front caliper problem.....leaking

[bell]

over the winter my front right caliper sarted leaking at the outer piston seal. i removed it and rebuilt it with new seals.....
after about 1000 miles it does it again.........
again i pull the caliper and replace and reclean everything......
tonite i'm pulling my front wheels to stick on new tires and it's leaking again.
when it leaks it's coating the rotor with fluid causing a heavy pull to the left.
was planning on driving the allegheneys this weekend but this may kill that plan.
thanks

[Early_S_Man]

bell,

Were either of the pistons in the offending caliper pitted or scored over the 'active' 2/3 of the cylindrical surface that the rectangular cross-section seal has to slide over in normal operation? If so, that is the problem. Light rust can be removed sometimes with ultrafine Scotchbrite ... but pitting on the cylindrical working surface ruins a piston, and makes it worthy as a paperweight!

Did you use silicone grease on the piston and seals when rebuilding the caliper?

[bell]

i used silicone grease to install the pistons, both the walls of the piston/cylinder have zero rust and no pitting.......this is why i'm baffled.

[toolman]

You could have nicked a seal or have a defective seal.

[Parkin Hunter]

Re: Did you use silicone grease on the piston and seals when rebuilding the caliper?

I am in the process of rebuilding the calipers on my 80 SC and have received conflicting advice about silicon grease. Ordered the lube from Pelican but have also been advised by Pelican that should use brake fluid only.

What is the preferred method?

Thanks.

[sundaypunch]

I use Sil-Glyde on the seals. I realize that some people prefer other products but Sil-Glyde is made for this purpose and is used by most of the mechanics I know.

As for your problem, if the piston doesn't have pitting it's possible that the seal was sheared when installing the piston.