Original Rotors
#1
Racer
Thread Starter
Original Rotors
I completed a 4 wheel disc brake job, new rotors, pads, rebuilt my calipers, new brake lines and MC after completing replacement of all front end suspension parts on my 1981 vette.
The rotors taken off were original, fronts were still riveted on. The original rotors are smooth except for right front has a slight groove and all would need to be turned. Is it worth keeping, selling or just scrap?
The rotors taken off were original, fronts were still riveted on. The original rotors are smooth except for right front has a slight groove and all would need to be turned. Is it worth keeping, selling or just scrap?
Last edited by Reaper19; 01-29-2018 at 10:21 AM.
#2
Le Mans Master
They have to be measured to determine if the rotors are thick enough to turn. If not they are boat anchors. If in spec after turning someone might want them. I wouldn't spend a lot of money turning them though.
I find myself in the same boat here. Mine are headed to the scrap yard.
#3
Nam Labrat
Member Since: Sep 2013
Location: New Orleans Loo-z-anna
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FYI:
If the rotor faces are within run-out tolerances you may not need to "turn" them because of a small groove.
ALSO:
The rotors can be "de-glazed" by removing the caliper and spinning the rotor on the spindle and holding a spinning sanding disc gently against them that is turning in the opposite direction.
Gently move the spinning disc across the entire flat surface of the rotor until a clean surface is obtained.
Do the same procedure to the other side of the rotor.
A small angle grinder with sanding disc against rotor surface.......
A large grinder with thick "rubber disc" installed to spin rotor by holding grinder in place against rotor edge using C-clamps on the frame or other area.........
If the rotor faces are within run-out tolerances you may not need to "turn" them because of a small groove.
ALSO:
The rotors can be "de-glazed" by removing the caliper and spinning the rotor on the spindle and holding a spinning sanding disc gently against them that is turning in the opposite direction.
Gently move the spinning disc across the entire flat surface of the rotor until a clean surface is obtained.
Do the same procedure to the other side of the rotor.
A small angle grinder with sanding disc against rotor surface.......
A large grinder with thick "rubber disc" installed to spin rotor by holding grinder in place against rotor edge using C-clamps on the frame or other area.........
#4
Melting Slicks
Agree and great advice here!
FYI:
If the rotor faces are within run-out tolerances you may not need to "turn" them because of a small groove.
ALSO:
The rotors can be "de-glazed" by removing the caliper and spinning the rotor on the spindle and holding a spinning sanding disc gently against them that is turning in the opposite direction.
Gently move the spinning disc across the entire flat surface of the rotor until a clean surface is obtained.
Do the same procedure to the other side of the rotor.
A small angle grinder with sanding disc against rotor surface.......
A large grinder with thick "rubber disc" installed to spin rotor by holding grinder in place against rotor edge using C-clamps on the frame or other area.........
If the rotor faces are within run-out tolerances you may not need to "turn" them because of a small groove.
ALSO:
The rotors can be "de-glazed" by removing the caliper and spinning the rotor on the spindle and holding a spinning sanding disc gently against them that is turning in the opposite direction.
Gently move the spinning disc across the entire flat surface of the rotor until a clean surface is obtained.
Do the same procedure to the other side of the rotor.
A small angle grinder with sanding disc against rotor surface.......
A large grinder with thick "rubber disc" installed to spin rotor by holding grinder in place against rotor edge using C-clamps on the frame or other area.........
On the last set of front riveted rotors I had, I checked the runout and minimum thickness, cleaned everything several times with brake cleaner, hand sanded thoroughly with 80 grit (doorgunner's plan is likely better), new pads and broke them in with several reasonably strong stops from 30 to zero and they worked great. IMHO, few small grooves do not matter. And a friend told me they can turn them on the spindle installed now for reasonable cost, but I would not turn them unless they do not pass the tests above.
Hope this helps and good luck.
Last edited by 20mercury; 01-29-2018 at 12:02 PM.
#5
Team Owner
The quality of the original rotors is much better than what you can buy at your local parts store. Yes, there are high quality vendors out there; but their products are much more expensive than having the original rotors turned. For a normal street vehicle, the stock rotors are more than you need and, as evidenced by how they look after 40+ years, they will last a long time if the braking system is well maintained.
#9
Nam Labrat
Member Since: Sep 2013
Location: New Orleans Loo-z-anna
Posts: 33,897
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You just reminded me that I had to resurface the mating faces of two sets of calipers. The pads were well worn at the tops and barely worn at the bottoms because the caliper halves were not machined parallel to each other from the factory. All is well now.
#11
Drifting
The quality of the original rotors is much better than what you can buy at your local parts store. Yes, there are high quality vendors out there; but their products are much more expensive than having the original rotors turned. For a normal street vehicle, the stock rotors are more than you need and, as evidenced by how they look after 40+ years, they will last a long time if the braking system is well maintained.
I agree with 7T1vette. I replaced all four rotors on my 68 with drilled cryo treated rotors. The old ones were in perfect condition- much better steel used than is used today.