100k Maintenance?

edatlanta wrote:
I changed my serpentine belt and idlers at 100,000 just to be safe and keep the removed belt in a plastic bag under the seat if ever needed in the middle of nowhere.

Good advice. For some reason idler pulleys on GM's seem to be a fairly common failure point.

Advice to flush coolant is a good one. Dexcool is fine as long as you maintain it, and at 5 years old your coolant is ready to be replaced.

Differentials, transfer case, and Allison Tranny fluid/filter changes are great ideas too.

I'll jump on my personal soap box now: FLUSH YOUR BRAKE LINES :C

I don't know about your '13 truck, but the '99-'07 GM trucks were notorious for badly corroded brake lines that would suddenly rupture. You can't do much about exterior corrosion, but flushing the lines keeps moisture out of the inside and will prevent internal corrosion.

On my old '04 2500HD I realized at about 60K miles I'd never flushed the lines. I used a little Motive Products Power Brake Bleeder to flush them and I could not believe the difference in braking. As fluid ages it gets contaminated and does not compress as well which requires more pedal pressure. After flushing the system I was amazed at how little brake pressure it took to stop the truck. :E

KJ