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Valvoline Max Life 100% Synthetic #773775 was used
Here is what I tried so far:
OEM pan, Chrome Summit pan, Aluminum Summit pan
with the following gaskets GM 8654799 gasket, MAHLE cork gasket 1216M, random paper gasket (came with filter), Fel Pro 18663 gasket, Moroso reusable gasket
and with the following sealants: dry (no sealant), Permatex 80062 Hi Tack, Permatex Aviation/.300, Gasgacinch 440-A, Permatex Automatic Transmission Gasket Maker 81180
It leaks either along the rail or past the bolts, or both
Always cleaned both surfaces with lacquer thinner before install;
Always torqued to 108" lbs on first install, then re-torqued again and again as needed- fasteners all kept loosening after gaskets compressed over night.
New main seal, new front pump seal, new dipstick tube seal, new speedometer gear & seal, new shift lever seal, new extension housing seal(s), new governor cover seal..... verified no leaks on these.
When I fill it, I fill it with 4 quarts or 8 pints just enough to bring the fluid up to the cross hatch area, and I don't run the engine, and I let it sit overnight- sometimes 2 days.
It still leaks.
I always used aviation form-a-gasket with a non-rubber or non-cork gasket. I believe the gasket material is called Farpak. Make sure all bolts and bolt holes are cleaned. I use brakeclean to clean surfaces. Apply aviation form-a-gasket to both sides of gasket per its instructions and then install. Gradually tightened every other bolt working your way around to final torque value. I went 25% torque first time around, then 60% torque 2nd time around, and then went to 100% require torque value last time around. Let sit 24 hours before filling. I did my newer model 4-speed automatic about 1 month ago, and it as been fine. Hope this helps.
(Edit after researching your gaskets/sealants). This is the process that worked for me. Hopefully, it will work for you. However, maybe there might be a problem with the porosity of your transmission case.
Dave
Last edited by dash7510; Mar 16, 2023 at 11:33 PM.
Have you looked at the transmission lines at the case for leaks? That moroso gasket (if its the one I'm thinking of, the rubber coated steel one) goes on dry and should never leak. Thats a nice gasket. I'd look at the case where all the bolts go in also, maybe the case has a small split in it near the threads, but can't see that ever happening. The pan pitches forward, so any leak usually shows up at the front of the pan. Just my .02
Two thoughts here after all that business. One - The pan is distorted around the bolt holes from over torquing. Two - The case has a crack in it. You say that it leaks after filling it without running the engine. That would seem to be a pretty easy diagnosis as to WHERE it is leaking. Clean the area well with brake clean, fill to the level you say it leaks and then observe it very closely. Don't leave it overnight without checking.
Two thoughts here after all that business. One - The pan is distorted around the bolt holes from over torquing. Two - The case has a crack in it. You say that it leaks after filling it without running the engine. That would seem to be a pretty easy diagnosis as to WHERE it is leaking. Clean the area well with brake clean, fill to the level you say it leaks and then observe it very closely. Don't leave it overnight without checking.
Thanks for responding.
All 3 pans are straight- all 3 leak.
I repeat the flange straightening process for the stamped steel factory & Summit chrome pans- the Summit Aluminum is a thick casting- no straightening needed or possible.
If I leave it for only 1 night, no leak. 2 nights- leak.
The aluminum pan leaks primarily past the bolts.
I used both lacquer thinner and brakleen to clean- same results.
I buy brakleen by the case at NAPA. LOL
Is there some kind of glue I can use instead of gasket sealer products?
Is it the tiny "synthetic" molecules that are the problem?
I am clueless.
Never had this problem with the old fluid.
I have the same problem with synthetic oil on old school SBC oil pans.
Edit: it doesn't always leak at the same place. That rules out a cracked case.
Last edited by Tom454; Mar 17, 2023 at 10:04 AM.
Reason: Clarity
Has science evolved to the point that fluid will run uphill about 16 inches?
Capillary action has been around a very long time. Fluid will crawl up the inside of the case. If something happens that gets fluid into the breather tube, it can wick out.
Possible. Not common.
OP didn't really specify exactly where the leak is coming from, but if it's the pan, I gave up on pan gaskets a long time ago. Right Stuff just works too well.
Capillary action has been around a very long time. Fluid will crawl up the inside of the case. If something happens that gets fluid into the breather tube, it can wick out.
Possible. Not common.
OP didn't really specify exactly where the leak is coming from, but if it's the pan, I gave up on pan gaskets a long time ago. Right Stuff just works too well.
I always used aviation form-a-gasket with a non-rubber or non-cork gasket. I believe the gasket material is called Farpak. Make sure all bolts and bolt holes are cleaned. I use brakeclean to clean surfaces. Apply aviation form-a-gasket to both sides of gasket per its instructions and then install. Gradually tightened every other bolt working your way around to final torque value. I went 25% torque first time around, then 60% torque 2nd time around, and then went to 100% require torque value last time around. Let sit 24 hours before filling. I did my newer model 4-speed automatic about 1 month ago, and it as been fine. Hope this helps.
(Edit after researching your gaskets/sealants). This is the process that worked for me. Hopefully, it will work for you. However, maybe there might be a problem with the porosity of your transmission case.
Dave
I used both lacquer thinner and brakleen. Permatex Aviation was the first sealant I tried because it has worked for almost everything in the past. It hardened up, became brittle, and leaked. I tried it with several gaskets- no luck. I installed the Moroso gasket dry with the OEM pan and the Summit Aluminum pan- it leaked. Keep in mind that I never over torqued the bolts- always to 9 ft lbs or 108" lbs. After they sat for a while, sometimes over night or over 2 days, I re-torqued the bolts again to 108" lbs. There was always about 10-15 degree's of additional thread movement as the gasket compressed over time. The case is good.... the leaks aren't always in exactly the same place.
Maybe a silly question but are you positive that the bolt holes themselves are clean? E.g. that the bolts aren’t bottoming out? Take a pick out a mail and twirl it around in the holes, make sure you’re hitting bottom.
Maybe a silly question but are you positive that the bolt holes themselves are clean? E.g. that the bolts aren’t bottoming out? Take a pick out a mail and twirl it around in the holes, make sure you’re hitting bottom.
I checked all the bolt holes- some are thru holes, some are blind holes.
All of the bolts I am using are appropriate for the pan and gasket thickness used.
I match up the bolt & washer UHL to the pan/gasket on a 1 to 1 basis.
In a nutshell- factory bolts are 20mm UHL, Summit aluminum pan bolts are 25mm UHL due to the increase in pan thickness. That pan actually came with 25mm UHL bolts.
I use 20mm UHL bolts for both the factory stamped pan and the stamped steel Summit Chrome pan.
None bottom out.
According to the factory overhaul manual and the aftermarket overhaul manuals, spec for the 700R4 pan is 9 ft lbs.... which translates to 108 inch lbs (9 x 12).
I purchased an inch pound torque wrench years ago specifically for working on Holley carbs and transmissions.
According to the factory overhaul manual and the aftermarket overhaul manuals, spec for the 700R4 pan is 9 ft lbs.... which translates to 108 inch lbs (9 x 12).
I purchased an inch pound torque wrench years ago specifically for working on Holley carbs and transmissions.
700R4 Leaking
