Bracket Talk
Powerglide fluid level and gasket

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September 17, 2019, 08:33 PM
Bucky
Powerglide fluid level and gasket
Ok this is mundane. But twice in the last 5 years I have had a pan gasket start pushing out and leaking. Mostly at rest in the shop. I have a deep pan, and what I think is a stock depth screw in dipstick. The filter has a 1" spacer. My cooler is above the transmission, and I have a catch can on the front of the pan.

Should the fluid level touch the gasket when at rest not running? With a deep pan and a spacer, what is the logical way to set the level?

Oh, and what gasket is your favorite type?


Foxtrot Juliet Bravo
September 18, 2019, 05:09 AM
Alaskaracer
I use the FARPAC gaskets. Never failed me. As to level, I pour in 4-5 quarts and see what the level is, then start it and add to it until it's full.


Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com
"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
September 18, 2019, 05:16 AM
TD3550
FARPAC.
September 18, 2019, 08:53 AM
Mike Rietow
OP have you tried cork? LoL!

You need a fiber gasket OP as said like a farpak, or Felpro makes a standard thickness rubber with metal inserted gasket for a cast pan.

For a fabricated aluminum pan like a Sonnax or Moroso it'll be either a Coan rubber gasket w/metal insert or a moroso rubber w/metal. These may call for a stud kit because they're probably 1/4" thick, this option (stud kit) dependent on how long a pan bolt you currently run.

The only way to properly check oil level is with engine running with the transmission gear selector in park and the torque converter bolted to the flex plate. Although before this will measure the oil level exact, you'll need to verify the full mark on the dipstick itself, is properly marked/oriented. Very seldom are they.

This message has been edited. Last edited by: Mike Rietow,
September 18, 2019, 08:56 AM
Woody B
When you car is parked the fluid from the convertor drains back into the trans. This raises the level. It's common to see pan gasket leaks on many types of transmissions when parked for a while. The running fluid level is just below the pan gasket level.


I used to be a people person, but people ruined that.
September 18, 2019, 09:16 AM
Mike Rietow
quote:
Originally posted by Woody B:
When you car is parked the fluid from the convertor drains back into the trans. This raises the level. It's common to see pan gasket leaks on many types of transmissions when parked for a while. The running fluid level is just below the pan gasket level.


No sir. It's .750 above the edge of the pan rail.
September 18, 2019, 09:26 AM
chasracer
I believe according to Munroe's book, the stick should be marked as full right at the bottom of the pan mounting rail. That's where I have mine at and it seems to work okay. I have pretty much the same setup as you do - deep pan, lowered pickup, cooler above the trans and a catch tank.


Save on Fuel - GetUpside - https://upside.app.link/jE7eqmHc2z
September 18, 2019, 10:24 AM
Mike Rietow
OP, measure at the angle the stick comes through the case.

https://images.squarespace-cdn...rans.jpg?format=750w
September 18, 2019, 10:45 AM
Rawe Power
I've never had problems with the pan gasket leaking... but I have repeated problems with fluid leaking at the transbrake solonoid. It leaks past the threads, not through the solonoid. It's a very slow leak that shows up after the car sits for a few days.

I've replaced solonoids and even cases (stock PG cases) and the struggle continues. I've tried different combinations of gaskets, o-rings, RTV and purple Loctite gasket maker, with no change. My fluid level is just high enough (without the engine running) to dribble out when I remove the solonoid.

Has anyone else ever had trouble with fluid leaks at the solonoid? Is there a viable solution other than simply running less fluid?


Ben Rawe 383H
1965 Chevy II Nova
September 18, 2019, 11:29 AM
Bucky
Good info thank you.


Foxtrot Juliet Bravo
September 18, 2019, 12:32 PM
Mike Rietow
quote:
Originally posted by Rawe Power:
I've never had problems with the pan gasket leaking... but I have repeated problems with fluid leaking at the transbrake solonoid. It leaks past the threads, not through the solonoid. It's a very slow leak that shows up after the car sits for a few days.

I've replaced solonoids and even cases (stock PG cases) and the struggle continues. I've tried different combinations of gaskets, o-rings, RTV and purple Loctite gasket maker, with no change. My fluid level is just high enough (without the engine running) to dribble out when I remove the solonoid.

Has anyone else ever had trouble with fluid leaks at the solonoid? Is there a viable solution other than simply running less fluid?


As mentioned that's the converter oil draining filling the sump higher than the solenoid. I thinks that's common with a stock case (leaking through threads). An aftermarket won't do that. I think if it were me I'd use some teflon pipe dope and let it setup a week in between race's. Might get lucky. A nice reasonably priced aftermarket case is a Transmission Specialties if you can locate one. Always sold out it seems.

It's definitely not a viable solution under filling it with oil, unless it not leaking is the higher value than a sizzled powerglide (sarcasm).
September 18, 2019, 12:43 PM
Rawe Power
quote:
Originally posted by Mike Rietow:
quote:
Originally posted by Rawe Power:
I've never had problems with the pan gasket leaking... but I have repeated problems with fluid leaking at the transbrake solonoid. It leaks past the threads, not through the solonoid. It's a very slow leak that shows up after the car sits for a few days.

I've replaced solonoids and even cases (stock PG cases) and the struggle continues. I've tried different combinations of gaskets, o-rings, RTV and purple Loctite gasket maker, with no change. My fluid level is just high enough (without the engine running) to dribble out when I remove the solonoid.

Has anyone else ever had trouble with fluid leaks at the solonoid? Is there a viable solution other than simply running less fluid?


As mentioned that's the converter oil draining filling the sump higher than the solenoid. I thinks that's common with a stock case (leaking through threads). An aftermarket won't do that. I think if it were me I'd use some teflon pipe dope and let it setup a week in between race's. Might get lucky. A nice reasonably priced aftermarket case is a Transmission Specialties if you can locate one. Always sold out it seems.

It's definitely not a viable solution under filling it with oil, unless it not leaking is the higher value than a sizzled powerglide (sarcasm).


What's different in an aftermarket case that prevent leaking through those threads?

Draining 1/2 a quart of fluid would probably be enough to stop the leak. That wouldn't be enough to fry a PG with a deep pan and good cooler. But, if that option didn't bother me, I would have done it already.


Ben Rawe 383H
1965 Chevy II Nova
September 18, 2019, 02:28 PM
MOPDRAGSTER
I have had a solenoid leak at threads before. I switched to a thin oil drain plug gasket instead of the dinky paper gasket.. I personally like the fiber ones you have to "thread" onto the solenoid because the hole is a little small. I think they are 1/2 or 12mm.
the added thickness hasn't affected operation of TB but I would check it.
September 18, 2019, 05:13 PM
Bucky
quote:
Originally posted by TD3550:
FARPAC.


That’s what is going on


Foxtrot Juliet Bravo
September 19, 2019, 08:24 AM
Cashflow
On the solenoid leak I build my own gasket out of thin gasket material and I make the opening small enough that I also have to "thread" it on.

I use a small amount of "Right Stuff" silicone on it and also make sure the internal threads are clean and put a dab of Right Stuff on the threads of the solenoid.

No leaks!


Clowns to the left of me, Jokers to the right. Here I am.......
September 19, 2019, 10:06 AM
Mike Rietow
quote:
Originally posted by Rawe Power:
quote:
Originally posted by Mike Rietow:
quote:
Originally posted by Rawe Power:
I've never had problems with the pan gasket leaking... but I have repeated problems with fluid leaking at the transbrake solonoid. It leaks past the threads, not through the solonoid. It's a very slow leak that shows up after the car sits for a few days.

I've replaced solonoids and even cases (stock PG cases) and the struggle continues. I've tried different combinations of gaskets, o-rings, RTV and purple Loctite gasket maker, with no change. My fluid level is just high enough (without the engine running) to dribble out when I remove the solonoid.

Has anyone else ever had trouble with fluid leaks at the solonoid? Is there a viable solution other than simply running less fluid?


As mentioned that's the converter oil draining filling the sump higher than the solenoid. I thinks that's common with a stock case (leaking through threads). An aftermarket won't do that. I think if it were me I'd use some teflon pipe dope and let it setup a week in between race's. Might get lucky. A nice reasonably priced aftermarket case is a Transmission Specialties if you can locate one. Always sold out it seems.

It's definitely not a viable solution under filling it with oil, unless it not leaking is the higher value than a sizzled powerglide (sarcasm).


What's different in an aftermarket case that prevent leaking through those threads?

Draining 1/2 a quart of fluid would probably be enough to stop the leak. That wouldn't be enough to fry a PG with a deep pan and good cooler. But, if that option didn't bother me, I would have done it already.


I assume the difference is when you turn a solenoid into an aftermarket case, there is resistance. My claim you won't see a leak in that area with an aftermarket case isn't exactly correct, I'll clarify. I haven't seen or heard of any aftermarket case's I've used, leak in that area, no extra prep.

Deep pan,ten coolers or not there's a risk running the oil level low. The percentages of risk go up dependent on where the full mark on the dipstick is oriented to the bottom of the pan. As example, if you had a 9.75" deep pan with a 4" filter extension/pickup adapter and the full mark on the stick is 9.25" off the bottom of the pan, you're in the same boat as if you have a 2.75" deep pan with a 1" filter extension/pickup adapter and the full mark on the stick is marked 2.25" off the bottom of the pan. You're around 2 quarts of oil low give or take a little with the engine running in park with the converter attached to the flexplate. If you were to drain a half quart in this scenerio, the percentages the transmission would sizzle are real high. Viable is relative. The full mark on the stick measures the oil level dependent on it's orientation to the bottom of the pan, with the highest value being the oil level, not the capacity of oil in the system (sump area).
September 19, 2019, 10:49 AM
Woody B
quote:
Originally posted by Mike Rietow:
quote:
Originally posted by Woody B:
When you car is parked the fluid from the convertor drains back into the trans. This raises the level. It's common to see pan gasket leaks on many types of transmissions when parked for a while. The running fluid level is just below the pan gasket level.


No sir. It's .750 above the edge of the pan rail.


Listen to Mike. It's been a couple decades since I've been in a powerglide.


I used to be a people person, but people ruined that.
September 19, 2019, 11:31 AM
Mike Rietow
quote:
Originally posted by Woody B:
quote:
Originally posted by Mike Rietow:
quote:
Originally posted by Woody B:
When you car is parked the fluid from the convertor drains back into the trans. This raises the level. It's common to see pan gasket leaks on many types of transmissions when parked for a while. The running fluid level is just below the pan gasket level.


No sir. It's .750 above the edge of the pan rail.


Listen to Mike. It's been a couple decades since I've been in a powerglide.


No sir, this is GM.

https://images.squarespace-cdn...rans.jpg?format=750w
September 23, 2019, 08:04 AM
Bucky
I installed that gasket last week. Filled, ran, set fluid height just above rail. No leaks. Sat for 4 days, no leaks. Go out yesterday and there is a puddle under the car. Wet along the rear pan gasket. Nothing under the seal. Ran my finger under the solenoid and that seemed to be dry. So I'm guessing it is coming out where it is showing....the gasket. I put it on dry. Pan and trans surfaces were pretty darned clean and good condition. I thought I had this licked.


Foxtrot Juliet Bravo