This could be bad for GM

Vacuum pumps wear out over time, just like anything mechanical does.

Had no idea they went back to using vacuum for power brakes. Thought the hydroboost system was the choice for Diesels. The old GM Diesel car engines used hydroboost for the brakes but had a vacuum pump for the A/C controls. Those always failed early, hydroboost always worked. Ford gas F-53 Class A chassis use hydroboost.

Twice the wifes 2016 chevy 1500 5.3 crew cab short beds brakes went away at idle while making a multi point turn around in a crowded parking lot.
Both times the engine was at idle. Both times I got it in neutral/park quickly and run the rpms up. Brakes came back.
Took it to one of my chevy dealers and complained. Mechanic says their seeing this a lot. Service mgr says he hadn't heard anything on the issue. :R

Jimnlin wrote: {...}
Took it to one of my chevy dealers and complained. Mechanic says their seeing this a lot. Service mgr says he hadn't heard anything on the issue. :R

Hmmm, ServMgr must be related to Brooks & Dunn: “Deny, Deny, Deny” :B

garyemunson wrote:
Thought the hydroboost system was the choice for Diesels.

Hydroboost is expensive and not a "perfect" solution either, especially since more and more vehicle are going EPAS (electric power assist steering).