Hello all , just spent better part of the weekend installing a new rear main seal and pan set on my 63 390 , all though it slowed the leak down considerably , l still have a drip , l used a Felpro seal , l did not put it in backwards and cleaned and torqued everything, is there a brand that is better then what l used ? , any input would be appreciated, thanks .
Did you compare the new seal to the old seal? Last time I checked a few years ago, Felpro had the wrong seal. They had the 62 and earlier seal as the same for the 63 and up. The 62 seal is smaller and leaves a gap between the halves.
Best Gasket has the correct seal. I have put in a few, and a few drops of oil is to be expected.
thanks for the reply , yes l did compare the two , looked identical , when you say a few drops is expected are you talking dime size spot on the ground over night ?
Have you had any additional feed back on the rear main seal you installed that had a —one inch seal off set — off of the center line of the rear main bearing cap joint ?
That repair might be the first seal install that has not leaked ( at least initially ) but wondering if you know anything new about how that seal repair is holding up after some additional miles on it
In almost every case on this site the most that can be expected is that there will be a small amount of engine oil leaking from the seal that happens only when you park the car and the engine cools completely off for a long period of time leaving a 6 inch oil spot ( approximate in a pan under the engine ) but no oil staining when the car is used and out and about ( and engine is at operating temp )
A very small amount of engine oil looks like more than it is —when forming a spot in a drip pan or on the ground as it does spread out a lot
It is manageable if you park over a drip pan and keep an eye on it as the amount of oil has stayed the same and is small and acceptable ( non would be better !) until we find a solution if there is one
My own oil seal leak in the drip pan has been reduced some since I stopped using Mobil Syn motor oil ( for about 30 plus years ) that no longer meets my flat tappet cam needs ( formula changed ) and have gone back to using a conventional 10w - 30 Castrol motor oil with a Rislone zddp additive to meet my flat tappet cam needs and be staying with the 10w - 30 weight oil the engine requires
Some other gasket seal leakage has improved as well going back to the conventional oil which has worked out very well for my own needs
We seem to be doing the best we possibly can with some leaking after a rear main seal repair until hopefully something changes for the better in the future to correct the issue
Tony, my rear main seal started leaking, so I can not claim a drip free rear main seal.
Thanks for your feedback on your rear seal repair
Was hoping you might have solved the problem for all of us
Back to the drawing board— as a bit of a leak from this seal looks like something the owners of our year Cadillacs will have to live with
Based on the fact that all the rear main seal repairs done on this site over many years have leaked wether done with the engine in or out of the car you should evaluate the amount of oil you are loosing from that seal and live with it if you can —if it is a reasonable amount- and only doing it a second time if it is leaking more than discussed or reasonable
You can pretty much count on it leaking after your second attempt I am sorry to say being on this site many times daily since 2006
That is my best suggestion based on following this repair over many years and this repair is no walk in the park ( a hell of a lot of work )
The ball is in your court
I hope I just may have saved you many hour of labor
My 64 convert came home off the showroom floor in 64 and there was no sign of any oil on the floor for many years so you sure do have a point there
Hoping your knowledge and experience will help to resolve the main rear seal leak issue and be helpful for many in this community
I am only letting you know the results of the half a dozen or so attempts to solve the problem with no positive results that were posted on this site including your attempt
Some have indicated the wear factor regarding the condition of the crank cap bearings and any slack there may be a factor in the rear main seal getting damaged and leaking or being damaged by that movement
Then again Jason Edge who is maticulas at all he does ( and our Web Master ) rebuilt his entire engine ( all details posted on this site ) so all is brand new regarding his cranks condition still has the same rear main seal leaking as explained thru out this thread
Thank you very much for what you have added to this discussion and look foward to your future results due to your background
We need more men with your kind of background experience on our site
I do understand your feelings about oil leaks
Looking foward to hearing back from you in the future regarding the seal repair