Brakes-Line Leaks

[selwyngent]

I'm in the process of rebuilding my braking system and noticed gear oil leaking out of the mounting holes for the rear brake lines. Is this normal and what type of sealant is recommended?

[Don Henschel]

Is the oil?(brake fluid) coming from where the brake line screws into the cylinder or is it actually oil seeping down from the axle and running down your brake cylinder?
If it is coming from the fitting, there are no sealants used here. The brake line fitting could be loose or is your brake line rusted and leaking. If you try tightening the fitting make sure you use a very good wrench (preferably a line wrench or a flare nut wrench) so you dont round off the fitting. If its gear oil and not brake fluid, your axle seal is leaking. If you can take a picture and post it.

[selwyngent]

No, from what I can tell it's axle oil leaking from behind the brake line mounting clips that mount to the upper portion of the axle tubes and that run the brake line along the top length of the rear axle. I removed the brake lines to clean them out and noticed that the bolts for the mounting clips seem to just screw straight into the axle tubes, so my original question was concerning a sealer to use for the mounting clips. Thanks

[Barry Wolk]

I would think that an O-ring that tightly fits the screw would smoosh down and fill any voids.

[Don Henschel]

http://www.wentite.com/jscs/mf/Ultra_Blue_TRV_Silicone_Gasket_Maker.pdf
or
Loctite 515 gasket eliminator.
Remove all oil and dirt from the threads of the bolts. Brakeclean works good for this.
Apply the silicone or 515 to the threads (dont use too much!-about as much as a large match head maby a bit more).
I havent been there for a while on my car, but are there copper washer gaskets used there? If not just apply a little bit of this stuff to the threads.
Also check your vent on your differential housing and make sure it isnt plugged with rust or dirt causing pressure to build up forcing your oil out.
P.S. when was your oil changed last in your differential?

[selwyngent]

Thanks. Will probably use some RTV sealant. Don't know when the gear oil was last changed, but it's a power directed differential so I'm not sure what to use in that.

[Don Henschel]

By power directed you probabably mean limited slip? If so you need a friction modifier additive. You have 2 choices, buy the oil with the additive in it already. Just read the label and it will tell you if it is intended for a limited slip or posi. The other choice is go to your nearest Ford dealership and buy the additive and just add it to your prefered brand of oil (make sure the oil doesnt have it in already). I believe the manual mentions 90W oil but you can use 75W90 or 85W90. If you are not sure what kind of diff you have, the oil with the additive will work in both. If you have both wheels off the ground with the transmission in park, turn one wheel forward and if the other wheel turns forward, thats a limited slip differential.