4.3 Vortec 1989 Chevy s-10. Question Here. Give as much detail as possible. : I'm stumped...no brakes, no one can help....hard pedal before starting but when starting pedal goes to floor...replace items master cylinder, power booster. Used proportion valve. Bleed and bleed ...no avail...i guess to a master shop.

Did this problem just start all of a sudden, or right after one of the repairs you listed?

After repairs, after rigging have brakes at bottom of pedal.....use  nuts..shims some how longer pedal rod. Antilock....how to bypass switch....its. 1989 Chevy s-10 Tahoe..no  computer check for inspection.  can you help there.

Answer: If you are saying that you tried using nuts and shims to adjust the pedal, you need to put everything back to what it was before the problem and bleed brakes. You have air in the system somewhere. Pedal should be hard until you start the truck because no vacuum in system. You have air in the system.