1967 Powerglide Leaks-Does Not Make Sense

[Paul L.]

I store my 1967 327/300 with Powerglide in a commercial storage area each winter. The garage is heated and secure. Last winter I had occasion to change out the seats (restore, February) and there was a transmission fluid leak; about two US quarts. We moved the car and no more probems. In fact I drove the car during the summer of 2004 with no difficulty. No leaks at all.

I just had an estimator drop by that facility for a paint estimate and the darn Powerglide leaked another two quarts. How can a transmission leak when a a car is stored and not run? Doesn't make sense. Help!!

[Kevin M.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

They all do the seals dry up and leak, then you drive it and they warm up and don't leak. The only way a PG won't laek is driving it, that's how I take care of mine.

KEvin

[Kevin M.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

They all do the seals dry up and leak, then you drive it and they warm up and don't leak. The only way a PG won't laek is driving it, that's how I take care of mine.

KEvin

[Ralph Harlan]

Re: 1967 Powerglide Leaks-Does Not Make Sense

I had athe same problem with a '76 full size 4WD blazer (350 TH) and discovered that when it was run regularly that the fluid stayed up in the unit, but when it sat for over a month the fluid slowly settled into the pan. Since that much fluid in the bottom of the trans brought the level well over the design fluid level it ran out between the dip-stick tube and the case. Sounds like you've got the same situation.

[Ralph Harlan]

Re: 1967 Powerglide Leaks-Does Not Make Sense

I had athe same problem with a '76 full size 4WD blazer (350 TH) and discovered that when it was run regularly that the fluid stayed up in the unit, but when it sat for over a month the fluid slowly settled into the pan. Since that much fluid in the bottom of the trans brought the level well over the design fluid level it ran out between the dip-stick tube and the case. Sounds like you've got the same situation.

[Mike Cobine]

Re: 1967 Powerglide Leaks-Does Not Make Sense

Thanks for the tip, I bet my T400 in my pickup is doing the same thing. A couple of weeks ago, it just started leaking. Drops about a quart each time. It sat for a week while at the inlaws for Christmas, but then, it often sits about a week due to my long distance commute from my bedroom to work. Must be nearly 35 feet.

I haven't been under it to look yet, but I have been driving it and it is randomly dropping fluid. The day after driving down to Old Town, it dumped a pint or so on the driveway.

[Mike Cobine]

Re: 1967 Powerglide Leaks-Does Not Make Sense

Thanks for the tip, I bet my T400 in my pickup is doing the same thing. A couple of weeks ago, it just started leaking. Drops about a quart each time. It sat for a week while at the inlaws for Christmas, but then, it often sits about a week due to my long distance commute from my bedroom to work. Must be nearly 35 feet.

I haven't been under it to look yet, but I have been driving it and it is randomly dropping fluid. The day after driving down to Old Town, it dumped a pint or so on the driveway.

[Roy B.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

One -if the engine rear main crank bearing gets worn it allows the trans Converter that holds most of the oil to lower on the seal allowing oil to leak.
Two- The pressure piston spring gets weak and is unable to hold the valve seated tight letting the oil in the convertor to drain in to the main case.
Three- trans vent is clogged causing pressure build up.
Burping- is a loose or bad seal of the oil filter sucking air

[Roy B.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

One -if the engine rear main crank bearing gets worn it allows the trans Converter that holds most of the oil to lower on the seal allowing oil to leak.
Two- The pressure piston spring gets weak and is unable to hold the valve seated tight letting the oil in the convertor to drain in to the main case.
Three- trans vent is clogged causing pressure build up.
Burping- is a loose or bad seal of the oil filter sucking air

[Michael H.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

I agree with Ralph. If I remember correctly, (been 30 years) there are two anti drain back valves in the control body of a power glide. It's not uncommon for these to leak and cause converter drain back. They can be serviced without removing the transmission and it's really not a difficult task.

To test for this condition, check the fluid level, with the engine NOT running, soon after you shut it off. Check again before starting the engine in a few weeks to see if the level is above your mark from the first check.

Michael

[Michael H.]

Re: 1967 Powerglide Leaks-Does Not Make Sense

I agree with Ralph. If I remember correctly, (been 30 years) there are two anti drain back valves in the control body of a power glide. It's not uncommon for these to leak and cause converter drain back. They can be serviced without removing the transmission and it's really not a difficult task.

To test for this condition, check the fluid level, with the engine NOT running, soon after you shut it off. Check again before starting the engine in a few weeks to see if the level is above your mark from the first check.

Michael