Front Passenger Brake grinding, this might be why.

Chythar

Recently finished repairing my rear
20+ Year Stangneter :roc</strong><span class=
Aug 26, 2004
2,373
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Foothill Ranch, CA
A bit of background. This issue is on my Cobra clone. The passenger front brake was rubbing on one spot of the brake rotor as the wheel went around, making a nice rubbing noise. I popped off the wheel to look for anything odd, but I couldn't see anything. I HAD to leave to get the vehicle inspection done, so I went. Since I couldn't see anything obviously wrong, I figured maybe I had a warped rotor. The rotors and pads were brand new, but it's possible. The car acted like it had a warped rotor; the steering wheel shook when I applied the brakes. However, the shaking got lighter & lighter every time I used the brakes, until it stopped. The steering wheel doesn't shake anymore when using the brakes.

I was also getting a nice grinding noise from the same corner when I would back up, like the brake pads were catching on the rotor or something. Only when backing up. Hissin suggested the brake slide pin was sticking, so I popped off the wheel today to grease it all up. I found something weird, not exactly sure if it's a serious problem or not. Using brake anti-squeal grease, I greased up the ends of the pads (that lock into the caliper bracket) and the slide pin that locks the Cobra caliper into place. I drove the clone back & forth in my driveway a bit and I didn't hear any rubbing or grinding at all. Perhaps the caliper really was sticking.

I took some photos of the caliper bracket that have me a bit worried. I'm not sure if this is a bad bracket or if it's within factory tolerances. Take a look below.

This photo is a composite, showing the clearance between the bottom part of the bracket and both sides of the rotor. In person, the distance looks to be about the same.

caliper_bottom.webp



This next one is what worries me. There is barely any clearance between the rotor and the bracket on the inside. The outside has more room than it needs. The bracket is fully bolted in. The rotor is not touching the bracket now, but the outer edge might have been at one time. The faint bright line between the rotor and the bracket is actually the ground showing through - that's how close it is.

caliper_top.webp



This doesn't seem right. I at first thought the caliper bracket was bent. but the spacing between the rotor and bracket is even from top to bottom. After greasing up the caliper, the brakes aren't making any noise anymore.

Is this something to worry about? I think so, but I would like some opinions. Is is possible I have a defective bracket? I haven't compared the left and right caliper brackets to see if one is cut differently or not.

Ideas?
 
A bit of background. This issue is on my Cobra clone. The passenger front brake was rubbing on one spot of the brake rotor as the wheel went around, making a nice rubbing noise. I popped off the wheel to look for anything odd, but I couldn't see anything. I HAD to leave to get the vehicle inspection done, so I went. Since I couldn't see anything obviously wrong, I figured maybe I had a warped rotor. The rotors and pads were brand new, but it's possible. The car acted like it had a warped rotor; the steering wheel shook when I applied the brakes. However, the shaking got lighter & lighter every time I used the brakes, until it stopped. The steering wheel doesn't shake anymore when using the brakes.

I was also getting a nice grinding noise from the same corner when I would back up, like the brake pads were catching on the rotor or something. Only when backing up. Hissin suggested the brake slide pin was sticking, so I popped off the wheel today to grease it all up. I found something weird, not exactly sure if it's a serious problem or not. Using brake anti-squeal grease, I greased up the ends of the pads (that lock into the caliper bracket) and the slide pin that locks the Cobra caliper into place. I drove the clone back & forth in my driveway a bit and I didn't hear any rubbing or grinding at all. Perhaps the caliper really was sticking.

I took some photos of the caliper bracket that have me a bit worried. I'm not sure if this is a bad bracket or if it's within factory tolerances. Take a look below.

This photo is a composite, showing the clearance between the bottom part of the bracket and both sides of the rotor. In person, the distance looks to be about the same.

caliper_bottom.webp



This next one is what worries me. There is barely any clearance between the rotor and the bracket on the inside. The outside has more room than it needs. The bracket is fully bolted in. The rotor is not touching the bracket now, but the outer edge might have been at one time. The faint bright line between the rotor and the bracket is actually the ground showing through - that's how close it is.

caliper_top.webp



This doesn't seem right. I at first thought the caliper bracket was bent. but the spacing between the rotor and bracket is even from top to bottom. After greasing up the caliper, the brakes aren't making any noise anymore.

Is this something to worry about? I think so, but I would like some opinions. Is is possible I have a defective bracket? I haven't compared the left and right caliper brackets to see if one is cut differently or not.

Ideas?

How about taking the picture again showing the position of the brake pads relative to the rotor and caliper. Better picture focus would also help. You are right it just doesn't look right.
 
I dont have experience with snake brakes but that looks scary.

What happens to the clearance if you bolt a couple of lugs nuts to the studs? Wonder if that makes it even worse or makes noise?
 
I dont have experience with snake brakes but that looks scary.

What happens to the clearance if you bolt a couple of lugs nuts to the studs? Wonder if that makes it even worse or makes noise?

I was holding the rotor in with my hand for those photos, the rotor just clears. It might very well scrape if I put lug nuts on and torqued them to spec.
 
Space the bracket with some grade 8 washers.... Just make sure that they are the same thickness (measure)... I recall something about spacers when I put on my cobras...

Unfortunately, the spacing is the other way around - the bracket is too far out from the spindle. I'd have to remove material from the caliper bracket. Which is my plan, actually. It looks like there is too much material at the mounting point, where the bracket is attached to the spindle. This pushes the bracket out too far on one side. The plan is to remove the extra material so the bracket is spaced properly.

I'll post an update later.
 
Your wheel bearing probably went bad. When the bearings go bad, the wheel will walk in and out when it turns, and it can obviously displace the wheel in any direction. To test for this, take the brake caliper and bracket off completely. Bolt a straight rotor tight to the bearing plate with two nuts. Then use a dial indicator on the edge of the rotor. Turn the wheel and see how much play you have on dial indicator. I didn't find out how bad my wheel bearings were until I swapped out to my Aerospace brakes. The tollerances on the Aerospace brakes were so close, that they didn't allow for as much play in the bearing, and the rotor would scrape on the brackets when it turned.

Kurt
 
Your wheel bearing probably went bad. When the bearings go bad, the wheel will walk in and out when it turns, and it can obviously displace the wheel in any direction. To test for this, take the brake caliper and bracket off completely. Bolt a straight rotor tight to the bearing plate with two nuts. Then use a dial indicator on the edge of the rotor. Turn the wheel and see how much play you have on dial indicator. I didn't find out how bad my wheel bearings were until I swapped out to my Aerospace brakes. The tollerances on the Aerospace brakes were so close, that they didn't allow for as much play in the bearing, and the rotor would scrape on the brackets when it turned.

Kurt

Having a worn bearing makes a LOT of sense. It would explain the grinding when I backed up - the bearing shifted slightly so the rotor contacted the bracket. However in my case, the bracket is also bent somewhat. I still had my old stock brakes and a rusty rotor lying around - so I bolted them on and there is good clearance all around. So basically, I need a new caliper bracket. I ground down the bracket for some more clearance for now, until I can afford another bracket. Money is really tight right now. :(

Now, how did I get a bent bracket? Well, the donor wrecked Cobra was hit pretty hard on this same wheel in the accident that totaled it. Maybe the caliper bracket took a hit somehow. :shrug:
 
He looks like one of my cats. I got a 22lb black one, and a 15lb tabby/mancoon. The tabby is crawling all over me right now. They are both really awesome cats, but they cut into my internet time.

Kurt