Caliper rebuild lube

frankc · 08-02-2004, 11:22 AM

In the 911 Caliper Rebuild Tech Article (http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm) it recommends using a silcon assembly lube when putting things back together. The article recommends Sil-Glyde from NAPA. Our hosts sells a synthetic "Caliper Rebuild Grease" from Permatex. Is it OK to use the Permatex for the caliper bore and pistons? I am placing my order for the rebuild kits and want to know if I should add the Permtex to my order. If not, I'm sure I can find a NAPA around.

thanks.

Early_S_Man · 08-02-2004, 12:07 PM

Frank,

The preferred lube is Dow Corning 4, 111, or 112 ...

If you can't find it locally, do a Google search and order it online. It is worth the trouble to get it!

I strongly advise against Sil-Glyde because a tube I bought at NAPA about 10 years ago has turned dark brownish purple ... not the translucent clear it was when new!

I have a 1-lb can of 40-year old military surplus Dow Corning 4 that is still clear as the day it was packaged!

Since I haven't used the Permatex ... I can't comment on its' stability, but the Dow Corning silicone greases are a known quantity, and the standard in the aircraft industry and in the military!

911pcars · 08-02-2004, 01:11 PM

Clean brake fluid also works. However, Dow 111/112 might be more slippery. Clean, oil-free hands are required.

Sherwood

KobaltBlau · 08-02-2004, 01:48 PM

I'm doing this today. I don't have the dow corning stuff but I do have a silicone o-ring lube that is rated 400F like 4 and 111. close enough, hopefully. Warren swayed me to use silicone instead of the permatex stuff which is what I would have used. I would feel better if I knew what the base was on the permatex.

vash · vash's Garage

i have a tube of the sylglide and while it is still clear and good looking. it got kinda thick, i ended up putting a thin coat of the stuff and then i wet everything down with clean brake fluid anyways. now i have the dow #4 i use for everything. i ended up with two tubes, probably a lifetimes worth. the dow stuff is the best, it has the consistency of....damn how do i say this? some other lube, of the personal nature? oil return tubes are easy with the stuff. wish i had the stuff when i install the new master cylinder. those two o-rings from the reservoir were a PITA!

cliff

juanbenae · juanbenae's Garage

brake fluid worked fine for my rebuild. no fuss, no muss, dint even cuss... that was g@y i know.

John Brandt · 08-03-2004, 07:05 AM

So do you just lube the O-ring or the whole Bore?

Dow list #4 as an electrical insulator, not Automotive app. is this the same stuff?

dow #4

would the 111 / 112 be better?

Early_S_Man · 08:36 AM

John,

#4 is the 'the original' silicone grease developed for use on US military aircraft electrical systems in the '40s.

For a while in the '70s, Dow was marketing a lube called 4X that was touted for everything ... electrical systems, rubber lubricant, brake system rebuild assembly lube, etc. It was the same consistency & appearance as the military surplus #4 I had in the 1-lb can ...

Yes, apply plenty of #4, #111, or #112 to the entire bore surface, working surface of the piston, and inside of the dust shield boot before assembly ... wipe off any excess that oozes out after assembly.

BTW ... #111 used to be called #11, so it has been around quite a while ...

#112 is probably the preferred product to use if you are buying new, but it might be excessive to have all three on hand when #4 works so well for everything. Some people who are worried about specs go for #112 because it is rated 50° higher!

John Brandt · 08-03-2004, 12:40 PM

Dope sheet

4,7,and 111 are basically the same stuff in different consistencies

This says on p-2 that it shoud not be used on silicon gaskets, and I thought that our brake o-rings were silicon??? what d'ya think?

Highly multipurpose stuff for sure, I found a supplier (MSC) for #4 and a local yokel for #111

KobaltBlau · 08-03-2004, 01:13 PM

I used parker o-ring lube (silicone based, 400F like 4 and 111) on frickin' everything like warren says to. I would have used 112 if I could get it easily, I'll order some. when I bled I got some intermittent globs of silicone coming out the bleeder with the fluid, but I don't think this is really a problem. Warren? globs?