Rear main leak

Samson

Samson

Junior Member
I have had my '52 FORD FH engine hot tanked and completely rebuilt with all new internals. It has a stock bore with 4" MERC crank (it came with the block) and 8RT heads. The engine runs fine and now has about 400 miles on it.
That is all good news.
NOW FOR MY PROBLEM:There is a BAD oil leak from the rear of the engine.
This leak was from day one of startup in the car after rebuild. Since then the engine has been taken out of the car three times to replace gaskets and rear seals.It still leaked. With engine running,the leak area was inspected with a
digital camera with probe. The leak source could not be found. I have been told to run the engine to get the seals and run in and soaked.
The builder has been rebuilding flatheads for many years and has never had a leak from the rear seal area.
Are there any suggestions? I welcome any and all.
With all the experience out there someone must have an idea.
THANK YOU for reading this long thread. I have no other means to explain.
 
On the early 8ba's there is an oil galley plug over the rear cam idler gear cover which may be leaking ... the later 8ba's do not have it ...

picture.php
 
I had a similar issue in my avatar - turns out the crank was out of spec and had to be reground, polished, and new bearings installed. I have not re-fired the engine yet but my crank was definitely screwed up and the cause of the problem ....
 
Vergil said:
On the early 8ba's there is an oil galley plug over the rear cam idler gear cover which may be leaking ... the later 8ba's do not have it ...
Click to expand...

On the later 8BA's, it is under the edge of the oil pump gear cover
 

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Vergil said:
On the early 8ba's there is an oil galley plug over the rear cam idler gear cover which may be leaking ... the later 8ba's do not have it ...

picture.php
Click to expand...

Vergi. That's a really nice job of bending those big steel piped. I believe that is an early 1948 pickup 8BA style engine. It has a 1/8 pipe plug in the back above the gear cover. I've see 2=3 of those engine. They don't have a fuel pump bushing. That plug in the back is so the factory could drill a small hole through the casting into the main oil line to feed the push rod. They also had head studs instead of bolts. In 49 they used the bushing with a small hole to feed the pushrod and did away with the rear plug. A little triver. Walt
 
Walt Dupont--Me. said:
Vergi. That's a really nice job of bending those big steel piped. I believe that is an early 1948 pickup 8BA style engine. It has a 1/8 pipe plug in the back above the gear cover. I've see 2=3 of those engine. They don't have a fuel pump bushing. That plug in the back is so the factory could drill a small hole through the casting into the main oil line to feed the push rod. They also had head studs instead of bolts. In 49 they used the bushing with a small hole to feed the pushrod and did away with the rear plug. A little triver. Walt
Click to expand...

Thanks Walt, the stainless was a killer to bend, and good info you are sharing ....
 
check the rear cam cover plate, have had that happen, I thought the rear main or pan gasket was leaking, it turned out to be the plate covering the back of the cam
 
Could also be the rear seal retainer....perhaps cracked? This part (8BA-6335) was made from pot metal. We reproduced them in solid aluminum. Check the easy parts first that the others have already suggested, but you may have to drop the crank if nothing else proves to be the culprit.

Please post the final resolution to the problem when you get it figured out.
 
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Just started up my 38 for the 1st time and a leak from top back above bell housing. Turned out to be bent flanges on the fuel pump riser was slightly bent and allowing oil from the oil filter return line to leak past the gasket.
 
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