I have changed all the brakes, new linings , new drums , 2 new wheels cyls , 2 recon wheels cyls , recon master cyl.

Bled the fliud till it's clear .

Pedal seems fine when the truck is stationary , and under gentle braking , there is gentle retarding of speed.

BUT ! if I brake harder , the rate of deceleration is not much changed. The pedal will go down another inch and the rate of slowing down seems less.

It's kinda scary to drive , and I NEED to fix it in the next 2 days as I'm off on a 1000k trip.

I;m guessing it's a master cyl issue , but need your thoughts please. What might I have done wrong , I followed the shop manual proceedure. (original M/C for the truck.)