Rear main seal leak 351 cleveland

[EBSTANG]

oil pressure does not cause rear main seal leaks, but crankcase pressure can. I had mentioned eariel to make sure the PCV system was in good shape for this reason. All engines have blow-by to some extent, and if the PCV system isn't proper, the front and rear seals will leak. When I bought my car, the PO had replaced the breather on one valve cover with a sealed cap. At higher RPM it would spit out the oil dipstick and the PCV valve and spray oil everywhere.

It is hard to drive at low RPM on the interstate with 4.10 gears- my buddy who drove me to pick up the car got a nice misting from driving behind me. LOL

Now that's funny!!! lollerz

That's where I would look the closest. Glad to see someone else experienced "Dipstick Syndrome"! Always heard size matters, so when I was offered a larger 4bl from a 428 Police Interceptor to install on my 71 "M", I jumped right on it. My original setup had a hose from the PCV valve(L/F valve cover) to a stub on the rear of the carb. The 428 carb didn't have that fitting, so I just removed the hose and valve. That's just more junk under the hood, and that's why they made regular oil filler caps, right? And that would also make me a member or the throw away club like my buddies that were throwing away all those Rochester carbs and rev limiters.

Didn't take but two days and I had oil everywhere. Oil was seeping from the rear and front seals, and the dipstick was actually pushing out of the tube until the hood stopped it. I thought the car was possessed. When one of the shop techs looked at my car and saw what I had done (can't print everything he said) I was made to understand "Crankcase ventilation"! :whistling:

 

[Jeff73Mach1]

He was in a Jetta, he deserved it. Our adventure when picking up his 911 15 years earlier resulted in me passing him in my slightly souped up 95 Mustang GTS at a speed in excess of 150 at night, he was following a state trooper who was running about 100. I did pull over when the lights came on and I did not go to jail or lose my license. I behave much better these days

 

[Carolina_Mountain_Mustangs]

I will throw this one out there since I know of one that happened. It was a GM engine but Ford does the same. When they use twin V-8 engines to drive a boat they have one engine running one direction and the other is reverse. This guy had a GM engine that he could not get the rear seal not to pour oil. He had got the crank from a supplier ground and he just put it in. After much pain and many tries someone noticed that the hash marks on the crank were reverse and was pushing the oil out the seal instead of into the case, Marine crank for reverse rotation. Ford did make lots of Marine engines could it be that the hash marks are backwards for reverse running engine? One in a million chance but check those hash marks. They should be pushing oil in not out.

This was common in the 427 engines also.

David

 

[piper62j]

Just a thought.. The oil pressure sender sitting in the back of the engine could be leaking.. I've seen this over the years..

 

[piper62j]

Paul.. Read Machclone71 latest update 6/2/16 about how the high oil pressure was causing the rear main seal to leak.. It was apparent the incorrect oil gallery plug bumped the oil pressure up to 100psi causing the rear main to blow out. After he discovered the problem, no more leaking rear main seal..

As I stated in the original postings, high oil pressure can in fact cause the rear main seal to leak.. I hope this helps you to understand more about these older cars and the problems that can arise from poor knowledge about how to maintain them correctly..

If oil pressure can have an effect on a rear main seal leak please

educate me on how I have never heard of this.

Paul