brakes 79 bronco

[bsbrawner]

As some of u can see i do all my own work ,having brake probs,push pedal to floor and is stiff replaced everything accept proportioner valve any suggestions

[schmidlkofer]

do they go to the floor while driving? are the rotors toast? how about the master cylindar failing although its new.....hmmmm do you have power breaks on it.

[shawns 64 F100]

was this problem before you replaced the brake booster and master cylinder? sometimes the shaft inside will bind up causing it to not move so well.

[bsbrawner]

rotors all good,when brakes are bled it moves plenty of fluid,pedal stays up while driving,brakes worked poor before i started upgrading,what about vaccum psi what should that be,i only use lines for brakes,tranny,dist,both of pcv valves go into manifold,could i be loosing to much vaccum that way

[Glass]

rotors all good,when brakes are bled it moves plenty of fluid,pedal stays up while driving,brakes worked poor before i started upgrading,what about vaccum psi what should that be,i only use lines for brakes,tranny,dist,both of pcv valves go into manifold,could i be loosing to much vaccum that way

I run 1 PCV, and one breather off of my valve covers. What size tires are you running? Have you pulled the rear drums to look in there? Do you loose brake fluid? is there any change in the way the brakes act if you remove vacuum from the brake booster and cap it off?

[shawns 64 F100]

as long as you dont have a leak the vaccuum should be fine. unless you have a huge cam thats taking it all away. I would check pedal travel without the vac line connected then again with it connected and see if you even have any boost, if not you need a booster, also check the check valve at the booster where the line is connected to the booster

[Hypoid]

Does the "brake" light on the dash work? Does it come on?

If the answers are (1)yes and (2)no, leave the prop. valve alone.

[bsbrawner]

39.5 tires i have been through rear drms the rear will lock up before the front,same with my 31's,have not tried capping booster,new booster do not hear any leaks through booster.brake light in dash comes on after starting but goes off.feels like Im not getting help from booster

[fox]

Make sure you aren't overadjusting the rear drums. I did that once and it sounds like what the bronco was doing. I also check the pushrod length going into the back of the master cylinder.

[Hypoid]

Have you replaced the flexible brake lines? Are they DOT approved? That's more a shot in the dark than anything. I've read about obscure problems related to the flexible lines.

The PCV thing has me puzzled. Like John (Glass) said, you should have one vacuum line from the intake to the valve cover to draw off the crankcase vapors. The hole in the other valve cover is to let fresh air in.

The hose to the distributor should be ported vacuum at the carb, meaning no vacuum at idle.

The hose to the tranny and the hose to the booster are the only other hoses that draw from the intake...right?

Based on what you wrote, the proportioning valve is not stuck.

When you ordered the master, what application did you give the auto parts, a '79 Bronco?

[shawns 64 F100]

I almost forgot and fox already posted, did you check the pushrod length when you installed the new master and booster?