Tranny leak fix

Well I've had a small front tranny seal leak for about a year.A few days ago I bought a product caled "No Leak" at the local Canadian Tire store.It's designed for manual and automatic transmissions.I don't know how long this "Fix" is going to last,but the damn leak is gone!!I must say I have concerns that maybe something may happen inside later,but it shifts smoothly and no leak.Just thought I'd pass this on. It's red in colour and in a clear plastic bottle FYI and about the same weight as ATF fluid. About 55mikes on the car since it was put in.
I hope it works.I screwed up & forgot to change the front seal when I had the engine & tranny out of the car while I was restoring it 1 1/2 years ago.

John, the stuff "attacks" and softens the neoprene seals and swells them just a little. Probably no harm in leaving it in with the lube but on the other hand it doesn't take much effort to drain and refill it either. I could be concerned about continuing to over soften and actually ruining the material so if I were doing it I would drive the car for another couple of hundred miles and then change back over to straight lubricant.

Jack

I just used some Lucas Transmission additive in my 3000 Ford Tractor that had a front seal leak. Stopped the leak in its tracks.

At a GM dealership we routinely added a similar product to automatic transmissions that were experiencing slight leaks. GM put the product out under their part number. In many cases the swelling of the seals was an effective cure for slight leaks. I don't recall any untoward side effects.

I've probably just forgotten, but I only recall paper gaskets on the transmission, not rubber or neoprene with the exception of the seal the runs on the main shaft. All my leaks appear to be from the paper gaskets.

I've heard that adding a small amount of alcohol based brake fluid (DOT 3 or 4) to the sump (engine, gearbox, etc.) accomplishes the same thing? The alcohol causes the viny-butyl based seals to swell.

John Morrison

Here's a further update on my so-caled fix. It actually started leaking worse than before!
I probably put 200 miles on it since I put in the "No Leak" ... I've now drained the Tranny & put in the proper Castrol oil