I'm not sure that I would go 100k miles on a brake system without it at least being looked at. On the 99, 2 disc and 2 pad, or 4-wheel disc? Is that even an option in 99? Either way, that's a lot of miles to go without having anything done to them.
What? Do you mean back brakes? Front brake pads will last between 18,000 and 24,000 miles depending on how much highway driving you do. Back you should get around 75,000 or a more again depending on where you drive. If you have 100,000 miles on the back brakes, they need to be cleaned, and replaced.
I've gone a lot of miles on front disk brakes before without needing them to be changed. Especially in manual-tranny rig and I was just taught to use the engine to slow down not the brakes so much. I'm very light on the brakes.
Arnie's right, especially he front brake pads should go every 18-24k and turn the rotor if needed. Have them look at the calipars to see if they're still good while they're at it. (although, if you ask they will probably try to replace them.....)
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