Resurfacing Rotors
07-07-2003, 04:57 PM
#1
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Resurfacing Rotors
Howdy guys! I've done a couple of searches to no avail, so excuse me if the subject has been dealt with previously.
I'm about to replace the front brake pads on my 2000 Subaru Outback Sedan. On my Landcruiser, the general consensus is to not turn the rotors prior to replacing the pads, due to a tendency for the factory rotors to warp once they're turned.
If the Subaru rotors are in good condition, with no grooves, glazing, etc. is it recommended to have them turned, or can I just replace the pads?
Thanks ahead of time. Hopefully I'll be hanging out here more often!
-H-
I'm about to replace the front brake pads on my 2000 Subaru Outback Sedan. On my Landcruiser, the general consensus is to not turn the rotors prior to replacing the pads, due to a tendency for the factory rotors to warp once they're turned.
If the Subaru rotors are in good condition, with no grooves, glazing, etc. is it recommended to have them turned, or can I just replace the pads?
Thanks ahead of time. Hopefully I'll be hanging out here more often!
-H-
07-07-2003, 05:42 PM
#2
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Join Date: Nov 2002
Location: Santa Clara CA USA
Posts: 1,253
Car Info: 96 Chevy Impala SS, 06 GMC 2500HD (former 02 WRX)
Turning rotors is basically a big scam. It makes them thinner, without really SOLVING the issues that it is supposed to fix!
You're better off putting a non-directional surface on them, then bedding in the new pads properly. To do this, take a round sanding disk in a drill and basically "scuff up" the rotor surface. Don't need to take much material off, just break the grooved pattern in the surface. Clean them WELL afterwards (figure on a couple cans of brake cleaner, minimum, for 4 rotors) and reinstall.
You're better off putting a non-directional surface on them, then bedding in the new pads properly. To do this, take a round sanding disk in a drill and basically "scuff up" the rotor surface. Don't need to take much material off, just break the grooved pattern in the surface. Clean them WELL afterwards (figure on a couple cans of brake cleaner, minimum, for 4 rotors) and reinstall.
07-09-2003, 03:31 AM
#3
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Machining the rotors is the most important part and the one of the most overlooked and under rated part of a good brake job. Especially on a subaru.
The rotor gets warped, and devellops variable rotor thickness (diff thicknesses over the surface of the rotor). They become glazed. The resin from the old pads gets laid down on the rotor. The new pads won't bed into the rotor properly. Sure you loose a bit of rotor material but its a small price to pay compaired to the problems you might/will get.
Problems like noise/squeeks (especially under light braking), uneven braking, pulsing pedal, jiddering (the sensation of the brakes grabbing and releasing).
Prep work is a must. Prior to machining, Sand of any rust thats in the rotor hat, the part that sits on the hub and the top of the hat, the face that gets clamped in the lathe. Also any rust on the hub face itself.
Once rotors are machined, wash them in water or with brake cleaner. This will remove the metal and graphite particals and stop them getting into your new pads.
I also find the rear brakes on the subbies warp more than the front and I've needed to machine them twice.
Most important, The wheel nuts need to be torqued to the manufactures specifications. I recommend to tighten them gradually like you would a head onto a block. If you haven't got a torque wrench, beg, borrow or steal one if you have to. If You tighten one nut up to the max poundage in one go you run the risk of creating a high spot on the rotor and other problems will start to occur.
I hope this quick guide helps.
The rotor gets warped, and devellops variable rotor thickness (diff thicknesses over the surface of the rotor). They become glazed. The resin from the old pads gets laid down on the rotor. The new pads won't bed into the rotor properly. Sure you loose a bit of rotor material but its a small price to pay compaired to the problems you might/will get.
Problems like noise/squeeks (especially under light braking), uneven braking, pulsing pedal, jiddering (the sensation of the brakes grabbing and releasing).
Prep work is a must. Prior to machining, Sand of any rust thats in the rotor hat, the part that sits on the hub and the top of the hat, the face that gets clamped in the lathe. Also any rust on the hub face itself.
Once rotors are machined, wash them in water or with brake cleaner. This will remove the metal and graphite particals and stop them getting into your new pads.
I also find the rear brakes on the subbies warp more than the front and I've needed to machine them twice.
Most important, The wheel nuts need to be torqued to the manufactures specifications. I recommend to tighten them gradually like you would a head onto a block. If you haven't got a torque wrench, beg, borrow or steal one if you have to. If You tighten one nut up to the max poundage in one go you run the risk of creating a high spot on the rotor and other problems will start to occur.
I hope this quick guide helps.
07-20-2003, 07:49 AM
#4
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Join Date: Dec 2002
Location: up in my hizzy
Posts: 30
Car Info: Blue sedan WRX
dont bother turning rotors
if you rotors are in GOOD shape at the time of changing the pads, dont bother machining them. you want a clean suface for the new pads. so lightly sand the rotor surface with 250 grit, slap on the pads and drive. well actually, bed them in first. i used to turn my rotors, and had a lot of warping problems (too thin).
i have done this on Jeeps, BMW, VWs, and subarus without any problems.
i think a better rule of thumb is to only use 2 sets of pads over the lifetime of the rotor. when you change your pads, even if you have a big gouge in the disc from the previous pad's metal backing plate, the pad will just contact the high spots for a day or two, them it will fit fine ( fully contact the disc). ever heard of slotted rotors? same difference. just my 2 cents and personal experience.
i have done this on Jeeps, BMW, VWs, and subarus without any problems.
i think a better rule of thumb is to only use 2 sets of pads over the lifetime of the rotor. when you change your pads, even if you have a big gouge in the disc from the previous pad's metal backing plate, the pad will just contact the high spots for a day or two, them it will fit fine ( fully contact the disc). ever heard of slotted rotors? same difference. just my 2 cents and personal experience.
07-21-2003, 11:47 AM
#5
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Join Date: Dec 2002
Location: San Diego, Ca
Posts: 128
Car Info: Still Looking
I always get my rotors cut when I get new brake pads. I've never done any other way. I was just tought to cut the rotors each time I get new pads that way it would apply even contact to the pad when it touchs the roter and allow it wear evenlly. I've never had a problem doing it that way. I have had more problems with getting warped rotors when I buy new ones from kragen or autozone. But im not an expert.
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