turn rotors or replace them?
Thread Starter
Intermediate
Joined: Apr 2003
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From: Palmyra PA
turn rotors or replace them?
Had new calipers for several thousand miles now. Left rear is leaking fluid between inboard pad and caliper so I assume the pistons are being pumped from rotor runout. I don’t have a gauge or care to take her to a garage to check the rotors on the car. Is it worth removing them and getting them turned or should I just replace them? I drilled the rivets out already. What would be the issue with the caliper then? Is a boot generally torn or will a corrected rotor solve the leak? It's a new one, stainless sleeves. Havn't removed anything yet but am surprised I have a leak after only 3k miles over two years.
Tech Contributor
Joined: Aug 1999
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From: Connecticut, USA
Re: turn rotors or replace them? (drs80vette)
It's almost impossible to do an accurate brake job and not check runout,especially on the rear system. If you have over .005" runout then you could get air pumping but you're experiencing leakage. I would first get the caliper fixed. Where did you get it,you may be able to exchange it. There are a lot of machine shops that jumped on the band wagon when SS sleeved calipers came out about 25 years ago. Some of this shops did poor work,some may still be in business?
Once you get the calipers sealed then look at the rotors. Did you mark the position of the rotor to a wheel stud so you know the orientation to put it back? Turning the rotor independent of the spindle will not give a true concentric reading-you'll still have runout. Replacing the rotor with a new USA made one will also not garantee little or no runout. The last new,(USA),rear rotor I installed had .004-.005" runout. I had to shim it get it down to .0005"-.001" But again if you don't use an indicator you'll be wasting your time.
Gary
Once you get the calipers sealed then look at the rotors. Did you mark the position of the rotor to a wheel stud so you know the orientation to put it back? Turning the rotor independent of the spindle will not give a true concentric reading-you'll still have runout. Replacing the rotor with a new USA made one will also not garantee little or no runout. The last new,(USA),rear rotor I installed had .004-.005" runout. I had to shim it get it down to .0005"-.001" But again if you don't use an indicator you'll be wasting your time.
Gary
Thread Starter
Intermediate
Joined: Apr 2003
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From: Palmyra PA
Re: turn rotors or replace them? (gtr1999)
Sounds like I need to check run out with rotor on car. You are correct about fixing the caliper first. I will take it to the part store where I bought it a couple of years ago and see what I can do. I may have a good chance on getting a replacement due to my relationship with the owners. If not is it worth buying a seal kit for a repair?
Once I get the caliper repaired, I will indeed take it to a garage to check runout issues. When I purchased the car back in '99 this same wheel was an issue. As far as marking wheel to hub, I do that but I recently had it inspected and I bet they did not pay attention to that detail.
Once I get the caliper repaired, I will indeed take it to a garage to check runout issues. When I purchased the car back in '99 this same wheel was an issue. As far as marking wheel to hub, I do that but I recently had it inspected and I bet they did not pay attention to that detail.
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 32
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From: Palmyra PA
Re: turn rotors or replace them? (gtr1999)
Actually I was mentioning the tire to rotor which I also mark but that shouldn't be an issue. Whenever I pull rotors I indeed mark them so I should be ok there. I will just need to get the runout gauged after the caliper repair.
Le Mans Master
Joined: Aug 2000
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From: Austin TX
Re: turn rotors or replace them? (drs80vette)
IMHO, THE solution to leaking calipers and air pumping is a quality set of sleeved calipers with Zero Tolerance O ring pistons. I did this about 5 years ago and have had no problems since.
Race Director
Joined: Dec 2000
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From: CO
Re: turn rotors or replace them? (drs80vette)
just a bit of info. I turned my rotors at all 4 corners and haven't had a bit of trouble with runout. I however did not check runout and for all I know it may be in spec.
A leaky caliper may just be that. A leaky caliper. May or may not have been caused by runout. :confused:
A leaky caliper may just be that. A leaky caliper. May or may not have been caused by runout. :confused:
