rear breaks not working help!

[secondary-system]

my truck isn't stoping like its suppose to so i bled the breaks thinking it could have had air in the lines but it didn't so i did a test on a dirt road by going 10mph then slamming on the breaks. my result was only the front were making skid marks. also the break peddle has to be almost to the floor to stop good. you guys have any idea what could be the problem?

 

[KidVermicious]

LSPV. Make sure the LSPV is hooked up and at the right angle, then bleed all the lines starting with the LSPV then in order of distance from the cylinder.

 

[secondary-system]

LSPV. Make sure the LSPV is hooked up and at the right angle, then bleed all the lines starting with the LSPV then in order of distance from the cylinder.

i think i found the lspv its just over the passenger tire in the rear of the car. but i took the driver side drum off to see if it as moving at all and its not. i bled what i think is the lspv and the left drum break moved vary slight but not enough to do anything so i thought it would get better if i bled the rear and more air came out but then it didn't even move any more so i did every break and theres no air in the system at all. the breaks are still soft and the front is still working good.

 

[wshiverick]

maybe check the master cyl? or might have a leak somewhere else. Or you still have some air in there.

 

[secondary-system]

so i checked the master cylinders and there fine i re bleed everything but. theres no air in the lines up to the LSPV but after that the lines that go to the drums all I'm getting is non stop air and vary small amounts of the oil. think the lspv took a shit? thats my only guess o and i had a vacuum pump on hand and used that and I'm still getting the same results as by just pumping the breaks. i also had to adjust the drum pads.