Don Lindsey

The brake booster operates on vacuum. The vacuum is provided by a vacuum pump driven by the engine. The engine vacuum does not power the booster. I foind my faulty pump because I had brought the suburban in to diagnose a torque converter noise. The dealer told me it was a noisy vacuum pump, and normal noise from direct injection pump. I told them the brake vacuum pump is an internally engine oil lubricated part, and should be covered by warranty. All internally libricated parts are covered for 100k on the ‘15. They denied it. A few days later, sitting in a drive through, I got the hard pedal after a few quick brakings at low engine speed. The problem is that the vacuum pump isn’t providing enough vacuum to last at low engine speed. I replaced the pump ($100) and installed it myself. Went back to the dealer and pitched a fit. Escalated to GM directly, and told them about the pending recall, pending lawsuits, and TSB they issued. Eventually they offered me a $100 service credit good for parts and labor on my next visit.

Hey guys. I’ve had the same problem. no one has addressed their parking brake. Car stopped wheels not rolling. Pressing brake hard causes the creaking. I thought it was the caliper pins or the pad backing plates where they ride on the caliper mount. Removed and luned all moving parts on service brake. No improvement. It isnt the friction material because it happens when not moving. The other day a guy parked next to me in his suburban, doing the same thing. It made a louder creak when setting his PARKING brake. Eureka!! I pulled the calipers off, and removed the rotor. I lubricated the parking shoes backing plate, and all the retaining springs holding shoes together. That fixed it. Pressing the brake causes the rotor to flex just enough to cause the rotor to move the parking brake shoes. Good luck.