[wcj]

what do you think the chance is that i'll need new pistons?

I doubt the piston is bad unless it's got deep scratches in them. Ron Ayers said the front seal kit for the Pre was backordered so I ordered the entire kit including pistons and plan on just replacing everything. If you need some front pistons, let me know, I have some from my '90.

[hardlydangerous]

great job

If you use brake cleaner to clean the parts be sure to wear eye protection... I can't stress this enough. I almost lost an eye a few years back and have permanent damage and vison issues because of a bit of spray back.

[mwysienski]

thanks wcj, ill keep that in mind if i see anything wrong with them. i ordered the set w/o the pistons from Ron Ayers cause its a $70 difference if ur doin both calipers, which u should be. i got a confirmation email, and theres no indication of backorder...so far.

well noted hd, thanks.

[steves]

PDF added to the first post.

[Bucks23]

Is this the correct kit?

http://www.bikebandit.com/search-products

And I would need 2...

[Black_peter]

that page won't link..
Ahh changes..

[mwysienski]

I finally got my back ordered rebuild kit (rip off, about an ounce of rubber) in the mail and got to work. i wouldnt have had any troubles without these intructions but its nice to get a little confidence boost before you jump into a project.

i just want to point something out. the pistons are held in pretty tight by the rubber gaskets that surround them. it's not nearly as easy as it looks to pull them out as in the picture. i had to grab the tiny top edge of the pistion with pliers and pull up while spinning the piston. simply putting the one end in and trying to pry it upward did squat.

if anybody follows my description there, you have to grab as little of the pistion as possible (1/8" max). you probably shouldnt even be doing that cause the outside of the piston (the surface that rubs with the gasket) should be as smooth as glass. however i couldnt figure any other way to do it. plus the piston doesnt go all the way down to the gasket anyway, but its dam close so be careful.

in regards to dificulty that i encountered with removing the pistions, i think the old gaskets were still in good shape. someone with truely rotted out gaskets would prob not have as much trouble.

also, i wouldnt rely too much on the compressed air method.

oh, i forgot. first thing you want to do it take the brake line off the caliper. dont take the cap off the brake fluid resevoir. the lack of air pressure at the top of the system will only let a tiny bit of fluid leak out the bottom of the hose, unless you have a bad seal somewhere up there. have you ever put your finger over the top of your straw and then poured your soda into your mouth by letting go of that finger (or onto the table to make the scrunched up straw wrapper expand)? same theory. i used two small water bottles from out of the trash to put the hoses into and then smooshed them in between the down tubes of the header.

when you take those calipers back to your work bench (or floor), thats where youre going to see fluid come out. so be prepared for that.

[steves]

also, i wouldnt rely too much on the compressed air method.

How so? That's worked well for me, even on 20 year old neglected GS parts.

[Black_peter]

i just want to point something out. the pistons are held in pretty tight by the rubber gaskets that surround them. it's not nearly as easy as it looks to pull them out as in the picture. i had to grab the tiny top edge of the pistion with pliers and pull up while spinning the piston. simply putting the one end in and trying to pry it upward did squat.

Not to be too terse but either you did it wrong or your pistons were a mess.
They should in fact come out that easy. I would never advise grabbing any part of outside of the piston with any tool..

[arsenic]

agreed, if you cover every hole that air comes out of and spray compressed air in there they pop right out.

[steves]

Maybe you mean, the first one came out, but then you couldn't get the second one out. I put the first piston to pop back in, lubing with with some brake fluid first, then use the old brake pads to "hold" it in place while I am pressuring to pop the second one.
On the front anyway... the rear is a little more difficult since it's opposed.

[mwysienski]

well i guess all eight of my pistons had something wrong with them then.

[Black_peter]

well i guess all eight of my pistons had something wrong with them then.

Well I guess so...

[joeyz34]

started rebuilding my front calipers while waiting for some other parts to come in too...

thought i'd post a pic or two...





not quite done yet... ran out of acetone, and didn't get more till today...

[ThAzKat]

Yet another great writeup bro!!!

Might I add that if you are cautious you can use compressed air to remove the pistons also. If you don't have a compressor you can use the pressure of the master cylinder to push the pistons most of the way out.