GM Guy - 7/1/2020 08:53

GM got cheap on these and didnt put a power steering cooler in the diesels, just what you want on a rig designed to tow and relies on PS fluid to run the brake booster...

There is a direct fit cooler from GM, so they know its a problem.

IMO its cooked seals in the hydroboost and PS pump from overheated fluid. My 06 brakes suck as well. I have a new cooler, but havent installed it yet, but to do it right really needs a new pump, booster, and re-seal the steering box as its leaking fluid too, so I cant tell you that it will help you at all.

Regardless, a fluid change with a good full synthetic PS fluid would do nothing but good, so I'd at least do that.