gdwisni

First thing first, my 04 Z has a Wilwood 13in front and rear bbk from Evolution Auto /brakezone. Originally the front caliper brackets were too short causing the caliper to rub the rotor hat and the rotor itself to rub the inside caliper body. I had sherwin(brakezone) send me out a new set of brackets that held the caliper further away from the center of the rotor. Every thing seemed to fit since the rubbing was gone.

Fast forward to now.

Recently I have noticed a strong vibration under partial braking at different speeds. I took off the wheel to see what was going on and found that the remade brackets held the caliper too far off the center of the rotor and that the entire pad was not making contact from the rotor leaving the top of the pad unworn. Could this lip of brake pad material be causing the vibrations and can I get new brakets from someone other than brakezone since I believe the maker (Sherwin) has take a leave of absence?

Any help or advice is much appreciated.

Greg

C Ray Z

iTrader: (2)

I had to shim the caliper to center the gaps on both sides of the rotor. Did you do this at your first installation? I have had my set for two years and two sets of pads. I did however just have the shudder in the front caused by a warpped rotor due to the heat. I too have turned my black front calipers purple from the heat. so it might be this problem your are having. I have had very even wear on my pads. More wear on the rears then fronts but even.

My system is by 350zbrakes.com. I have 13.6" rotors with 6 pot front and 13.6" rotors in the rear with 4pot calipers.
Just my experience to date.

J Ritt

iTrader: (4)

C Ray Z,
A slight bit of pad overhang is sometimes acceptable, especially if there are tight packaging issues for a particular application. Usually it would not be over 1 or 2 mm though, and what you show seems to be quite excessive. It appears that there is still a portion of unused rotor surface on the ID (inside diameter) of the rotor face, but there may be other fitment issues on the inside of the caliper and/or between the hat and the caliper that prevent the caliper from being positioned a bit closer to the hat. On some race car applications, the caliper is actually positioned so the pads overhang the OD (outside diameter) of the rotor slightly. This is done so when the rotor grows in diameter under high heat, the outer edge of the pad is utilized. Any lip that forms on the pad is broken off as the rotor grows, but again, this is only on very high speed, purpose built race systems.

In most cases, the caliper should end up centered over the rotor. StopTech typically mounts the caliper bracket on the same side of the caliper mounting ears that the factory caliper mounts against. This is a dimensionally controlled surface from the factory, and means that we can design the bracket so no shims are necessary to center the caliper over the rotor (true bolt-on). We have moved the caliper as much as 1mm off center to accommodate some special clearance issues, but any more than that and we would run into other issues. If the caliper is too far off the rotor center line, the pad may have trouble fitting into the narrow side, and the pistons may extend too far on the wide side when the pads are worn down close to the backing plates.

In regards to your vibration; if the hat and rotor assembly is a true floating system (can't tell from picture), let’s presume it is not “warping.” The pad overhang may not directly contribute to any vibration, however squealing could be an issue as the outer surface of the rotor can remain in contact with the lip of pad material. Usually when the pistons retract and relieve pressure from the pads, the pads break contact and pull away from the rotor. If the caliper being off centerline of the rotor is enough to cause a pad to not release and drag, that could overheat the pad and/or rotor and cause uneven pad deposits on at least that one side of the rotor. If the hat and rotor assembly is NOT floating, then there could possibly be some warping if the brakes have been used very aggressively. More than likely though, the vibration is an uneven pad deposit caused by continual contact and overheating of the pad material as it drags on the rotor face.

The solution is the tough part. For a quick fix of the vibration, you may be able to put some very aggressive friction in there and try to remove the pad deposits. See this link for more details on that process:
http://www.stoptech.com/tech_info/wp_padremoval.shtml
If that doesn't work, you may have to have your rotors resurfaced to remove the deposits.

I think you're going to have to get your Wilwood supplier to remedy the issue in the long-run however. Unfortunately, we don't do any type of 'one-off' brackets, etc., so I can't offer you anything to fix the problem other than analysis and recommendation. All of our kits are designed uniquely for each application, so none of our brackets fit multiple vehicles.

Unless the caliper is positioned properly in the long-term, you're going to potentially keep running into tapered pad wear issues, pad dragging, uneven pad deposits, cocked pistons, etc.

Let me know if you have any other questions, etc. Good luck.
Jeff

C Ray Z

iTrader: (2)

I assue the pad sitting in the caliper was not moved to this spot. There should be a screw that goes across the top of the caliper. It hold the pads in place as well as supports the caliper. This is missing. I have this screw on my setup

gdwisni

Actually I did move the pad out to photograph the lip of the pad and that is why the pad retaining bolt is not in place. I might order new pads, pop them in and see if the vibration is gone. This would mean that the un-used pad lip is what is causing the vibration. Thanks for you help so far everyone.

Greg

C Ray Z

iTrader: (2)

You should not see that non contact area. I do not have that. It almost looks as though the caliper is sitting .2" higher than it should. My rotors just clear the caliper in the groove by .1". You might check you clearance.

J Ritt

iTrader: (4)

I was assuming that the pad had been pulled out by hand for the photo. That said, if you look closely at the pad, you can see a dark arc on it that looks like a ridge from contact with the rotor edge. That's where I was assuming the overhang was beginning...which is still quite a large distance.

gdwisni

Correct J Ritt ... originally the brackets I was sent were just a little short and the edge of the rotor rubbed the inside of the caliper slightly and the rotor hat rubbed sliightly as well. The wear you see in the pics is from the second set of brackets which I feel moved the caliper too far away from the center of the rotor. What I need is a set of brackets inbetween the original and the current ones which might be a problem because I believe the designer of the brackets is dealing with personally issues and is away from the shop(brakezone). If I can't get what I need from them maybe I can find someone to make me one off brackets. Thanks for everyones help so far.


Greg

C Ray Z

iTrader: (2)

I found that mine also got some rub but by wedging a screw drive on both sides of the top of the rotor and caliper I could hold the caliper to one side and then torque down the caliper and would have the .1" celarance. You might try this with the original brackets.