rotor replacement

[micbrody]

I am replacing my rotors.

I received "Centric Parts 120.04000 Premium Brake Rotor with E-Coating"

The front rotors easily were replaced.

The backs have been a problem.

1) rotor did not come off when I removed the two rotor screw pins. I had to rotate and give repeated gentle rubber mallet tapping to free the old rotors.

2) I placed new rotors on; tightened the rotor screw pins. But the rotor would not seat exactly flush to hub. I figured maybe I just applied incorrectly. I removed pin screws and carefully placed again. No matter what I would do there would still be a tiny amount of wobble.

I then theorized that since old rotors were super tight; maybe when I tighten the wheels to rotor, everything will get flush.

I tried it with car up on jacks; could not get it super tight; then removed wheel, and sure enough, the rotor must have seated more because one of the rotor pins was loose.

Question for the forum:

How to proceed?
My plan was to reattach wheels. Lower car, and then do final tightening of lug nuts. My theory is that at full torque, rotor will seat fully; however, I would assume I have to again remove wheel to tighten the rotor pin screws.

Am I missing something in this procedure????

[spider2081]

Did you try cleaning the axle hubs with a wire brush or Scotch bright pad and die grinder??

[micbrody]

No; am I suppose to?

[DieselSpider]

No; am I suppose to?

Yep. You need to clean any rust off the hubs that might prevent the new rotors from lying flat against the axle hubs or you can have pulsating brakes and rough stops. I remove the spacers too and clean those up while I am at it.

You want metal to metal contact not metal to rust.

Do not grind them but do clean them.

[micbrody]

DieselSpider,

Thanks for advice. You were correct. However, what I intuitively thought needed the most cleaning on hub was actually not the part that was causing problems:

The following is mainly for future members who have this problem:
I cleaned center of hub that has grease seal, that sticks through mounting hole of rotor, with wire brush and PB blaster. It still was wobbly and tight. I then just tested the rotor backwards to see if it would lay flush; and it did. This indicated that the problem was actually the outer rim of hub that "squeezes" into inside of rotor. The inside of rotor (not a brake surface; but where the hub goes into), if one looks carefully actually has a tiny 'ledge' that makes functional inner diameter smaller (really tiny).
In order to have this ledge pass the edge of hub, I really had to clean the outside edge of hub very hard; and took a hand file to remove any oxidation the brush would not remove. When I then mounted the rotor, I first applied the rotor pin screws hand tight; then it required light rubber mallet taps to seat the rotor. I finished tightening the rotor pin screws to spec. But at the end, it sat totally flush.


As a "bonus" to my brake work, I discovered my parking brake did not work on back right wheel (I had rebuilt left with emergency brake, but was underwhelmed by function of parking/emergency brake; never got around to rebuilding right rear brake). The PO that rebuilt left rear piston totally had things in wrong places; he/she must have tried working on the right. The reason the parking brake did not work on that wheel was because it lacked the "levering wedge" that mechanically pushes on piston via parking brake cable. Luckily, the hydraulic part works fine.

Does anyone have an extra "wedge"? or tell me what it is really called; and who sells them?

[klweimer]

You may have a tough time finding just the wedge thingie (not its real name ). I'd probably either go with new from AR or buy a used one on ebay and rebuild. The one you have now may be missing other parts. I bought a rebuilt one by Cardone and it was complete crap. A quick look on ebay turned up these. http://www.ebay.com/itm/FIAT-124-SPIDER ... DZ&vxp=mtr
Kirk

[micbrody]

Thanks for eBay link. I will send question to see if they can take rubber cover off and photograph .

Just found good diagram
The part I need is called a "pawl"