Rear Servo Leak

Yo Dudes.....


Just got my engine runing today after swaping in the new C4 tranni.

Looks like the rear servo is leaking. Won't know till I clean up the fluid, the headers cool down, and I can jack the sucker up...

But everything was great till I put it in gear, then lost about 2 quarts in 10 seconds. I looked several times, everything was dry before putting it in gear and had the fluid to the correct level.

I have a question about the rear servo cover. Is the square rubber gasket supposed to be at an offset to the cover, or should it sit square with the cover? Like a dimond shape sitting in the cover groove, or flat to it's surface? I have it sitting like a dimond. That is the way the old one was when I took the cover off.

Secondly, is there different seals (codes)? I noticed a series of colored bands on the rubber gasket when putting it in. I wrote down teh colors, but now can't find that note I wrote. I think Yellow White Green??

Thanks

I think I have solved my own problem....

Yes, the rear servo cover is an issue with the gasket I used. The one that was originally on there. 68 C4 was dry-totted to the cover, so when I took the cover off, I had no gasket. The gasket I got in the TCI kit was the wrong gasket. TCI kits SUCK.

So, I took the servor cover off of the old C4 I own and I will be using that one. Cover and all.

The square ring is supposed to sit flat on the cover. As you tighten it the gasket is forced into the chamfer to make a good seal. When you pull an old one out they are triangle shaped - because they are forced into that shape. If you have issues with leakage then use a thin coat of lock-tite "Gasket Maker" onthe square ring before installation.
There are different square seals that are in the kit but only one fits the rear servo cover.
The rear servo only gets pressure in reverse and manual low. (unless you have an aftermarket valve body)
With manual aftermarket valve bodies it is usually the same but it can also only be pressurized in reverse.

Thanks for the reply Paul, I will be looking into this tonight.

You don't mean Silicon gasket sealer...do you?

All better now....

I used the servo cover from the tranni I just took out of the car, with the old seal.

Closed it up just fine. Ran the car for 20 Minutes, and tried the gears a few times....reverse and forward

Pain in the BUTT 66 Mustang though... There was no room to work up there, so I had to drop the brand new 2 1/2 inch pipes I just put in, and drop the rear tranni mount, lowered the tranni enough to get to the servo cover.

The header pipes were still in the way, but I was able to work around it.

Mike,
NEVER use silicone sealer on an automatic transmission. The lock-tite "gasket maker" is a gel that seals when you exclude oxygen (anarobic sealer). It forms a pliable film that is easily removed but seals even under oil. It is all I ever use.

I did not think you meant silicon... I was sure that would not be a good thing, since I think the fluid would seap past it anyways....
I did not use any gasket sealer. I think it will be fine, since I have never used any gasket sealers on these covers in the past....

A side note: I have the overflow tube above the servo cover. It had a tube clamp on the top bolt on the servo cover.

I think that is where the leak was. I noticed with the tube clamp on there, that bolt was not as tight, because wen that bolt goes tight, the tube clamp calked. To keep it straight when I have the motor out, I did not tighten that screw as much.

So, I did not install the tube clamp, and I was able to get that screw a lot tighter then it was.

You can use a washer to keep the clamp straight if it is important to you. Most just tighten the bolt down and let the clamp rest where it will.