Overlooked part of rotor replacement
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From: Jersey Shore
Overlooked part of rotor replacement
Here is something often overlooked with rotor replacement. You have to clean up the hub before you put the new rotor on. With that amount of rust on the hub the rotor will may not sit perfectly flat against the hub surface. The rotor will then wobble back and forth in the caliper like a bent rim on a bike, I am exaggerating with the bike rim analogy here to make a point. The brake pads will then leave thicker deposits on certain parts of the rotor and brake shudder will eventually occur. Leading most to believe that the rotors must be turned. Then you will turn the rotor and put it right back on the rusty hub, and the same thing will happen again. The best way to turn the rotor is with an on-car-lathe, which turns the rotor while it is still on the car. Then the rotor will be turned perfectly straight in relation to the caliper even if it is sitting slightly uneven on the hub.
The first part to a successful brake job is getting those rotors straight and true. The rotors on these cars are pretty big and even the slightest out-of-true condition of the rotor will eventually lead to brake shudder. I think the runout spec in the shop manual is something crazy like .0014" for the front rotor!! The shop manual calls for checking the runout with a dial indicator and then if it is out of spec you can try to rotate the rotor on the hub to a different position to recheck the run-out.
So many people suffer with brake shudder issues and this is where it all starts.
The first part to a successful brake job is getting those rotors straight and true. The rotors on these cars are pretty big and even the slightest out-of-true condition of the rotor will eventually lead to brake shudder. I think the runout spec in the shop manual is something crazy like .0014" for the front rotor!! The shop manual calls for checking the runout with a dial indicator and then if it is out of spec you can try to rotate the rotor on the hub to a different position to recheck the run-out.
So many people suffer with brake shudder issues and this is where it all starts.
Here is something often overlooked with rotor replacement. You have to clean up the hub before you put the new rotor on. With that amount of rust on the hub the rotor will may not sit perfectly flat against the hub surface. The rotor will then wobble back and forth in the caliper like a bent rim on a bike, I am exaggerating with the bike rim analogy here to make a point. The brake pads will then leave thicker deposits on certain parts of the rotor and brake shudder will eventually occur. Leading most to believe that the rotors must be turned. Then you will turn the rotor and put it right back on the rusty hub, and the same thing will happen again. The best way to turn the rotor is with an on-car-lathe, which turns the rotor while it is still on the car. Then the rotor will be turned perfectly straight in relation to the caliper even if it is sitting slightly uneven on the hub.
The first part to a successful brake job is getting those rotors straight and true. The rotors on these cars are pretty big and even the slightest out-of-true condition of the rotor will eventually lead to brake shudder. I think the runout spec in the shop manual is something crazy like .0014" for the front rotor!! The shop manual calls for checking the runout with a dial indicator and then if it is out of spec you can try to rotate the rotor on the hub to a different position to recheck the run-out.
So many people suffer with brake shudder issues and this is where it all starts.
The first part to a successful brake job is getting those rotors straight and true. The rotors on these cars are pretty big and even the slightest out-of-true condition of the rotor will eventually lead to brake shudder. I think the runout spec in the shop manual is something crazy like .0014" for the front rotor!! The shop manual calls for checking the runout with a dial indicator and then if it is out of spec you can try to rotate the rotor on the hub to a different position to recheck the run-out.
So many people suffer with brake shudder issues and this is where it all starts.
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Registered User
Joined: Jan 2011
Posts: 109
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From: Jersey Shore
You should try to clean the rust off with sandpaper or a whiz wheel. The hub surface is actually machined and cleans up pretty easily. 3M actually makes a bit/tool that you chuck into a drill and it fits around the stud so you can clean real close to the stud, but I never used it.
Thread Starter
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Registered User
Joined: Jan 2011
Posts: 109
Likes: 2
From: Jersey Shore
That is not my car. It is a picture I took from another thread. However my car is also very rust free as it spent most of its life in Texas. Also hose the **** out of it during the winter to get the salt off.
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