Jim Roth

Started my 2016 2500HD and power steering was locked and the brake pedal was rock hard. Have taken to dealer and reported it before, as usual they could find nothing. Is it normal for the brake pedal to be rock hard when hill assist is on also? My major concern is to have that happen when I am towing my camper.

Suburban Dude

It sounds like a problem with your power steering pump and associated hydraulic power brake assist. On 3/4 ton models the power steering pump supplies hydraulic pressure to the rod of your power brakes. If the pump fails, you lose both your power brakes and your power steering, How’s that for a safety system. For some reason your power steering pump stopped suppling pressure. Check your fluid level in the power steering reservoir. Is the power steering pump pulley turning OK.? Are there leaks in high pressure or return lines to the pump? Is there noise from the pump. This should all be on warranty, correct? Hill assist, I can’t help you on.

Suburban Dude

This truck might have AHA, (active hydraulic assist), code NV8.If it does, there are some major electronics associated with it. Maybe find another dealer to look at it.

Jim Roth

Had truck towed to dealer. They called this afternoon and told me they couldn't turn the wheel either, 15 minutes later they drove it like nothing wrong. End result was they have to replace the power steering booster pump. Your reply basically is right on and I do agree with your comment regarding the safety system connecting the brakes into the power steering hydraulic system. Thank you for the insight into this truck, the dealer said this is very "UNCOMMON" with 2016 2500 HD'S. I would put more faith in your diagnosis than them so thank you again.