Leaking rear main, but coolant too??

[adavis]

I purchased my '31 two months ago and it had not been driven more than 5 miles in the last 45 years. It has a 1935 Diamond block B motor with the stock transmission. I drove it on the trailer and drove it into my garage when I got home. I drained the oil (black but looked fine) and added fresh with a quart of Seafoam. I changed the coolant...which was bright green. I drove it to last month's car club meeting and had no problems going the 13 miles there, but on the way back the fuel valve under the tank plugged with debris. I got the car home with no other problems.

On Sunday I drove the car to another car club meeting and it seemed to do fine, although did notice some smoke in the cab when ascending any hills but could not see anything behind me. I'm not sure if it was exhaust or not, but I do see that I have a leak around the joint where the pipe meets the manifold. It still seemed to run alright with no power loss or bad sounds.

When I got home I pulled into the garage and parked it. I came back out an hour later and there was a decent puddle of oil at the back of the engine, under the hole in the flywheel cover. I initially thought that my rear main seal was bad, until I figured out I don't have a rear main seal in my engine. Now I realize that I will need to check the rear main bearing to see if it has any shims left that I can remove to try and stop the leak, but is there anything else I should know or be aware of that could cause the leak? Its probably only a tablespoon of oil and the place I talked to said Model A's leak by design, but should I worry about that much oil?

And here's my real question. There is fresh green coolant drips on the bottom of the bolts holding the front wishbone ball cap. Not oil/coolant mix, but pure green coolant. I also see some signs of coolant drops in the puddle of oil, but the dipstick still shows nice and dark oil and the coolant in the radiator looks good. How in the heck did bright clean antifreeze get on those bolts? The oil pan is dry front to back so it didn't creep back from the radiator and I don't see any wetness on the upper end of the engine on either side, front to back. I'm just curious if anyone else has seen anything like that and if it means something really bad. Thanks for any input, and if I need to clarify or give more information please let me know.

[AlanD]

Consider this theory, could the "fresh green coolant drips on the bottom of the bolts holding the front wishbone ball cap" be a result of overflow being blown back as you drive? If its not overflow, it might be a leak somewhere.

[adavis]

Yeah, I thought the same but the oil pan is dry front to back. I would think if it was from the overflow I would see a wet pan too.

[bogdonj]

Have you tried re-torqing the head?

[TinCup]

I had the same thing happen to me and it turned out that the two bolts at the top of the flywheel cover had been heli coiled and when they did they drilled into the water jacket. I would see water in the same place you are descibing. They would only leak after long trips. I used a little Bars Stop Leak and that took care of it.

[adavis]

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Nope, I haven't touched the head yet but my new gasket set just arrived so after my club's show next weekend I'll probably tear into her. I didn't expect to find coolant at the back of the engine, but at least someone else has found the same thing so I know I'm not crazy. I'll post after the engine is out if I find anything interesting.

[verdirick]

Check to see if the rear main cap mates perfectly to the block. You may need to take the cap to a machine shop to check to make sure it is true (absolutely flat) so that it mates to the block surface so that no oil can be pumped between the block and the cap. Might sound crazy but that is what I found when I first ran my B engine. After I had the cap trued, solved the problem. Ran for 40,000 miles without a problem until I attempted to pull a shim and wo la what do you think happened. Rear main again leaking. B's have the problem as they have full pressure on the mains...... If the cap isn't true, the modern seals are a mute issue.

[30Tudor]

It's amazing where the coolant will migrate from. I had a small leak from my water pump which you could barely see. The antifreeze ran down onto the lip of the head gasket. From the front of the engine it ran along the head gasket all the way two the rear of the where it ran down and ended up on the flywheel hole cotter pin and then onto my floor. Took me a long time to figure out.

[columbiA]

I had a small coolant leak at the bottom of the water jacket below the water pump.It would travel along the pan rail & drip off the bottom of FW hsg.I ground the paint off the crack & put some JB weld on it & its fine now.