No brake pedal pressure?

MAYOBAMA

MEMBER
1979 FORD BRONCO

Recently my front brake calipers locked up on me while I was driving. I had the Bronco towed home and began fixing the problem. Long story short, I had to replace both front calipers, brake booster and master cylinder (leaking), proportioning valve (clogged so no fluid was going to the rear), rear wheel cylinders (leaking), all the flex hoses, and the shoes and pads. Now when I bleed the brakes on the truck with it not running, I get a good stream of fluid from all the bleeder valves and a good pedal. But when I crank the truck the brake pedal goes straight to the floor. I tried bleeding the brakes with the truck running but I still get good fluid from the bleeder valves but still no pedal. I bled the master cylinder both on the truck and off and neither has helped at all. Does anyone have any ideas of what is wrong?

2 Replies

BIG_JAY

MECHANIC
121 POSTS

Did u put a new or reman master cylinder? Are your rear brakes adjusted tight? Who is helping u bleed the brakes. The last question is because I used to have a kid that worked with me that never pushed the pedal hard enough and I would always get a spongy pedal. I also get about 4-5 bad reman masters a month and it will give you a bad pedal with the truck running. Please go over this guide to help us see what's going on.

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please go over this guide and get back to us.