Parts for Rebuilding a Brake Caliper

[mokosai]

This is the fiche for a caliper for a 1980 GS250T.

I've never taken a caliper apart before. My Clymer manual advises throwing out and replacing all rubber pieces whenever you have a caliper apart. After 30 years, I agree!

So, which part are rubber and should be replaced?

2 is a "piston seal"
3 and 11 are "boots"

So, I imagine, those three?

[Agemax]

yes but if the piston is in bad shape then you can buy it as a set with parts 2 and 3 included.(item 1)

[Dogma]

Yes, that. Also, 11 may or may not be damaged by some leaking fluid, and 14 is nice to have in good condition. Some visual inspection is in order before ordering parts. You can't assume you won't need a piston; you can't assume you will.

[spyug]

Dogma is correct IMHO. Best to take it apart to see what you are up against. In my experience, there is about a 70% chance you will need to replace the piston as often they are damaged by rust buildup. If the piston's chroming is cracked or pitted( on the area inside the caliper bore) you will need to replace as rusting can and will freeze the piston. Have a look at this one for an example of what you might find:



While that one was not frozen there was a buildup of rust starting in the caliper and it could over time have started to eat at the piston.

That caliper and piston did cleanup well and while the seal was still good, it got replaced.

It is best not to mess around with your brakes so when in doubt, "change it out".

Good luck with it.

cheers,
spyug