Break disk question.

car is mazda6 wagon 2005 (full option)
 
and ran 60000km so far.
 
i have a question about disk break..
 
when is the best time(km) to change the disk of the break?
 
i know it depends..but i want to know the general period..
 
i saw the disk today and it worn out quite a lot i think..
 
any recommendation about good disk, and pads?(brand name, etc)
 
thanks.
 
 

I check my fronts every 20,000 miles or so, the rears every 40,000.  Fronts wear faster than the rears do.

Ended up replacing all 4 corners at 50,000 miles.  Fronts needed it, rears were getting close.
 
2mm is the minimum pad thickness (pull the pads out and measure from the backing plate to the face of the pad, should be more than 2mm, if less than 2mm (or getting close) replace the pads.  If the rotors don't have grooves in them, you can have them turned down to a fresh surface at just about any autoparts store for around $12/rotor.

This is on my wife's Mazda6 wagon.  I used all Mazda factory parts.

My front pads made it just short of 40k miles. The rears are still original, and the car has just over 44k on it now. Just FYI.
 
David