More brake problems

[CountryBoy704]

So I just replaced my brake master cylinder and booster today, bled the crap out of the system and getting no bubbles out at the wheels. The pedal is still soft like butter, if I crank the truck up the pressure from the booster sucks the pedal all the way to the floor. I'm guessing this means I didn't get the master bled well enough? Just wanted to get some opinions before I rip it back off tomorrow.
Thanks

 

[adsm08]

Sounds like a booster issue. You may not have it bled right, but it sounds like there is a booster issue of some sort.

You can bleed the the master in the truck. The process is similar to a regular brake bleeding, except you crack open the fittings on the master while the pedal is down.

 

[CountryBoy704]

is there a way to test the booster? it's brand new OEM. I figured it just sucked it down because the pedal has absolutely zero pressure, I can floor it with hardly more than the weight of my foot.
Thanks for the tip on the master! I was all set to pull it out and retry the bench bleed.

 

[freedom5]

Are you sure you got a new master for power brakes? It's a bit different than the regular one. Also there is an adjustment that can be made on the rod that comes out of the booster. The specs call for .995 inch (that's about as close to an inch as you can get). This adjustment basically adjusts the pedal travel. Also make sure the rear shoes are adjusted. They are supposed to be self adjusting when you apply the brakes backing up but that doesn't always happen. I also went through three master cylinders before I got a good one even though I bought supposedly new not re-man. Good Luck.

Freedom5

 

[CountryBoy704]

Yeah I almost bought the manual brake cylinder because it was a lot cheaper but realized why when I saw it, didn't check the booster throw I assumed it would be close enough to spec from the store? The pedal moves plenty of fluid when bleeding it just never builds up pressure. I'm going to go through and re-check and maybe replace some lines and whatnot this weekend.