Another Brake Problem Thread

[68 P.O.S.]

So, I just did a complete brake job on my truck and I cannot get a decent pedal. I'm in a time crunch since I need the truck for work in the morning, so I'm searching for threads as well. Anyway, for the front I replaced the rotors, calipers, pads, and hoses. For the rear I replaced the drums, shoes, all hardware, and the hose as well. The brakes were gravity bled and I called it good. Got a great pedal right off the bat, then, as soon as I started the truck, it went away. Test drove it and pedal goes to the floor and the truck stops slowly. Replaced master cylinder, bled system, and same result. I've bled the system 3 times and no change. I get a nice high pedal each time, then it goes away when I start the truck. Any advice, except for "use the search", is greatly appreciated.

[68 P.O.S.]

Sorry, forgot to mention, the truck has factory power brakes

[70CHEVYBB]

calipers on upside down? did you adjust the rear brakes properly. you may need more the gravity bleeding.

[mechanicalman]

Originally Posted by 68 P.O.S.

So, I just did a complete brake job on my truck and I cannot get a decent pedal. I'm in a time crunch since I need the truck for work in the morning, so I'm searching for threads as well. Anyway, for the front I replaced the rotors, calipers, pads, and hoses. For the rear I replaced the drums, shoes, all hardware, and the hose as well. The brakes were gravity bled and I called it good. Got a great pedal right off the bat, then, as soon as I started the truck, it went away. Test drove it and pedal goes to the floor and the truck stops slowly. Replaced master cylinder, bled system, and same result. I've bled the system 3 times and no change. I get a nice high pedal each time, then it goes away when I start the truck. Any advice, except for "use the search", is greatly appreciated.

Let's go back in time. How were the brakes working before you did the brake job?

Did you do the brake job because the pads/linings were worn ONLY or did you have a malfunction OTHER than wear/normal maintenance?

The only thing different when you start the engine is the booster starts working.

If you remove the vacuum booster hose and plug it, will the pedal stay high or will it drop to the floor when you drive it?

[68 P.O.S.]

Originally Posted by 70CHEVYBB

calipers on upside down? did you adjust the rear brakes properly. you may need more the gravity bleeding.

Both are on correctly.

[68 P.O.S.]

Originally Posted by mechanicalman

Let's go back in time. How were the brakes working before you did the brake job?

Did you do the brake job because the pads/linings were worn ONLY or did you have a malfunction OTHER than wear/normal maintenance?

The only thing different when you start the engine is the booster starts working.

If you remove the vacuum booster hose and plug it, will the pedal stay high or will it drop to the floor when you drive it?

I bought the truck not too long ago and don't know the history of it so I decided to overhaul the brakes. The brakes were working fine before I started work on them. I'll check the booster.

[nzc10]

Did you bench bleed the master cylinder before you fitted to the booster? I have always bleed up my master cylinders before fitting you will still need to bleed up brakes , saves a lot of hassle and time

[cdowns]

IT HELPS IF YOU HAVE A FACTORY SERVICE MANUAL AND read UP ON THE PROPER WAY TO BLEED THE BRAKES AND YOU'LL B GOOD TO GO