Folks, I'm changing my rear pads. Got everything removed and the pads out.

The pistons are *filthy*, and I'm not sure they will accept the paste.

Should I spray brake cleaner in there to clean it up?

Or will brake cleaner destroy whatever lubrication for the pistons there may be?

 

definitely spray them down with cleaner, use and old pad and squeeze the brakes till the pistons are pretty far out so you get the all nice an clean, then use the old pad to push them back into the caliper for replacement.

 

Hose it down !! Maybe not a bad idea to extend the pistons a bit and clean with a q-tip or pipe cleaners or >>>????

 

Oh hell yes, spray the **** out of them. As said above, try to extend them out and get the sides. Those things pick up road dirt and stop retracting after a while. That's what happened to mine. Clean 'em good.

 

String works well to scrub the pistons clean.

 

Works, but evaporates fast; I put some WD40 on a rag, wipe them down with that. With the pads out, I put something in there to block the pistons from coming out too far and squeeze the brake till I get clean bare metal behind the grime; that way I know I got it all. Just kind of loop the rag around the piston, work it back and forth, and usually cleans it right off.

 

Don't let that crap set on any painted or clear coated surface, it will ruin it. Trashed the clear coat on my front wheel by letting brake cleaner puddle on the rim.

 

Formula 409 does well too. Let it soak for a few minutes, brush it around a little bit, rinse well, not quite as harsh. I like to wash my bike really well a day or so before working on it, less grime to deal with. I call that cleaning a "Wash and blow" (Leaf blower, that is!) without a bunch of detailing. Lots of crap washes right out of the caliper at that time, too.

 

Simple Green is probably a better alternative than brake cleaner and wont harm anything.

 

Can lift the paint right off a new John Deere tractor...