Rear brake grind

[Richard H.]

Hi,

I am working on a 1970 coupe. I have a problem with the rear wheel. The outside of the caliber is grinding on the rotor. The trailing arm has been rebuilt and the caliber and rotor were new. A mechanic tried to grind the inside of the caliber were it attaches to the trailing arm to gain more clearence on the outside. That did not work. I am planning to order a new caliber and a new rotor, I am hoping it is not the trailing arm. Before I order the new parts I thought I would run it by the membership.

Thanks,
Rich Harris

[Gary R.]

Re: Rear brake grind

Richard,
Sounds like the caliper bracket is bent,causing the caliper to be cocked on the mounting. Could be bent ear on the caliper but usually it's the bracket.
I check the brackets when I have them apart to see if they're bent, using a spindle press will bend them a lot of times.
With the rotor and caliper mounted I spot down and look at the caliper seam, it should be on center of the rotor, if it's bent you will see it taper off.
If the bracket is bent then you have to start all over, DO NOT attempt to reuse bearings once they're pressed off. Sometimes they can be used but most times they're going to get wrecked removing them. It's just not worth it not to use new bearings. I would be calling the rebuilder if this is the case, someone didn't check it so what else could be missed? The endplay should be set to 0015-002" for maxium life and performance.

[Richard H.]

Re: Rear brake grind

Gary,

It is hitting on both ends of the caliber could both ends be bent?

Rich

Richard,
Sounds like the caliper bracket is bent,causing the caliper to be cocked on the mounting. Could be bent ear on the caliper but usually it's the bracket.
I check the brackets when I have them apart to see if they're bent, using a spindle press will bend them a lot of times.
With the rotor and caliper mounted I spot down and look at the caliper seam, it should be on center of the rotor, if it's bent you will see it taper off.
If the bracket is bent then you have to start all over, DO NOT attempt to reuse bearings once they're pressed off. Sometimes they can be used but most times they're going to get wrecked removing them. It's just not worth it not to use new bearings. I would be calling the rebuilder if this is the case, someone didn't check it so what else could be missed? The endplay should be set to 0015-002" for maxium life and performance.

[Wayne W.]

Re: Rear brake grind

Often happens when the Kent Moore tool is used to remove the axle, or the unit is put into a press.

[Gary R.]

Re: Rear brake grind

Richard,
I hope others don't mind I post pictures, but this may help you. This is what I'm talking about. This is a '66 arm with new rotor but original bracket. You can see the caliper is centered on the rotor. Does yours look like this?

[Michael W.]

Re: Rear brake grind

Is it possible that someone installed a front rotor instead of a rear? Are the adjusting holes for the p/brake present?

[Gary R.]

Re: Rear brake grind

Mike has a good point, and one that sometimes gets overlooked. Hope it's something simple like that.

I did find this picture of the bracket. This is on a set of offset arms but the bracket it a stock one.

[Richard H.]

Re: Rear brake grind

Before I remove the trailing arm I am thinking of trying to heat the bracket and tab it the little distance I need to clear the caliber? Is this worth a try? I am a backyard mechanic!

Rich

Gary,

It is hitting on both ends of the caliber could both ends be bent?

Rich

[Carl B.]

Re: Rear brake grind

I bent the caliper bracket with a spindle press. Remove spindle and replace caliper bracket. Spindle should be easy to remove 2nd time.

[Joe R.]

Re: Rear brake grind

Richard,

Call Bair's at 1 800 421-9644 and they will sell you a caliper bracket. They don't cost much and it's much safer than heating and bending your bracket again. You could put some small cracks in the bracket that might haunt you later.

I'm sure you can get the recommendation of several NCRS members that Bair's is the leader in trailing arm restoration.

JR

[Gary R.]

Re: Rear brake grind

I wouldn't attempt to bend it on the car or off. Can you determine if it's bent? If so the spindle assembly can be removed without removing the arm, but I would remove the arm and work on it on the bench.
If you want to remove the spindle assembly then you will have to remove the spindle flange, parking brakes and the 4 nuts on the studs. Since it's a new rebuilt arm it should come apart easy. You can then decide what you want to do to correct it, rebuild or swap out.