Brakes 89 pickup 4x4
 

I have been through my brakes ,bled them and made sure all calipers are working. My problem started with a soft brake pedal. I assumed air in the lines,bled some air out of lines but now i am experiencing a different problem:When I press brake pedal it is firm but I get no braking action ,then a split second later the pedal gives and finally I have brakes.
I am thinking a bad master cylinder. Any ideas?

I'll go along with bad MC, but I'd like to know a couple of things: Do you get the same problem with the engine off? Have you checked the booster?

While bleeding the brakes I got a full brake pedal on the passenger rear temporarily and then that never came back. Other than that time I cannot get a full brake pedal( compared it to my 94 yota). It acts like some kind of bleed by in the system.
I haven.t checked the booster b/c I didnt think that would cause a problem unless engine were running.I will definitely check her out in the morning though.

look into the FSM, it has instructions on how to test for the booster.
My MC went bad and I could tell because the truck would start to move a when I was sitting at a light. It's an automatic, but the peddle would sink slowly to the floor. That's the sign of bad MC seals letting fluid pass through.

Bad MC was the culprit. when I pulled the reservoir I saw rust !.New MC and she is braking like new. Thanks for the input.