transmissions back then. The seals in the clutch drums would get hard and not seal, until the trans warmed up.
Problem with doing that was, it would continue to attack the rubber until it fell apart. Then the trans would quit working. I have seen many of those over the years. Transmedic will do the same thing.
Kinda the same kind of fix as putting liver or sawdust in a rear end to cure gear noise.

Bill

 

All those automotive engineers can't be wrong to actually design something that works one way, only to have "someone else" come up with a "better" way of doing things. Here's your sign! I am Butch/56sedandelivery

 

Rent, utilities, equipment, equipment maintenance, materials, consumables, supplies, insurance, license fees, waste disposal fees, taxes, wages, worker's comp insurance, permits...should I go on?

I chose to absorb 100% of that, so a friend of mine who is down on his luck, can get his butt to work, reliably.

 

This man speaks the truth, and you should listen to him.

 

Hello Ray, Doing just fine here. Hope you are doing ok also. I don't post too much. Do you still have my e-mail address?

 

I dont disagree that there are many costs involved as I have a close family member in the automotive repair business. but unless the shop is removing and reinstalling the transmission , the rebuild of a TH400 should not cost thousands. Especially when you can buy fresh rebuilt ones from a host of reputable dealers for $1500 or less.

 

I ruined quite a few nice cars in my youth before I realized that those engineers actually know what they are doing. Now I tell all the younger guys the errors of my ways. As a professional truck technician, I sometimes wonder why you guys do things a certain way, but no longer try to change things.


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