1955 Buick Dynaflow Leaking from top.

[snowman1510]

Good evening, thanks to the help of John here on the forums, I've got a new throttle control linkage! I have new wheel cylinders and my wife helped my bleed the brakes. They are now nice and stiff instead of going straight to the floor. I was going to try to take it on a test drive this evening. When I got the vehicle it leaked trans fluid all over my garage. I refilled it tonight after the engine warmed up. I let the vehicle warm up while it was set to park and began to check the trans dip stick while it was warm.

 

Not a drop on the dipstick. I slowly added a whole gallon while stopping at regular intervals to check the fluid level. A drop never showed on the dip stick. I then looked under the vehicle and saw a large leak coming from somewhere on top of the transmission (the puddle on the floor did not indicate all the fluid I put in had leaked out). Did I hit some type of overfill?

 

I also heard there might be a vent at the top with some issue. I also understand there are breather tubes, but I saw nothing coming out of the tubes that are located next to the trans.

 

I did have the engine running when I put new fluid in. Was this incorrect? When I shut off the vehicle the leak ceased and only the drips remained. When I turned back on, it did begin again. 

 

Any help in pointing me in the right direction would be helpful. Thanks for your time!!!

 

MODS: I accidentally posted this same question in a general discussion forum. You can dispose of that listing if you'd like.

[195354]

I would look into your cooler lines to the heat exchanger possibly leaking. Not sure of the routings on a 55. On my 53 they are on the RH side toward the back about 3 o’clock. If they are similar it could spray on the top. Check the service manual for quantities of fluid needed sounds like it’s leaking out as fast as you can put it in.

If l remember correctly on my 53 l added 6 quarts engine not running. I had fluid on stick it was over full. Started engine and adjusted levels as it filled torque converter. If the service manual states fluid amount in pan drain fluid. Then add appropriate amount and check dipstick should be full.  This will help you confirm you have the correct dipstick.

 Some of the forum threads might have some views showing the lines on a 55 

Steve

 

 

 

[old-tank]

I had one that blew fluid out of the vent at the top of the transmission but only at highway speeds.

You need to find out where it is leaking and when it is leaking engine running or not.

The upper part of the transmission filler tube needs to be against the lower portion of the transmission filler tube and then coupled together.

As a test drain the transmission pan and measure what you drained out; there should only be about 4 quarts in the transmission pan.  Do this after it had been running and shifting into years okay since  with disuse the torque converter can drain into the pan over filling it.

Edited November 6, 2023 by old-tank (see edit history)

[snowman1510]

Thank you! I'll try this tonight! So it should be fine if I briefly shift through the gears?

[snowman1510]

I had it run in park saw it begin to spew the trans fluid again. I switched to neutral. It stopped. I put it in park again and it didn't spray anymore. Fluid has begun to show on the dipstick now. Bonus is my parking brake light decided to come back to life!