Thread: Replacing Brake Rotors - any tips/tricks?

Originally Posted by pdd1098

You should never use old pads on new rotors, (they will introduce an uneven wear pattern in the new surface) the hiss is the gases disapating through the holes and slots, so your fancy rotors are doing their job
Another point is if you drive in mud a lot, slotty drilly rotors are bad as they can trap grit and chew up your pads real quick
Dave

I strongly disagree, it is preferable to use old pads with new rotors for several reasons.

1. New cast iron is 'green' and needs a few good heat cycles to work out internal stresses and condition the face.
It's also quite porous.

2. New pads contain the resins and binders from manufacture, these need to be burned out before optimum performance is reached.

If using brand new discs, these will be deposited onto and into the rotor and may lead to glazing.

For pads to work properly some material transfer takes place onto the rotor face, this can be hard to achieve and can take many thousands of km if the surface is clogged with the binders from new pads.

I realise it's impossible in some situations to not have a new/new setup, eg. when buying a new car, but I've never had uneven rotor wear when using new discs/old pads.

the bendix 4WD pads have sandpaper type stuff on the surface to enable very quick bed in and cleaning of teh discs.
Regards Philip A

Once fitted go to a lonely road and get the old girl up to 100 and then brake as hard as you can,do that a few times and you'll never have glazing. Pat