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Replacing brake pads without surfacing rotors.

Skylarking

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Your pads lay down material into the rotor during the bedding in process which allows the brakes to work at their maximum efficiency.

So if your new pads are the same compound as the old pads, and the rotor is running true without thickness variations or gouges, then there is no real need to lightly skim the rotor. Still, I always run some emery cloth over the rotor to remove any glaze.

But if your rotors are gouged or have a large lip or you use different pad material, I’d skim the rotors as little as possible before measuring them up. Then if they are at or below minimum thickness, I’d replace them, or if above minimum then also run some emery cloth over the rotor face.

@hademall, I think pad slapped means just pulled old pads out and put new pads in (as you see at Bathurst).
 

hademall

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Your pads lay down material into the rotor during the bedding in process which allows the brakes to work at their maximum efficiency.

So if your new pads are the same compound as the old pads, and the rotor is running true without thickness variations or gouges, then there is no real need to lightly skim the rotor. Still, I always run some emery cloth over the rotor to remove any glaze.

But if your rotors are gouged or have a large lip or you use different pad material, I’d skim the rotors as little as possible before measuring them up. Then if they are at or below minimum thickness, I’d replace them, or if above minimum then also run some emery cloth over the rotor face.

@hademall, I think pad slapped means just pulled old pads out and put new pads in (as you see at Bathurst).
Ta.
 

Ron Burgundy

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If you are not machining the rotor the general rule is to use the same pads or more agressive pads. I.e. You would not put ceramic pads on braking system that had semi metalic without skimming the rotors.

In saying this, in past 15 yrs I never machined rotors. They are so afordable now that I just replace rotors every few years...or if they still have heaps left I put the same type of pads on...
 

Banjo79

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Bendix Ultimates and A1rm's both had pretty much chewed DBA 4000's by the time the pads were done. I never measured, but there was a good sized lip and the surface slots were getting pretty shallow. Definately not worth machining. That was with 2/1 piston brakes.
 

losh1971

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Ultimates chew out rotors regardless. They are not really a street pad, as they are designed for constant hard braking.
 

losh1971

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Routine machining is a wank that just adds $$ to the bill. Unless there's a vibration I wouldn't waste my time, or money!
The issue is that sometimes they won't vibrate until the new pads are fitted, as has happened with me on a couple of occasions. My old garage would always machine autos, my local now tends not too unless asked, regardless of the trans.
Personally I prefer to not take the chance for the extra $50 it costs.
 

J_D 2.0

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Machining down to minimum thickness (as policy) is a crime. The rotor is a heat sink, removing metal reduces it's ability to absorb and shed heat. Avoid that shop at all costs.
Trying to drum up more business the dodgy way!
 

J_D 2.0

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you can buy the parts what ever brand you like and get the shop to fit them because you can get some really good deals online right now with stock take sales or best is the black friday deals and i prefer new to machining
I’ve never bother getting discs machined on a Commodore. Brand new discs are cheap enough to not bother with machining.
 
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