Who "lubricates" the disc brake pistons?

[2tonevalk]

Was thinking while I was removing the disc brake cylinders, it seems my brake pads wear our faster these days.  They do wear even so it isnt one piston in a bind or anything.  The only thing I can think of that would be a deterent to doing it would be brake dust and contaminants getting in the lub.  HOwever I would not think it would be that much lub you would use.
I was thinking that perhaps they are keeping constant pressure (more so than usual) on the pad and wearing it out sooner.
Therefore, those of you who do your own maintenance, do you grease the pistons?  If so what do you use?  Spray lithium grease?  Moly paste?  Anti seize paste?
I am putting my tires back on this afternoon.  And if this is something that helps, I thought I might as well do it before putting the wheels back in place.
Thanks in advance for your input.

Ride safe
Robert

[hubcapsc]

The pistons probably don't move that much (there's just a narrow band of "clean space"
on the non-lubricated pin the pads move on)... the calipers ride on pins as well, and those pins
are covered with booties and lubricated with brake caliper pin lube.. I got a little packet of suitable
stuff at the auto parts store...

I rebuilt my calipers once, it's not hard and it brought my tired brakes back up to snuff...
if you're a "backyard mechanic" like me, though, I wouldn't recommend rebuilding them
this close to the blue/gray ride 

-Mike

[Ricky-D]

I would not lubricate the caliper piston.

There are two distinct ends to the piston.  The wet end and the dry end.

Lubricating the dry end will end up being a mess attracting all the crud there.

The wet end is already lubricated with the brake fluid and anything you may use could contaminate the fluid.

[Bagger John - #3785]

In addition:

Petroleum-based products will swell the piston seals and may render the brake caliper inoperative.

Don't allow any petroleum distillates to come in contact with your hydraulic brake system. This includes oil, gasoline, carb cleaner, etc. Use only isopropyl alcohol or brake cleaner as a cleaning agent.

If your pistons are binding: Remove the caliper from the bike, then squirt a little brake cleaner on the exposed areas of the pistons. Use a toothbrush to scrub away crud. This will prevent dirt from being dragged back into the caliper body and into the piston seals.

You are changing your brake fluid when it begins to show signs of discoloration...right?

[BonS]

I haven't bought Honda wheel cylinder seals recently but Yamaha wheel cylinder seals come with a red colored assembly lube that is very pasty and grease like. Always use it and never have problems. I have no idea what it is.

[franco6]

its probably silicone grease (synthetic) i always spray silicone on the pistons before pushing them back in for new pads .it stays dry,lubricates and feeds the seals. rebuilding the calipers is about 20 minutes work if you think it needs it do it! bleeding sometimes can be alittle tricky. the more you do it ,the easier! there i put my two cents in. good night!