Case through bolts leaking?
 

Process of elimination has led me to believe that one or both of the case through bolts behind the oil cooler is leaking.

Symptoms: leaks a steady drip from the groove in case on the side of the lower oil cooler seal only when running, new oil cooler seals (did this last winter too, thought I had pinched one or something), cleaned and pressure tested the cooler, replace the t-stat o-ring, pressure sender and breather hose and cover gasket.

Switched to carbs so I can now access the back of the shroud and top nut easily. Is there a downside to removing the cooler and removing one nut at a time, cleaning the area, using some silicone with a new o-ring and re-torquing to spec?

This is the last remaining known leak and it's driving me crazy!

Sounds like a good plan. You need to be very careful doing this as those studs can pull and then you're f***ed. Just torque them up very gradually and if it were me I'd under torque them slightly. Good luck.

-Andy

You're confusing the through-case bolts with the head studs. The first post was referring to the through-bolts.

You can indeed go through and remove and reinstall each one, putting in some black silicone (which I recommend anyways on assembly) - this should guarantee no leaks. Be sure to properly clean the area so that there's no oil residue to interfere with the silicone.

Removing each bolt one at a time might have an impact on the case half seal, although I doubt it...

-Wayne

Thanks. Since I had cleaned the case really well over the winter I hope to be able to tell which of the two nuts behind the cooler is suspect. I'll remove one at a time, clean and silicone them.

The motor was rebuilt about 20,000 miles prior to my purchase and I've had this leak since buying the car. I've taken care of all the other usual spots so hopefully this is it.

Actually I don't think I'm the one confused. The "through bolts" that have nuts hidden by the oil cooler are studs. They are threaded into the case next to the number one main bearing. Being as this is a Mag case they can pull just like any other stud. If you are indeed talking about bolts then yes there would be no worry, but the dome nuts under the cooler are not attached to bolts.

-Andy

Andy,

I understand these are studs, with the acorn style nuts. Will take the necessary precautions to keep the studs from pulling.

Thanks for the heads up.