Update. I caped the front lines and just add the rear. Pedal was harder and didn't go to the floor. So with that I put both lines back on (front& rear). The pedal fade to the floor as u pushed on it. I then after that swaped the calibers and put new pads on off a 97 Dana 60 I picked up tonight for a solid axle swap. Did the same thing after blessing them.

For the final thing for the night was hooking the vac gauge back up. It was pulling 45 and dropped to 20 when stepping on the brakes at an idle. If I pumped them I could take it to zero. If I stood on them it would drop and to 20 and build back up. This is where I'm at? Bad vacuum pump?

 

Wow, cool, is there a patron saint of brakes? (St. Bendix? )

You probably need the "zero loss" booster listed above (see 91 Dually's post #26).

 

It was fine till is sat for 3 weeks for a turbo rebuild then this.

 

I iPhone auto spell!

 

Doug, this happens immediately or after driving a while? I have an issue where the brakes are fine, but after driving a while (w/o using brakes) they will be extremely soft, push to the floor and will slowly build up after pumping a few times. I have just been making sure I tap the brakes occasionally while on the freeway to stop this from happening. Sounds like I may have a leak in a line somewhere? No trying to Hi-Jack

 

This happens as soon as I start. What I can't figure out is I drove it into the garage. Parked it to put a turbo rebuild and down pipe in. Now is seems to have long cranks to start the brakes when to carp. All from siting 4 weeks. If just getting really fustrated with it and almost ready to sell and be done with the obs and move to the sd side.

 

I understand your frustration but this can happen with any vehicle, hang in there. You seem to me to be a 'not give up' kind of person because of all the things you have done already!

Madpogue, that just to funny! LOL

 

I just can't keep dumping money into it. I'm going to see if I can find the vacuum receipt and get a new one under the warranty and try that.

 

This is strange and would point to the front brakes as the trouble.Are all lines in good shape for the front? how about the brake proportion,valve ? Perhaps you bumped into the brake lines a little to hard when working on the Turbo?

 

All the lines look good and there is no bubles in the ruber lines. No lose of fluid.

 

my 88 did the same thing. cap off the fronts, brakes went to the floor. cap off the front so only the rears were working, rock hard pedal.

new master washed out real good before bench bled and all the problems disappeared.

 

I did wash the new one out I just got. Still does it. Thinking about the hydroboost if I can find the parts I need.

 

How about the Proportioning valve on the master cylinder?

 

Hydroboost parts from Autozone:

Hydro Unit: p/n 52-7079 $120.99 plus $57 core
Pressure Hose 1: p/n 71442 $21.99
Pressure Hose 2: p/n 71416 $18.99

 

Brown does the unit come with the pin that push on the MC?