SanDiegoPaul

My 388 just passed the thousand mile mark! :party:

However :bb the darn Turbo-350 pan is leaking again. :bs When we routed the exhaust behind the Hedmans, we hooked up the EFE valve on the right side collector.

The prob is that these headers hug the center so much that the EFE valve is VERY close to the transmission pan. I rebuilt the trans just before the new engine went in, and there was no leak with the factory exhaust. After about 800 miles on the new motor, I put another pan gasket on it and relieved the pan to allow another 1/16" or so clearance but now it is leaking again a couple of hundred miles later.

What's a guy to do??? :hat :smash:

Alwyn678

Put on a new gasket what kind are you using?? i have a cork one and it has never leaked...However I wet the gasket before putting it on..so it seals better

mrvette

I HATE dipstick tubes, engine or tranny,....home of the damn LEAK!!!!!

having that rant over with....IF you are sure it's the pan....

I have had GOOD success with just putting RTV on it NO gasket...let it sit overnight...and then fill with fluids again....

make sure EVERYTHING is clean as hell and complete degreased and I mean completely...use carb cleaner on a HOT tranny so it evaporates better....

bolt the SOB on and forgetaboutit....

GENE

SanDiegoPaul

make sure EVERYTHING is clean as hell and complete degreased and I mean completely
---------------------

Yea it was clean! Heck it had just been done. The gaskets used are FABRIC style not cork. Does that help? :mad

TedH

I had my exhaust pipes bent away from my 700R4 to avoid this. My 3" header collectors are right at the torque converter cover/starter area. With the pipes bent away and then straight back, I get about 1-2" clearance from the sides of the trans pan (still have to use a wrench on some of the pan bolts as the pipe gets in the way). I just fixed a selector shaft seal leak. I'd recommend you verify the vacuum modulator, kick-down, dipstick and selector shaft seals and exterior of trans lines at transmission are dry. I thought I had a leaking pan gasket for a year until I found the leaking selector shaft seal. Helps to have a mirror that you can reflect from above the transmission pan case/rails. I dried the transmission case rails off and then waited/watched for leak to form (right under the selector shaft).

Good luck! :seeya


[Modified by TedH, 3:13 PM 1/29/2003]

Gary79

no expert here, but i have always been advised NOT to use any RTV or sealer on the gasket. if the smallest piece of RTV breaks loose and floats around in that tranny, it could clog up a passageway. the main thing is to get the pan clean and straight and the mating service on the tranny clean, and to NOT over-torque the bolts. i don't think the gasket type, cork or the other makes much difference, although cork may be more forgiving.

SanDiegoPaul

what about a high-temp gasket? :hat

Chris69

I replaced my leaking 700R4 gasket with a Fel-pro... the one with the 'thread seal' feature. All that really means is that the gasket's bolt holes are slightly smaller than the bolt threads, so you get a good seal. Not sure what kind of material it is, but it seemed somewhat rubberized. So far no leaks, but still too new to know if it will last.

8T1-7T9 BIONIC VETTE

The key word in keeping the trans gasket from leaking is "Torque"......Proper torque.....I've watched many guys down at the hobby shop over tighten their trans gasket....then when the leaks appear....continue to tighten down on the gasket.....By the time they request my help...They've ruined the gasket....I tell them to go get another gasket and tighten only to the specs. Their smile indicates another happy camper as they drive off into the sunset. :seeya Cappy

MRZ28HO

That's gotta be the most understated statement. I used to hand tighten those bolts, after alot of oil leaks, I decided to try those puny torque specs ... they work! :yesnod:

redwingvette

My book says to use 14ft/lbs. Does that sound right to you guy's?

Smokehouse69

TH350 pan 130 in. lbs.
TH400 pan 12 lb. ft.
According to the 1969 Chevrolet Chassis Service Manual

SanDiegoPaul

Yes 14-15 foot pounds is fine. Mine still leak! Thanks for all that suggested making the torque correct but YES IT IS.

The problem is that the EFE valve is cooking the TH350 gasket. I am hoping there is a replacment that will take the higher temp :rolleyes: :nopity :cuss :nonod:

SanDiegoPaul

ttt :party:

8T1-7T9 BIONIC VETTE

I take this post to mean your leak no longer exist? :party: :seeya Cappy

SanDiegoPaul

The problem is that the EFE valve is cooking the TH350 gasket. I am hoping there is a replacment that will take the higher temp

In response to the last Q yes, the darn leak still exists! :smash: :smash:

Is there a high-temp gasket?? HELP??