Brake pads rear

tdark

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#1
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MAKE:Chevy
MODEL:Corvette
YEAR:1990
MILES:55000
ENGINE:5.7
DESCRIBE ISSUE...brakes

question on this troublesome corvette that belongs to my cousin. This is the one that he could never get the brake light to go out and stay out last year. Each time the light would come on the master cylinder rod ( valve or whatever it is called ) would be off center. I give up for a while on that as I now have to take care of my wife and told him to just drive it for now.

He calls me today and asks me to come over a take a look at his rear brakes. He had new pads installed 5000 miles ago and the outside pad is worn to the metal. I thought maybe the slide pins were stuck but they did not appear to be.

I can only assist him on occasion because of the problem with my wife so maybe someone here can shed some light on what could have caused this. We have not yet looked at the other side yet. The right rear is the one with the issue. Inside pad looks like new. Outside is metal to metal and has begin to cut into rotor. I cannot decide if we need to order a rebuilt loaded pad - caliper assembly or maybe try to find out what happened to this one.
 

kev2

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#2
The brake rod off center - can you explain ? I added an attachment (#4) so others can follow...
Rear brake pad worn outside only? maybe the diagram (#3) will spark a thought ...
 

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#3
Looking at that caliper design, and assuming that the guide pins are moving freely...I see three best possibilities...
1. Outside pad was defective and wore down way too fast.
2. Inner pad is stuck in it's bracket and does not get pressed against rotor.
3. Parking brake cable housing is pulling caliper towards center of car and outer pad wore out.
 

tdark

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#4
The brake rod off center - can you explain ? I added an attachment (#4) so others can follow...
Rear brake pad worn outside only? maybe the diagram (#3) will spark a thought ...
 

tdark

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#5
I was referring to the master cylinder valve getting off center when. The proportion valve in master cylinder detects when things are not right meaning maybe more pressure to front or rear. The light will go off and stay off sometimes for 50 miles but it always comes back on. You can remove the sensor screwed in side of master cylinder when the brake light comes on and it will be always toward the rear.

We can center it with a small tool and the light will go off but soon come back on. We went over this last year here at BAT I think and I believe we decided it was the anti lock assembly behind seat that could be the problem. I don't think that has anything to do with the rear outside pad wearing to metal though.


Sometimes he can drive this car for a week and the light never comes on and then it may stay on for days. I told him to just drive it. I also suggested he remove the anti lock assembly and take it out of the picture by making lines to eliminate this but he never did that.

Someone here had suggested that we try that. I will have him remove the left rear to see if the outside pad is worn like right rear but he was too tired today to do that. Strange that the pins are free and nothing seems to be sticking but yet the outside right rear is down to metal and inside looks like new. This car had never had good brakes.

The 1989 C4 that I replaced the fuel pump on today had great brakes. It has not been run since 2008 but got it back going today and took a ride. Everything works great. That was in another post so I will not go into more on this. Tom
 

tdark

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#6
He just decided he would order rebuilt calipers from amazon , all hardware included. Got good quality pads also . He is not listen and do what all data said about the hand brakes. All is good but one thing. The hand brakes are way to tight. Cannot pull and get on click. I sent him instructions on how to release the cable before installing calipers but he did it his way. Now I got to help him figure out how to get some slack on the hand brakes. The rotors are way to tight. I did help him bleed it and now the rear brakes hold. Before they would never do that. Not sure exactly how we are going to get some slack on the brake cable but maybe I can get some time to help him tomorrow.
 

tdark

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#8
Perfect kev2, I can see the tool I need with the picture that is blown up. Same thing as releasing a Come-Along-Tool. It is so tight now I will probably have to remove the cable from the rear caliper. I could maybe just pull back on the pawl and hold it then have a helper pull the parking cable to the rear. He now just has it wound way to tight. He said he could not figure out it yesterday so maybe I can take time and help him sometimes this weekend. THANKS. Tom
 

nickb2

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#10
Step 5-8 are most important for a good finish to this job. The rest should adjust itself once the drive pawl is released and the caliper pistons homed in. This IS a two man job. ;)
 

nickb2

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#11
I think I may have misspelled. It is most important to have proper parking brake free travel. This is why that pad wore out prematurely. It was constantly loaded. You are lucky that disc did not get blue and warped. If the parking brake procedure is done in reverse, this will always be the result and no brake pads can resist that kind of drag.
 

nickb2

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#13