charbilly2001
Mar 25th, 04, 2:35 PM
1970 Chevelle 4Dr. 350/350 Relatively stock.
I am having a couple problems with my brakes that I would like comment on from the gang.
I recently had a complete brake job done on my Chevelle including new rotors , drums , hardware and hoses. After the front pads were bedded in I noticed a circumferential blue band on the rotor faces about 3/4 inch wide obviously caused by a less than full contact between pad and rotor. I was under the impression that rotor/pad contact was generally not an issue since they are usually designed for full contact from the gitgo as a function of normal quality control.
The issue is complicated however by the fact that the old rotors also had that same blue band accompanied by severe heat checking of the rotor faces within that same 3/4 inch band and the old rotors were uncut. Outside of the banded area the rotors showed only normal wear. I installed them brand new when I bought the Chevelle. On other cars I have had I have seen bluing of rotors but its been the entire swept surface of the rotor not just a portion as is the case with my Chevelle.
The other problem I am having with my brakes is that when coming to a stop from normal surface street speeds I notice that the vacuum boost seems to fade badly. I have normal engine vacuum with no apparent leaks. No hissing inside the car indicating a perforated diaphragm. At all other times the brakes work properly. Recently I read another post that discussed pedal effort as a function of master cylinder piston diameter. I installed a reman master cylinder some time ago and I have no idea if the remanufacturer paid any attention to that particular issue.
If I was sold a reman master cylinder that was bored oversize then that could contribute to my increased pedal effort or there may also be a connection between insufficient rotor/pad contact and the increased pedal effort.
Any thoughts on this situation would be appreciated
Thank you , Bill
I am having a couple problems with my brakes that I would like comment on from the gang.
I recently had a complete brake job done on my Chevelle including new rotors , drums , hardware and hoses. After the front pads were bedded in I noticed a circumferential blue band on the rotor faces about 3/4 inch wide obviously caused by a less than full contact between pad and rotor. I was under the impression that rotor/pad contact was generally not an issue since they are usually designed for full contact from the gitgo as a function of normal quality control.
The issue is complicated however by the fact that the old rotors also had that same blue band accompanied by severe heat checking of the rotor faces within that same 3/4 inch band and the old rotors were uncut. Outside of the banded area the rotors showed only normal wear. I installed them brand new when I bought the Chevelle. On other cars I have had I have seen bluing of rotors but its been the entire swept surface of the rotor not just a portion as is the case with my Chevelle.
The other problem I am having with my brakes is that when coming to a stop from normal surface street speeds I notice that the vacuum boost seems to fade badly. I have normal engine vacuum with no apparent leaks. No hissing inside the car indicating a perforated diaphragm. At all other times the brakes work properly. Recently I read another post that discussed pedal effort as a function of master cylinder piston diameter. I installed a reman master cylinder some time ago and I have no idea if the remanufacturer paid any attention to that particular issue.
If I was sold a reman master cylinder that was bored oversize then that could contribute to my increased pedal effort or there may also be a connection between insufficient rotor/pad contact and the increased pedal effort.
Any thoughts on this situation would be appreciated
Thank you , Bill