Lubricating Caliper sliders

[Grrrmachine]

Rebuilt a binding rear brake caliper, but couldn't see any particular problem with the piston, bore or seals. So I'm thinking it was the sliders binding in the rubbers.

I'm getting all sorts of mixed messages about what the pins should be lubricated with, so all comments are appreciated.

[Brianmoooore]

Mine get silicon grease.
Before I took my E39 for it's MOT last year, the front left caliper had been off and had the pins freshly lubricated. Time constraints dictated that the front right wasn't done, and the brake test results showed a marked difference between the two fronts, that we could only attribute to the freshly serviced caliper, even though the right hand one was found to be far from seized when stripped afterwards.

[capnmchl]

It's stuff like copper grease and normal multi purpose grease that swells up/disintegrates the rubber bushes.

I've managed to build up a big pile of little grease sachets that come with refurbished calipers over time. I've never actually looked into what they are (except the man from ATE coming round one day trying to market a big tub of the same shit but I wasn't really paying attention), but I expect it's silicon grease like Brian said.

[DanThe]

Copper grease is fine on brake rubbers

[Grrrmachine]

I've ordered a little tube of ATE Plastilube to deal with it. Reading far too many horror stories about using copperslip for this application.

[clipper]

My experience is that once the slide pins are worn to the extent that you can easily see / feel the steps and wear on the pins, it's a waste of time greasing and renewing rubber bellows.

I was constantly regreasing and cleaning mine with all types of grease until I finally gave up and admitted that the guide pins were shot. Admittedly my car has got over 340,000 kms.

[Grrrmachine]

I cleaned the old caked-on grease from the pins until they were shiny, but couldn't feel any steps or notches. So I lubed them up with this ATE grease and refitted them, and they're sliding back and forth smoothly now.

Unfortunately I need to drop my whole rear beam for another job, so we'll have to wait and see if it's fixed the issue.

[capnmchl]

There's 4 thing's that'll cause a floating caliper to bind:

Pads sticking in the carrier
Piston seized
Stuck slider pin
Damaged hose

If the piston moveed back and the pads come out the carrier without a fight, then it'll be the slider pins.