I live in New Zealand and I'm on my third Silverado. The reason for the query is that I have a problem with the front rotors overheating on my 2005 Chevy K1500 Crew Cab. The rotors develop "hot spots" that are blue, and even under light to moderate braking become extremely noisy with heavy vibration. I do a fair amount of towing. This truck has traveled 100,000km (60,000miles) and I'm already on my third set of brakes, requiring a fourth set. The original set lasted 20,000km (12,000 miles), then an after market set with pads were supplied (origin unknown) and they lasted 1,000km (600miles), if that. The third set of rotors and pads were supplied out of GM Canada and the same has happened but took a little longer.
I have had the vehicle over a brake machine to check the pressure differentials between front and rear. The fronts were 350 and rear 280 and by all accounts are within the parameters. I have been advised to replace with "drilled & slotted" rotors, but until I can get to the cause, it's a wasted exercise.
This was the first truck of this series that the conversion company had a disc-drum configuration. I do a fair amount of towing. I would be appreciative if you can shed some answers as to why.
Recheck the math. Lets say you did better than suggested and got about 12,000 miles out of each set of pads, and you're on the third set going on a forth. That would put your odometer at about 36,000 miles (about 60,000 km)?
Second: why are you replacing rotors every time as opposed to resurfacing them (usually get 2 or 3 cuts before reaching minimum thickness)?
And third, what's the conversion you're referring to? Did it add anything to the curb weight of the truck? If so, the extra weight will have an affect on the vehicle's maximum cargo and towing capacities. Adding to that equation, how much trailer weight are you pulling and cargo weight are you hauling? Exceeding any of the manufacturer's maximum capacities is going to wear out your brakes fast. As a matter of fact, even below the maximum capacities, more weight is always harder on the brakes.
Normal lifespan of brakes has always been a gray area due to the variables. Not just because of the weight you're lugging, but also the driving habits involved. I've seen two identical vehicles, no load and mechanically correct, where the front brakes on one lasted half as long as the other, due only to the people behind the wheel.
12,000 miles on a pair of half-ton front brake pads is considered a short lifespan, but almost within a normal range. When saying the brakes are gone, we mean the front pads are down to the wear indicators and/or only a few millimeters of lining remain. Often a pulsation from the pedal while braking due to warped rotors will appear long before the pads are worn out (you can resurface rotors without replacing the pads). Getting hot spots on the rotors and pads wearing out in only 600 miles (if that's actually the case) tells me there's a major problem that should be obvious to you and/or a capable technician.
Either you're drag racing while pulling a house, or there's a significant mechanical failure being missed. You've eliminated front-to-rear brake pressure differential being out of specifications as a problem. So I'd be looking for a continuous drag on the front brakes, or perhaps airflow to the brakes being blocked by the mystery conversion package, be it custom wheels or forward body modifications.