Dana 18 Parking Brake Leak

I'm rebuilding my dana 18 transfer case. The parking brake mechanism has oil coating the inside of the drum, the shoes, and all the internals. I found this to be the case with the dana 18 in my other jeep. Is this a common problem? What can be done to remedy it? I'm replacing all seals and gaskets. Will that fix the problem or will it just delay the inevitable? Any tricks to keep the oil off the parking brake?

 

When it stops leaking, it's time to add fluid!

 

Well, some of the members have converted the drum brake over to a manual disk, seems to be a good way to go. You can get parts from willwood I think. If you do a search will find a write-up about this conversion.

One more suggestion if you are replacing the seals I would also go ahead and replace the intermediate shaft and all the bearing as well. It is not much more work and it will save you the time of doing it again in a year or two. I found this out from doing the same thing.

Good luck, oh yeah and it seems that most all Dana 18 t-cases leak to some degree so don't get to upset if it leaks.

 

I don't have as much experience with the D18, but the shim pack is the usual source of drips on the D20. The D18 has a similar shim pack, so you could probably do the same.

It seems that the new D20s would not leak - they would only leak after they had been taken apart and put back together. If you replace all the seals, and the pan is straight, you need to put a fillet of silicone over the edges of the shims to keep oil from seeping out. Let the sealant completly cure before you put oil in the case. Then it shouldn't leak. Maybe it was the paint that sealed the shim edges from the factory ...

This could be esp. important on a D18 with a drum e-brake, since the shims are right there.

 

use permatex form-a-gasket on the bolts.

 

I used the gooey red Permatex sealant on the bolts, copper spray on the shims, and a regular single lip rear output seal. I have very little leakage, maybe a drop every few days.

Some people use a double lipped rear output seal...I had one but ruined it trying to install it

 

I have read about using permatex copper spray on the shim pack, non hardening permatex on seals, especially the outside of the felt seal on the flanges and on the intermediate gear itself. Where it protrudes thru the case.
Several guys here have mentioned using RTV on the pan and tighten it part way, let it sit for a day to cure, then final tightening.
I am in the process of rebuilding a D18, and I put the pan on a piece of glass to check for straightness. Then used a ball pein hammer to dimple the bolt holes so they would pull the inspection cover (pan) evenly against the case.
Non hardening permatex on all bolts, and make sure you dont put a long bolt where a short bolt is supposed to go.
Oh yeah, put aluminum foil on the shift rods so you dont nick up the little seals. A little non hardening permatex on the last 3/4 inch of the rod before seating the seals. Dont forget the trick with the alignment bolts on top, and put the gasket on the tranny, not the t-case.