I have a guy at work that reckons whenever you change your pads you need to machine your discs at the same time otherwise you will chew out your pads alot faster.
 
True or False?
 

Also anyone try EBC 'yellow stuff' brake pads?

Pfft, changed many a pad without machining rotors and not had any issues so far.  That being said all my rotors have been in good nick, and not grooved and rough.
 
Way back in the day when I worked for Holden/Nissan we used to simply change the pads and give 'em a bleed.
 
I have heard other people say, you can't change rotors and pads at the same time.  I'm not sure if there's any truth in this though.  I have also done this a few times and had no issues either.

New pads won't make any difference, though it is true that regular machining can help with brake wear.
Due to heat effects, parts of the disc can become harder than normal. The surrounding areas will wear away quicker, so you get a disc face that is no longer flat. This will only get worse if not machined, until you can get significant vibrations when using the brakes and you'll chew through the pads quicker.
Its what a lot of people blame on 'warped discs'.

i though you always had to machine for a flat surface before changing pads, if thats the case then ill get some new brake pads to use on my car.

Its not necessary to machine rotors but a good idea and dose not cost a lot. That's if they are still above the minimum thickness
 
If you but new rotors on defiantly use new pads

blacky83
New pads won't make any difference, though it is true that regular machining can help with brake wear.
Due to heat effects, parts of the disc can become harder than normal. The surrounding areas will wear away quicker, so you get a disc face that is no longer flat. This will only get worse if not machined, until you can get significant vibrations when using the brakes and you'll chew through the pads quicker.
Its what a lot of people blame on 'warped discs'.

I agree. Many so called 'warped' discs are not warped.
I had annoying  brake shudder under heavy braking, and eventually found a couple of my  rotors had small radial cracks, so it would have been a waste of time machining them anyway.
Fitted new rotors and pads - problem fixed.
 

Old rotors are fine as long as they're in good nick. It's a good idea to rub them down with some sandpaper before installing new pads. Removes the old pad transfer layer so you're back to bare metal for the new pads and scuffs up any shine or glazing you might have.

Ebc yellows are good. Had them on the front for almost a year now and still heaps of meat left. In that time I've done more than 5 track days and the pads have always been good. No fade even after 5 laps or more and they work great even when cold. Feel just like any other pad. Once warm they stop even better. Pretty dusty though so if you wont track them then ebc reds would probably be better.