View Full Version : Front Calipers don't fit over rotors?
ChrisNicholls
09-12-2023, 04:59 PM
Just starting my kit and trying to install my front calipers over the rotors.
The rotors are fully 1" wide.
But the space between the brake pads is only 15/16".
What am I missing here?
Do I have mismatched parts?
Chris
189997189998
42Bfast
09-13-2023, 02:13 AM
I think those pistons are the screw-in type. There is a tool you can purchase to fit in the two slots/holes on the face of the pistons. (It is a small cube with a different stud pattern on each face.) You may even need to grind off a stud on the tool to get it to fit correctly.
You use the tool with a ratchet to turn the piston which widens the space.
(If the face of the pistons do not have slots or holes then they likely are not the screw-in type. If they are not, then you can use a C-clamp to compress the piston.)
Hope that helps.
gbranham
09-13-2023, 07:52 AM
I don't think the front calipers have screw-in pistons, or at least the kit-supplied PBR 2-piston calipers weren't with my recently-delivered MkIV Roadster kit. You likely just need to compress the piston a little bit more. I needed to on my build. The pads will contact the surface of the rotor, and it will be a tight fit when installed properly, but not so tight that you can't spin the rotor by hand once the caliper is installed.
Jeff Kleiner
09-13-2023, 07:57 AM
Front calipers do not spin in.
Jeff
If you're going to work on disc brakes at all, a tool like this will be very useful.
Astro 78618 Brake Caliper Wind Back Tool Set - 18 Piece https://a.co/d/hcEshBP
It has everything you need to compress or wind pistons for pretty much any car.
Alphamacaroon
09-13-2023, 11:39 AM
Doesn't the C in C-Clamp stand for "Caliper"? :p
Joking aside, if you don't want to invest in a special tool, one or more c-clamps will work in most situations. I have the same brakes and they were not the screw-in type. As others have mentioned, you just need a tool to push the pistons back into the caliper to widen the gap. You can even do it with your fingers if you do it before you put fluid in the lines.
Just be careful, if this is the first time you've worked on brakes, it probably wouldn't hurt to have second set of experienced eyes on them.
JohnK
09-13-2023, 01:33 PM
If you're going to work on disc brakes at all, a tool like this will be very useful.
Astro 78618 Brake Caliper Wind Back Tool Set - 18 Piece https://a.co/d/hcEshBP
It has everything you need to compress or wind pistons for pretty much any car.
Was doing some brake work on a friend's car recently, and we were able to rent that set from our local O'Reilly auto parts store. Good to have around if you do brakes often but if only needed once that's also an option.