Brake caliper assembly lubricant?

[FireFox31]

What lubricant can I use on the internals of a brake caliper to reassemble the piston? I disassembled and cleaned the calipers, had them chemically dipped and powder coated, so they are completely dry and free of grease.

The lubricant will be in contact with brake fluid, thus eventually circulating in the system, so should be compatible with brake fluid. The only one I've found which says it's for the piston and will safely merge with brake fluid is this German ATE brake assembly paste. It seems to be only available in Europe and I can only find one supplier carrying 5 gram containers.

I checked the lubricants from ATE (Plastilube), Permatex, AGS (Sil-Glyde), and CRC. I'm not convinced that these are for caliper internals and safe to brake down in brake fluid. They all seem to be for pins and pad mounting surfaces.

Other sources online say to use brake fluid for caliper reassembly with one caveat. Brake fluid absorbs moisture from the air so a caliper which uses it must immediately be installed. In case you wanted your assembled caliper to sit on a shelf for a while, something like silicon would be needed to avoid that moisture absorption.

What do you all think?

[Cees Klumper]

https://www.amazon.com/GENUINE-Corrosio ... 5110&psc=1

[WhatAmIDoing]

You could use DOT 5 silicone based brake fluid. I don't think that miniscule amount will hurt anything after bleeding out the caliper.
Edit: should probably make sure the rubbers are compatible with the silicone first.

Fun fact: I filled 2 old calipers with WD40 and capped off the inlets before storing them in a damp place for a year or 2. Didn't seem to hurt anything. They went into service just fine.

Would be interesting to know what reputable brake rebuilder use to coat the inside to prevent rusting while sitting on the shelf.

[454cid]

You could use DOT 5 silicone based brake fluid. I don't think that miniscule amount will hurt anything after bleeding out the caliper.
Edit: should probably make sure the rubbers are compatible with the silicone first.

Fun fact: I filled 2 old calipers with WD40 and capped off the inlets before storing them in a damp place for a year or 2. Didn't seem to hurt anything. They went into service just fine.

Would be interesting to know what reputable brake rebuilder use to coat the inside to prevent rusting while sitting on the shelf.

I don't think Dot5 is compatible with Dot3/4. I've heard of guys using something like WD40 and not having issues. I'd assume the amount is small enough that they're able to "get away with it", rather than it being a good practice.

I'd use DOT4 and not worry about it. I have never stored a caliper off the car, Though.

I'd also guess a reputable rebuilder moves their stock fast enough, to no worry about it.

If the caliper will be stored, one could simply keep the piston and seals out, and spray it off with brake cleaner and assemble it before installation.

[abscate]

There used to be a brake wheel cylinder assembly paste that was compatible with brake fluid but I haven’t seen it in years.

For storage just moisten with fresh brake fluid , bag it, store it in a dry place.

[scot850]

This is one of those oxy-moron events. The one assembly lube I found is Centric brand...................!

https://www.autobrakecenter.com/-lube-502.10000

Neil.

[FireFox31]

This is one of those oxy-moron events. The one assembly lube I found is Centric brand...................!

The reason I need this caliper is because one of mine failed after 15 months of light use. Yup, Centric brand. Nope, not buying their lubricant.

If the caliper will be stored, one could simply keep the piston and seals out, and spray it off with brake cleaner and assemble it before installation.

That's what I'm planning to do. I need this caliper temporarily until I can get a replacement for the failed one. I'm not ready to put the powder coated ones in to service full time yet. And a note: The powder coating company told me to clean them with anything buy brake cleaner. This is specific to powder coated calipers so your advice works for everyone else.

I'm going to ask Boxer2Valve.com if they can get me the German ATE assembly paste in the 180g tube size. Will probably buy two since it's hard to get.

[scot850]

You could vacuum seal them in bags with desiccant packs inside with the calipers. I do that with lots of car parts, especially electronics that are small enough to go into the bag sealer unit we have.

Neil.

[abscate]

If you buy more 1998, 1999, and 2000 cars you will naturally rotate your own stock…