HELP! Installed Tom's Bronco Power Brake Conversion w/ Front Discs...

[bdfeenie]

...and I have no Brakes! system is fully bled, and when truck is running, the pedal goes dead to the floor. We can hear air coming from the booster rod where it goes into the booster itself (area with the rubber boot) when pumping the brakes. Could this be the vacuum leak causing this? We are at a loss. The vacuum setup everywhere else was untouched. We have the new proportioning valve installed as well.

Any help would be greatly appreciated!

Thanks in advance!

 

[mountainview68]

I had a buddy with the same problem and he had his calipers on upside down. Bleeder valves go on top of the caliper

 

[bdfeenie]

I believe that we did the same thing, and fixed it last night, but the problem still exists...

Now what?

 

[ken75ranger]

You need to isolate the problem a bit. How do the brakes work with the engine turned off? If the pedal is solid the problem is on the booster side. If the pedal is soft the problem is from the master cylinder to the brakes.

 

[Ethansdad73]

Dont the brakes need to blead in a certian order, just incase...

 

[BigO]

Just a couple of ideas, that are often the overlooked.

Did you fully "bench bleed" the master cylinder first?
Are the calipers mounted with the bleeder screw pointed up? (as mentioned above)
Did you start at the farthest wheel, and work your way to the closest? Right rear, left rear, right front, and finally left front?

 

[BlackHorse]

GM type disc conversions need clearance between the calipers and the steering knuckles. Look right over the top of the tire. Look straight down at the caliper. You need a good amount of space for the caliper to move. If it's hitting the knuckle remove it and grind the knuckle for clearance.

 

[bdfeenie]

knuckles were ground before we put it back together.

I found out like a dummy, we needed to Bench Bleed the master cylinder separate out of the truck...don't remember reading that in the instructions...

Evidently there is a ton of air behind the piston in the master cylinder, and around the ports.

At least it wasn't something major. Tom's was a big help!

Thanks for everyone's input!