Install Question on Rear Disc Brakes

[Warsaw Jim]

I hate to ask multiple questions under one post but they are all related. Answers to any or all would be appreciated.

My 3.1 kit (separate Wilwood master cylinders for front and rear) has the single piston rear disc brakes. I'm upgrading the kit pads with Carbotech XP 8 pads. I couldn't get the piston to retract. As a last step I looked at my Mustang repair manual. It states "the piston must be screwed back into the caliper bore, using Piston Turning Tool T75P-2588-B or equivalent, to provide installation clearance."

First question: I don't have the tool. Is there a procedure for the average shop tools person to use to allow the piston to be relaxed?

Second question: Seems like I read special stips that could be put between the pads and the rotor to measure the pad pressure. Anyone have a comment on this?

Third question: I had to replace the passenger rear axle recently. I bought a 3rd party axle that came without the round shim piece that goes between the axle and the rotor. The installer got the shim off the old axle but did not have a press to put it back on the new axle. Now it slides on and off. The wheel holds it in place. The shim is needed to compensate for the 1/8" difference between the size of the axle and the rotor. Any comments?

[Michael Everson]

1. Any parts store will have this simple tool. I have also been able to screw it in with needle nose pliers. Just put the tips of the pliers in the notches on the face of the piston and rotate clockwise n

2. Never heard of it

3. Shouldn't be a problem. Some people even use an O-ring for this purpose.
Mike

[rich grsc]

Try some red Loc-tite.

[Warsaw Jim]

$14 for the special tool. Everything can be so simple when you have the right tool and some idea of what you are doing.

The rotors do not sit flat on the axle when the caliper is mounted. It can be pushed back easily with the wheel off. When the wheel is on the rotor will be pushed squarely against the axle or so it seems to me. Is this any sign of a misalignment or simply the way it is? In the old days there were little clips that slipped over the wheel studs to hold the brake drum tight. Just wondering?

[ClemsonS197]

Originally Posted by Warsaw Jim

The rotors do not sit flat on the axle when the caliper is mounted. It can be pushed back easily with the wheel off. When the wheel is on the rotor will be pushed squarely against the axle or so it seems to me. Is this any sign of a misalignment or simply the way it is? In the old days there were little clips that slipped over the wheel studs to hold the brake drum tight. Just wondering?

Are you talking about this?



They are just a cheap clip used to hold floating rotors on during manufacturing. The rotors used on these cars are "floating" and when you light tighten down the wheels, they will align the rotors. So take a lug nut and tighten it down without the wheel. It will make the rotor flush where it should be. Like this:

[Steve Powell]

Buy the tool at Harbor Freight. It's cheap but works OK and makes the job of retracting the pucks a bunch easier. If you need a new spacer to make your rotors hub-centric Mike Forte sells them. They are aluminum and are a light press fit on the axle.

[Warsaw Jim]

The cheap clip was what I was talking about. Doesn't sound like I need it. I'd already did the lug nut deal. The $14 tool was from a local parts house and worked like a champ to get the piston positioned so the pads simply slid into place.

Now while I'm kinda torn down I'm going to go through the Wilwood balance bar adjustment procedure. I've printed off a bunch of reading material. With the XP8 pads on the rear and the XP10 pads on the front with the balance bar adjustments fine tuned I'm hoping to get some really good brakes. Wish me luck and if you have any good suggestions let me know... Jim