i was argueing with some guy today, that you need to turn your rotors everytime you replace brake pads. i do brake jobs all the time at work and have never changed pads without turning the rotors, thats what i was taught in school and have always done it that way.. just curious if you guys turn yours everytime or not?

 

Here's what Honda said in their July 95 service news:

When to RefinishBrake Discs

When brakes are subjected to “ordinary” usage, it’s
usually not necessary to refinish the discs when you
replace brake pads. This is good news for customers,
especially with all the hoopla these days about reducing
the cost of routine maintenance. However, there are
certain circumstances where you must refinish the brake
discs (using only your Kwik-Way or Snap-on on-car brake
lathe, of course).

Brake judder is caused by variations in brake disc
thickness. (The disc should be the same thickness all the
way around.) As little as 0.015 mm (0.006 in.) variation
in thickness can be felt as judder. To prevent comebacks
after brake pad replacement, ask the customer if he
regularly experiences steering wheel oscillation when
braking. If the answer is yes, refinish the discs.

Tapered or dished discs occur because discs seldom
wear evenly. (The inner surface will wear thinner or
thicker than the outer surface.) When new pads are
installed on tapered discs, the brake pedal will feel
spongy until the pads wear to match the shape of the
disc. Excessive taper also increases the amount of pedal
effort it takes to stop the car. Refinish the discs to
correct excessive taper.

Grooved discs (shallow grooves) are usually the result of
non-asbestos brake pads rubbing against the iron discs,
and are nothing to worry about. Refinishing the discs will
remove the grooves, but they’ll reappear as the new pads
and refinished discs wear. If the grooves are caused by
metal-to-metal contact, then you should refinish the discs.
If the grooves are deep, the brakes will feel spongy and
the pedal effort will be high until the new pads wear to
match the discs. Refinish the discs for deep grooves; don’t
refinish the discs for shallow grooves.

 

its always better to resurface the rotor at pad change, eliminating chance of pulsation

in the automotive industry, you dont want customers coming back saying, " my brakes pulsate now after you changed my pads..."

 

Yep. When I work on someone else's car I ALWAYS resurface the rotors, for the very reason EJ mentioned, plus you want the customer's pads to last a good long time. Now when I do my own brakes at the shop or at home, I don't always turn the rotors. I only turn them when I feel any pulsing, diving, or uneven wear.

 

I almost never have mine turned and almost never have a need for it. But I always bed new pads into the rotors, and never buy cheap pads that claim there is no break-in period.

And my dad argues and argues with me but I have nearly as much experience as he does now.