Need help with rear rotor
Thread Starter
6th Gear
Joined: Oct 2010
Posts: 6
Likes: 0
Need help with rear rotor
I just bought my first Corvette, a 1980. We decided to do the brakes soup to nuts, new master cylinder, ss lines, new calipers. The first 3 wheels were a breeze, but when we got to the right rear, we found that it was the original riveted rotor; the brakes had never been done. We spent two days pounding on it before we gave up. Ended up replacing the whole trailing arm assy and rotor with a new one from Duntov. We opted for the non-riveted version because it seemed more sensible, but now I'm wondering if we made a mistake. The rotor goes on easily enough, but it just doesn't seem to be seated correctly. When the caliper is bolted on, it seems like it's at an angle. What can the problem be?
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
I just bought my first Corvette, a 1980. We decided to do the brakes soup to nuts, new master cylinder, ss lines, new calipers. The first 3 wheels were a breeze, but when we got to the right rear, we found that it was the original riveted rotor; the brakes had never been done. We spent two days pounding on it before we gave up. Ended up replacing the whole trailing arm assy and rotor with a new one from Duntov. We opted for the non-riveted version because it seemed more sensible, but now I'm wondering if we made a mistake. The rotor goes on easily enough, but it just doesn't seem to be seated correctly. When the caliper is bolted on, it seems like it's at an angle. What can the problem be?
But, you should make absolutely sure thats a rear rotor and not a front or the pads will not fit.
Thread Starter
6th Gear
Joined: Oct 2010
Posts: 6
Likes: 0
It doesn't seem like the rotor is seated on the hub correctly, and the caliper is a little cocked. The front pad is lower than the rear pad. The center of the left rear hub sticks out more than on the new one.
Burning Brakes
Joined: Oct 2003
Posts: 1,090
Likes: 74
From: New Carlisle IN
Tighten your lug nuts against the rotor to seat it (may need a spacer between lug and rotor) and then look at your alignment. The lugs are what holds the rotor against the hub, sandwiched between your wheel and hub.
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Still sounds like the wrong rotor. Remove the pads and bolt everything up using the lug nuts to hold the rotor tight. Turn the lug nuts around backwards to protect the rotor. Then take a look at how the rotor is centered in the caliper. My bet is it will be way off to one side.
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Thread Starter
6th Gear
Joined: Oct 2010
Posts: 6
Likes: 0
We finally got back out to the garage. It definitely is a rear rotor, not a front one. We took the left rear rotor off and tried to put that on the right, but it doesn't fit either. My boyfriend now thinks the rotor might possibly be for a different model year?? I got a message from someone at Duntov who saw this thread, he sent his phone number and told me to call if we can't figure it out. Now that is great customer service......
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
We finally got back out to the garage. It definitely is a rear rotor, not a front one. We took the left rear rotor off and tried to put that on the right, but it doesn't fit either. My boyfriend now thinks the rotor might possibly be for a different model year?? I got a message from someone at Duntov who saw this thread, he sent his phone number and told me to call if we can't figure it out. Now that is great customer service......
Burning Brakes
Joined: Oct 2003
Posts: 1,090
Likes: 74
From: New Carlisle IN
If the rotor from the left side fit on the left side, but the same rotor doesn't fit on the right side, there must be something wrong with the right side and not the rotor. It could be the hub screwed up not mounting the rotor correctly, or it could be the caliper bracket is bent like wombvette said.
Thread Starter
6th Gear
Joined: Oct 2010
Posts: 6
Likes: 0
Here is the latest theory. Last night we laid both rotors on the floor side by side and measured everything. The ID of the new rotor is about 1/8" less than the old one, just enough to keep it from seating completely. It's just catching the pads, which are dialed all the way in. The rotor looks like it was rough machined, the inside surface is not very smooth. I'm thinking of having it cut locally vs paying to ship it back. Also tried the left rotor on the right side again, it seems to be catching on one of the lugs, and changing the rotor position doesn't help. I'm not worried about it, the old rotor fits the old trailing arm, I just need to get the new rotor to fit.