Hard brake pedal

On a 2000 GMC 2500 pick up when I reach a certain point turning right the brake pedal becomes hard and will not depress. Therefore the brakes won"t work. As I turn further or back they will work again. Any Ideas?

The brake system in your vehicle uses the power steering system to provide brake assist. It’s called hydro-boost. If there’s a problem with the power steering system, it effects the brakes.


I was not aware of that. I thought there was just the power assist master cylinder. What could cause such an odd situation? If the power steering fluid is good could there be a kink somewhere, or is this an indication that the power steering pump is going out? Any thoughts on where to start looking?

Power steering pump, hydro boost module, or steering rack. It’s a system, and something is not right. I’d start at the pump, since it seems to be failing to provide proper pressure.

I would suspect the steering gear.

Everything works fine until the steering wheel is at certain position. If the seals in the steering gear are worn at a cerain point where the power steering fluid is able to bypass the seals, pressure is lost to both the power steering system and the hydro-boost system.