Hi everyone, I have recently purchased a 78 f150 4x4 with a 79 460 engine. The guy I bought it from said it had a 7 quart oil pan from a van. He also told me he used a new style 1 piece pan gasket witch apears to be leaking from the rear area near the main seal. I'm hoping its not the rear main. Are the 1 piece gaskets better than the older 4 piece type? How can I tell if it's the rear main seal or just the pan gasket without removing the pan. The leak is in front of the auto transmition plate. The pan numbers are E7TE 6675 bb, is this a 7 qt pan from a van? Thanks ,
Carl

 

Have you tried to tighten the pan bolts a bit? Not, overtightening to squash the gasket too much, but sometimes the pan bolts can loosen. But, where the leak is located, it very well could be the rear main seal. How old is the gasket?

 

One way to check would be to degrease the area very well and then to put an ultraviolet dye in the oil. You can pick these kits up at pretty much any parts store (Napa) etc. But i am with Bucks77, by the location i would almost lay money on it that it is the rear main. I have had nothing but problems with 460 doing the same thing and 2 out of 3 times it has been the main seal.

 

The engine was rebuilt a year or two ago but was not put into the truck untill 5 mo. ago when the truck restoration was completed. It has about 800 mi. on the motor. Is the rear main hard to change?

 

The rear main involves taking the pan and the rear main cap as well. Those pans (rear sump) are not 7QT pans, but 5 plus 1 for the filter.

 

its not fun put it that way, you have to drop the pan and remove the rear main cap, if your lucky you can sometimes get the old seal out and install the new one without removing the crank. I have seen this work on other engines and I have been able to install a seal this same on my 460 however, for the amount of work and aggravation, plus it started leaking again in about 6 months i would personally just drop the crank. At least that is what i did the last time and so far a year and a half later it isn't leaking "knock on wood". I would personally get some more advise on the change without the removing the crank as I have only done this once and it wasn't a pleasant experience for myself, but someone else may have some tips.

 

I guess with these old trucks it will be much easier to just pull the motor, turn it upside down, take the pan off and try to get the seal out without taking the crank out. Like FRITZ77 said, doesn't always work. By having the motor out, you can make sure it's done right and if you need to pull out the crank than you'll have the motor out.

 

I have actually seen the seal removed in this manner without pulling the crank while the engine is still in the truck, you just have to loosen all of the mains to relieve the pressure on the upper half of the seal, you just don't remove the caps completely so that they will hold the crank in. But like I said, it's a pain and it doesn't always work.

 

I had a remand motor that leaked out the rear main seal almost immediatly, and smoked when started up. After about 15K, the smoking stopped, and the leak went away. This was a F4TE 351, so it had a different seal. I say drive it, and if the leak does not go away within another 10K, run some penzoil and some fix leak in a bottle. I like the idea of the one piece rubber seal. Trying to get those stupid end seals to stay put is a pain in the neck for me. There is a possibility that the oil pan needs maybe 1/4 turn more on the bolts, OR somebody tightened the bolts too much, warping the metal of the pan, and possibly (unlikely) causing your leak at the very back of the motor.

I say ignore it for now(park out in the street in front of a neighbors house you dont like), see if it worsens or over time gets better.

 

Not to offend you Masterbeavis, but I personally would not use a stop leak additive in an engine that only has 800 miles on it. I think that this could be bad for the bearings and the piston rings with their break in. I do agree with your idea to check the pan bolts, however, i would actually drain the oil and do an oil change if you haven't done so on the engine since it was overhauled, with the oil drained, i would loosen the pan bolts and torque them to the OEM specifications.

 

I said

The idea behind my advice is to give the seal a chance in hell to maybe swell or wear enough to seat properly, then dump stuff to make the seals seal. After 10K, if the rings have not seated properly, you have issues worse than an oil leak. Bearings do not need to break in if properly clearanced.

If the rear seal is installed proplerly, with the ends siliconed together and sticking up and out about 3/16", I don't see how it can leak, unless there was excessive wear on the crank in the sealing area. I never was an engine major, or have any credentials to show for, but in theroy its hard to screw something like that up. The seal even comes with directions inside its packaging on how to install it. Heh, ever notice in the Fel-pro box that some of the gaskets have ford part numbers cast into the rubber?

 

My apologies, i misunderstood your post. But you are absolutely right, after 10k it wouldn't pose a problem to use the additives. I do know that bearings do not need to broke in also. I have also noticed the ford part #s on fel-pro gaskets, I found it rather interesting but have not done any research. I also agree that it is difficult to screw up a main seal installation but I have seen it done and have done it personally with the install while the crank is still in the block. Another reason for leaks, (and this was on a reman) that I have seen personally, (cousins mustang) was that the seal was installed backwards, the lip was facing the wrong way, don't ask me how it happened in the production plant but it did. Regardless, their could be an infinite number of reasons why the seal would leak.

Sorry if I offended you in any way, it was just a simple miss reading/understanding of your post.

Sorry again

 

I aint worried, it happens. The seal going in backwards escaped me, that could be the problem. It's easy enough to pop the pan and the cap to check it out, especially because the pan gasket is the rubber one piece job.

 

That is true, and if the initial break in oil change hasn't been done (i've always been told 500 miles) that would be a good time to pull the pan and check since the oil would be drained already, However, if it has been done and it isn't leaking a to terribly bad i would wait until the next oil change is to be done. Also, synthetic oils tend to leak more so if synthetics are running it might not hurt to just use conventional oils.

 

The initial break in oil change should happen the minute you are done breaking in the cam. Then at 500 mi +/-.