I am trying to get my truck back to running condition and my brakes are being a pain in the ass. I have no emmissions or charcoal canister or anything like that. The only vacuum I have is the vac advance and the line with the check valve off the booster to the intake. Am I missing parts or what? I get a hard pedal if I push multiple times with the truck off and it firms up when I press multiple times with it running. I'm reading the booster would leave me with a firm pedal all the time, so maybe it's my master cylinder? I have bled the brakes for what I have found to be enough, but I don't know if it is or not, we're going to do it again. Can anyone help me?
Did you bleed the rear proportioning valve (attached do the long lever that goes to the rear axle)? If there is any air in that line the system will feel mushy. Toyota has a specific sequence for bleeding.
If the pedal is still firm to push after bleeding but the truck stops fine, then check your check valve leading to the brake booster, also check that same line for leaks(replace if needed) if you still dont find the problem with having stiff brakes your brake booster may be shot but thats rare to happen. Good luck and keep us posted