Hello all, I have a 1995 350 with a 7.3 with a massive oil leak. I have narrowed it down to the front driver side of the motor. I can't tell exactly where it may be coming from do to the fact that the frame rail is in the way and it dumps about 3 gallons of oil in 2 minutes of run time. It isn't leaking while parked just when it is running. I recently sealed the oil cooler and it appears to be coming from further ahead on the engine. Is the a high pressure line in that area the is prone to leaking or could it be coming from the loop? Any advice would be appreciated since it is getting expensive (cost of fresh oil) tryigt to diagnose this.

 

Are you sure you didn't damage to oil cooler O-rings when installing them? They need a ton of lube.

 

Either that or the front seal to the block. First time I put mine on I didn't have but one hole in the gasket lined up and I had a massive oil leak.

 

I am hoping i didn't damage the o-rings because that was a bear of a job. The leak also seems further ahead but I can't tell for certain. Is there any way of telling without taking it apart and just redoing it?

 

The front main seal has leaked since we bought the truck but it was incredibly slow. The reason I haven't changed it is everyone says it is a lot of work so until it gets really bad not to worry about it. If it is leaking would it squirt out and wouldn't it leak when it is parked. Just trying to not tear the whole truck apart just to find out that I could have fixed the problem with just a hose clamp or something. I'm new to the whole mechanical thing but the diesel shops are just getting to expensive around here.

 

One other thing I have put about 3000 miles on the truck since i sealed the oil cooler

 

Start the truck, and get under it with a light and see where the oil is coming from. If it is leaking that bad, it should be pretty easy to tell where it is coming from. Did the leak get worse after the cooler repair? If so, that is a pretty good indication something went wrong on the overhaul. I use Vasoline to lube the O-rings when I do an oil cooler repair. Lube the snot out of the ring, install on the main body, coat them again, then place 1 cap on a board the other cap on open end up, put the main body in the cap, and put the other cap on the body. Then I use my body weight to push down on the assembly while "walking" the cap. Usually you can feel when the cap pops into place.

 

Don't forget the oil rail plug at the front of the head. Kind of hard to see with the AC and power steering kit in the way, but they can leak a ton when running. Much easier to fix than the oil cooler.

 

I'll quote myself. I didn't explain very well. I meant to say the front oil cooler seal to the block, two bolts. I made the mistake and let the seal move and when I put the bolts in only one bolt went thru the hole in the seal and the other bolt missed the bolt hole in the seal. The seal had slipped down and the bolt missed the hole. Like you said, its hard to see in there. When I discovered my mistake I loosened the one bolt I had in position correctly and took the other bolt out, moved the seal into place and made sure the bolt went thru the hole in the seal. No more leak.

 

Good catch I didn't even think of that. Reps tried, I'm in reps jail. lol

 

Can I get to the oil rail plug without removing the AC and power steering?

 

I don't think so.

 

I've been under it but it leaks so fast I can't find it before I loose all the oil. I was under it yesterday and had someone else start it and it dumped 3 gallons in about 3 minutes
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The AC can just be unplugged (electrical) then unbolted and move it to the drivers side fender area, just bungee tie it to the hood spring. The other items in the way are on a single bracket, I think four bolts holding that bracket to the block. Remove the top three and loosen the bottom almost out but leave some threads in for alignment when reinstalling. The entire bracket will pivot forward for easy access to that area. Of course the belt has to be removed.

This is assuming it's the front drivers side rail plug ... but loosing that much oil so quickly it's hard to believe the truck would run with the rail plug o-ring leaking, but maybe.

 

What Jim said. Three gallons in 3 minutes is a crazy big leak. I've had both my oil rail plugs go out on my driver's side head, and while messy I don't think it reached 1 gal/minute bad. Hard to believe those injectors would have adequate oil to keep things running.