1957 Transmission leak when parked

[sterheggen]

Hi everyone. T-Bird newbie here. I bought a 1957 bird from an online auction and when I got it home it just sits in the garage. When sitting for long periods it drips a ton of tranny fluid. I finally got a shop built and put it on a lift and can’t really see an obvious leak. Right after purchase, I took it to a mechanic for a vacuum leak and a few other things and he said that there is an “overflow” on the granny and when not run much it will leak. I filled the tranny fluid, started the car and put it on the lift and it hasn’t leaked in 2 days. It’s very frustrating that when it sits it leaks A LOT but not all the time. Any ideas on what could be going on?

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[ICON 56]

You would need to replace the end seal of the tranny See this video from You Tube.

 

[Tom Alpers]

When it sits for a while the fluid in the torque converter can drain back into the main body of the tansmission. When that happens the non-running fluid level will be higher than normal "full" level and can be higher then some of the side seals. Side seals that don't leak enough to notice under "normal full" may leak out fluid when it's "too full" from the drain back.

 

[vernz]

Agree with Tom Alpers. I have the same issue and was told to keep the transmission oil level at the low end of the acceptable range. I used to top it up to the high end. I still have some leakage but it is reduced.

 

[Bruce Hardy]

Hi everyone. T-Bird newbie here. I bought a 1957 bird from an online auction and when I got it home it just sits in the garage. When sitting for long periods it drips a ton of tranny fluid. I finally got a shop built and put it on a lift and can’t really see an obvious leak. Right after purchase, I took it to a mechanic for a vacuum leak and a few other things and he said that there is an “overflow” on the granny and when not run much it will leak. I filled the tranny fluid, started the car and put it on the lift and it hasn’t leaked in 2 days. It’s very frustrating that when it sits it leaks A LOT but not all the time. Any ideas on what could be going on?

What needs to be done is you'll need to have that converter seal(valve) replaced which will cure your problem. Otherwise put a pan under the trans to catch the oil from the overflow vent.