86overland

Yotard

The front and rear brakes are completely isolated systems that's why there are two different lines coming off of the master cylinder so deleting lspv isn't going to cause it. Sounds like you didn't bench bleed the new master cylinder.

86overland

thefishguy77

iTrader: (1)

I'm fighting rear brakes right now and it making sure your drums are adjusted. And getting all air out of the line. Once the bubbles have stopped flowing from that one go to the drivers rear and repeat. If you didn't touch the fronts don't worry about it as long as you never let the MC go dry. If so the do the same for the fronts. Then properly bleed them and you should be good.

Bleeding order.
LR
RR
RF
LF
LSPV

NYHumpinUtah

iTrader: (1)

Could be a bad master cylinder, did you try removing one of the lines near the MC and push the pedal to see if fluid comes out?

wyoming9

iTrader: (1)

What did you do with the lines from the LSPV ??

It can be one of two things

Bad rebuild

kinked or dirt in the brake lines

Enough mud in the bleeder valves fluid can`t push through . that should be easy to see

86overland

muddpigg

iTrader: (1)

what did you do at the T junction behind the front passenger tire? The front and rear circuit on the 4wd ARE connected. Any poodles of brake fluid on ground under the truck?

akwheeler

Like mudpigg said, look for puddles and Wyoming mentioned plugged bleeders, I've seen it often. Pull one all the way out and make sure it is clear, I clean them out with a small drill bit then blow them out and put them back. if that works for one corner work your way around as you bleed.

86overland

akwheeler

If you bench bled it then you got fluid to move, so don't be random about breaking lines apart checking for fluid. systematically move farther and farther from the master cylinder until you stop getting fluid. then look for the blockage just upstream.
If you got fluid to move when you bench bled the master cylinder and you don't have any leaks either your pedal isn't moving the master cylinder or you have a blockage in both lines, or you are doing something wrong. try filling the master cylinder, leave the cap off, open all your bleeders and wait. see if the level goes down in the master cylinder.