I want to check the oil pan gasket for a good seal, specifically the rear 3 hole gasket, before I put everything back together. The engine is in the car, 1979 TA 400 4spd. How much oil must I put in to get the oil level above the height of the rear rubber seal?

I want to check the oil pan gasket for a good seal, specifically the rear 3 hole gasket, before I put everything back together. The engine is in the car, 1979 TA 400 4spd. How much oil must I put in to get the oil level above the height of the rear rubber seal?

There's not supposed to be so much oil in the pan that it reaches the rear rubber seal.

Also simply putting oil in the pan and checking for leaks probably won't help much. Crankcase pressure from running at wide open throttle tends to push oil out through gaskets and seals. Therefore the best way to check for leaks is after running the engine.

The 3 hole rear seal is notorious for blowing out after the engine is in the car and has run a couple of times. I've had good luck using the 3 hole pan with the cork gasket but the
rubber one just blows out. This issue has been discussed at least a couple of times, you might want to search the archives.

JJAKE,

Just completed a complete rebuild on a 455 and the only problem I have is what your concerned about. The rear rubbers seal slipped after installation and now I have a leak. My plan to fix this by doing the following:

Remove pan and gasket and replace the rear rubber seal on the pan buy using hi temp. RTV on the backside only. Placing the pan back onto engine and installing the two rear pan bolts only to allow it to set up. Upon setup, inspect the seal for proper placement. Replace the rest of the gasket and apply sealer on top of rubber seal and tighten all bolt to spec.

Can't tell you how disappointed I was when this problem happened. Luckily it's the only mistake I made on my first rebuild.

Regards,

Sounds like a plan, I'll give it a try.

I agree, the 3 hole rubber gasket can squeeze out after a while, so a leak check after a rebuild may be n