Originally Posted by
bmorgil
I have attached the procedure as outlined in the General Service manual for your F head. They direct you to install the mains torque the caps check the end play and then as the last, install the Rubber Packing's "Plugs".
The plugs are supposed to be a prefigured correct length. You are to insert them into the assembled cap and block, push them down, and not trim them. They are supposed to stick up about 1/4" once they are pushed in all the way down.
I had two problems. I could only push them down about 3/4 of the way down. I tried oil and that did not help. I then removed the main cap and inserted the plugs ahead of time. I used black silicone very lightly on all cap to block surfaces. I used a small amount on the plugs to make them slide a little easier. I then fit everything together at once. Pushing the cap seals and all into place. I then had about 3/8" of plug sticking up. I took it all apart again and measured the plugs. About 1/8" two long and probably a little fatter than the originals. I reassembled using the same process of inserting everything together, and trimmed the rubber to 1/4". I applied 5 lbs of air pressure to the assembled motor to insure there were no leaks. The rear cap, pan and main all sealed up nicely, 150 miles now and the assembly is leak free!