77 C10 power brake conversion issues

[77c10]

I recently installed a brake booster and new master cylinder on my truck. It came with manual brakes. I bench bled the master cylinder and installed it on the truck. My issue is the brake pedal goes all the way to the floor now and will not build any pressure. I double checked myself and the pushrod from the booster is attached to the pedal. Is there a difference in a non power pedal and power brake pedal? I plan to take the top off the master cylinder tonight and have my son pump the brakes to see if it is doing anything. Any help or ideas that anyone could give would be greatly appreciated.

[tasian]

have you bled the brakes since you finished the install? if not theres probably just air in the lines still sometimes it takes a while to get it all out you could also try adjusting the pushrod at the pedal but try bleeding them first

[77c10]

I have not bled them since the install because it does not seem to be building up any pressure. I will try to bleed them tonight and see what happens.

[tasian]

yeah you might wanna try to gravity feed them first if you have any problems pumping the brakes

[77c10]

I have decided that I have a bad booster. I removed the lid to the master cylinder and had my son pump the brakes and did not see anything going on. I took it off and bench bled it again and it worked fine. I think I will buy a new booster this time instead of getting one second hand.

[N2TRUX]

Originally Posted by 77c10

.... I think I will buy a new booster this time instead of getting one second hand.

Good idea. If that doesn't do it, try gravity or pressure bleed the system as suggested.

[cdowns]

did you adjust the master cylinder pushrod after installing it into the booster?