Oil leak on rear of engine
 

I have a 1938 Ford Pickup 1/2 ton, flat head v8. When it in the shop running, no oil leak, If you run down the road about 2 miles and back, put in the shop, there is a large oil leak on the floor, coming out of the bell housing, can it be a rear main seal or a gasket on the back of the engine? It only leak bad after a road test, not running in the Shop? Thank You

Re: Oil leak on rear of engine
 

>>>there is a large oil leak on the floor,>>>


How large? There's a labyrinth seal, not rope or rubber. Probably overfilled and some blowby. Try using 4 or 4.5 quarts, not 5.

Re: Oil leak on rear of engine
 

too much oil, what weight oil? 20W50 is best

Re: Oil leak on rear of engine
 

I used 20W50 oil, still leaking, The oil is at the full mark, I think the rear main is dry up from sitting for 25 years, Thank's

Re: Oil leak on rear of engine
 

Dont always go by the dip stick how much oil did you put in it i agree with woodyman good friend of mine had a similar problem with his 35 v8 p up then he drained and only put in 4.5 quarts problem solved also he has no oil filter

Re: Oil leak on rear of engine
 

>>>I think the rear main is dry up from sitting for 25 years,>>>


No. It's a pot metal labyrinth seal. Nothing to dry out. Suppose it could break though.
https://reds-vintage-parts.com/red-s...ls-janfeb-2003




https://www.fordbarn.com/forum/attac...1&d=1681572994

Re: Oil leak on rear of engine
 

Make sure your breather cap is not clogged up. That can pressurize the engine and blow oil out.

Re: Oil leak on rear of engine
 

You sure it’s engine oil and not transmission oil?

Re: Oil leak on rear of engine
 

It only took 4 qt of oil, it has no oil filter, oil coming out of the bell housing by the cotter pin, it only leak when I road test, when in the shop running, no leak, it a big oil leak?

Re: Oil leak on rear of engine
 

How large of a spot is it leaving on the ground? A little spot a couple inches or less in diameter or a puddle? That cotter pin is there because Ford expected it to leak a little.

If it’s sat for 25 years, I’ve heard of the cork oil pan gasket under the rear main drying out. That could contribute to a leak.

Re: Oil leak on rear of engine
 

Make sure the crankcase vents are open as well...the one down at the front right side of the oil pan and also at the fuel pump stand.



Terry

Re: Oil leak on rear of engine
 

>>> I’ve heard of the cork oil pan gasket under the rear main drying out. That could contribute to a leak.>>>


Agreed.This cork strip can also easily get misaligned or twisted out of place upon assembly. Then leak badly even brand new. Glued a neoprene strip to mine before assembly instead of the cork composite. VanPelt panphoto shows where strip is placed.


https://www.fordbarn.com/forum/showthread.php?t=168956


https://www.fordbarn.com/forum/attac...1&d=1681676578

Re: Oil leak on rear of engine
 

I have in the past experienced that pot metal insert being broken/crumbled, which resulted in big oil leak.

Re: Oil leak on rear of engine
 

Thank You for all the reply