flood

What should I use to spread the pistons in the caliper? Do I need a special tool for the 4 piston calipers?

Also I will be turning the rotors on all 4. Any tricks / tips and pitfalls will help out. Thanks :cool:

Larry B.

The tool sold by most corvette parts houses makes the job easy. It is worth the price (cheap). Do NOT turn the rear rotors. It will result in run out and the pumping of air into the system. There was just a topic about this.

Tyler Townsley

I use snap ring pliers and push on the pads, once spread I put in a socket to hold them apart until slipped over the rotor.

Tyler

RJR99SS

i've always just put a flathead screwdriver in between the pad and the caliper and pried the piston back into the bore. Every proffessional mechanic i know just does it like this. Course it has sort of a "grease monkey" feel to it....

dath

I wouldn't do it this way. I've done it that way and I'm pretty sure I screwed up one good caliper doing it this way as you can fowl the piston sideways and screw up the lip seal doing this... Best bet I have is to either use the tool sold by the Vette stores (caliper clipper I think they call them, I've got one, but never used it), or better yet, remove the pesky springs that seem to have no good use other than aiding air intake into your braking system... That's the solution I'm using anyhow...

Oh yeah, as for having the rotors turned, if you do it, see if there's a shop that can do it on the car. If not, make sure you measure the runout when they are on the car and shim them to get them within .003" total runout if possible.

wcsinx

How strong are those springs really? I've always just grabbed the calipers with my hands and squeezed the pistons down with my thumbs. It's not as hard as it sounds, but then again I've never tried this on spring loaded pistons.

stingry

My buddy and I made up small blocks of wood. Costs about a nickle a piece as opposed to the price they charge in catalogs for a piece of bent metal. Just measure the thickness of your rotor then cut a piece of 2" X 2" to that length. You will need two to do a caliper. WIth your hand pull back on the pads and slide in the blocks. If you have a lot of trouble use smaller blocks initially then build up to bigger blocks. Yes the springs can catch but if you wiggle the pads a little they will free. Then just slip the caliper over the rotor and the blocks of wood get pushed out of the way by the rotor. Make sure your master cylinder is open when you do this. Put rags under and around it as you will be pushing the fluid around and may cause some splash. If you don't crack the brake system you will experience "Hydraulic Lock" ie you will be trying to compress the psitons and there is no where for the fluid and air to go hence it is very difficult if not impossible to push the psitons in with the system closed.

Keep sharp objects away from those seals. They look flimsy enough!

Good luck.

Pete
STINGRY
:steering:


[Modified by stingry, 7:11 PM 8/26/2003]


[Modified by stingry, 7:11 PM 8/26/2003]

dath

The springs aren't that strong. You can easily push the pistons back into the bores when the calipers are off of the car. Never tried pushing them by hand with them on the car since there are four of the damned things... Every time you push one, the others want to move out even more than ones without springs... I say take out the springs, seriously, it is rumored to help with the air injestion problem...

mrvette

If you are talking a new caliper with no fluids, and old decent corvette mechanic I know, just slips the pads in place, pin and all, pushes them back with his two hands/fingers, and slips the damn thing home, all in an accomplished movement....like its freaking nothing....course it helps to be a pro....duh.....

I removed the springs straight away on my first rebuild about 7+years ago when the original lip seal pistons were in there, and it ran fine for about 5 years like that, but they slowly began to leak I do wonder if the DOT5 fluid does gradually attack the rubber used in brake systems....I dunno....
but anyway, it's an O ring system now, and so the pads were just changed, and the pistons pried back with a screwdriver, and pad inserted, first one side then the other....no sweat...messy floor under the m/cyl...but that's life....

GENE

flood

So there are places that can actually turn the rear rotors while they are on the car? This sounds crazy to me :crazy:

I am concerned about this as I have heard of problems with the rear rotor runout. I will measure the runout.

It seems impossible to turn the rear rotors without causing problems with air. What a PITA ! Cause my rotors are really glazed and squeal like crazy. I have heard of using emory cloth to get the glazing off. Maybe I will just turn the fronts and try this on the rear. :confused: