Originally Posted by mick883
Little confused...why do you pump the brakes at the same time that you move the steering wheel from bump stop to bump stop? What does pumping the brakes do?
We don't have a vacuum all the time in these trucks (there is one between the intake and compressor UNTIL you let off the gas, then the boost goes out that way). So since the vacuum is small and unreliable, you need a way to run the brake booster. So you use the PS pump to boost the brakes. I'm guessing that there is a cylinder in there that is pushed by PS fluid and pushes brake fluid. By pushing it in and out you get the fluid left in there out and new in. I'm sure there's not much though.