help with rear brake issue 72 cheyenne

[zicc1835]

well i thought i had a booster issue because my brakes did not perform as good as my stepside with no booster. so i replaced that when i separated the master cylinder i saw some fluid come out the back i replaced the MC i tried to bleed the rear brakes by pumping and holding down nothing but some drips coming out ...i thought i would gravity bleed the rears nothing but drops. i took the line off the back of the valve(red circle )and open one rear bleeder at a time and got the fluid to squirt out both sides one at a time when i put air to it... so to me no kinks or flattened line either side or any where ....i bought a new proportioning valve still can't get rears to bleed ...i took that line(red circle) off the back of the new valve for the rear brakes pushed the peddle down no fluid comes out the back of the new valve. fronts bleed fine ....took it out for a ride and stomped on the peddle a few times no change ...im not getting any fluid thru the valve to the rear brakes????? I believe my rear brakes have not been engaging at all since i started driving it a few months ago.... so I'm a dummy with all new parts ...thanks for any help

[leddzepp]

Whenever I bleed a brake system on any vehicle I use a hand vacuum pump at every corner. A Mityvac, or a cheap harbor freight knock off works. I have never had an issue doing it this way.

[snipescastle2]

try topping off your master cylinder and crack open the bleeders at each rear wheel and let them "Gravity" Bleed. takes a while, but the fluid will flow out slowly and push the air along with it, you have to keep an eye on the master cylinder so it doesn't run dry, or you'll be bleeding a lot longer..... those speed bleeders might also be of some assistance as well.
Have a good one!
Ben

[geezer#99]

You need to push in and hold in place the button in the front of the prop valve. It's under that black rubber cap.
Then your rear brakes will bleed.

[cdowns]

I AM TRUELY AMAZAED AT THE NUMBER OF PEOPLE THAT DONT HAVE A SERVICE MANUAL TO READ THE PROPER WAY TO BLEED BRAKES and cant figure it out

[MARKDTN]

Is the rubber line at the rear original? Could be it is internally collapsed and not allowing fluid to pass. (edit)Never mind-re-read and you are having trouble up front.

I found one once (on a front) with a nail in it. PO had a leak apparently and just stuck a nail in it so no fluid would pass. Scary!

[zicc1835]

Originally Posted by geezer#99

You need to push in and hold in place the button in the front of the prop valve. It's under that black rubber cap.
Then your rear brakes will bleed.

Thanks much ....I'm gonna give that a try

[zicc1835]

Originally Posted by snipescastle2

try topping off your master cylinder and crack open the bleeders at each rear wheel and let them "Gravity" Bleed. takes a while, but the fluid will flow out slowly and push the air along with it, you have to keep an eye on the master cylinder so it doesn't run dry, or you'll be bleeding a lot longer..... those speed bleeders might also be of some assistance as well.
Have a good one!
Ben

Thanks Ben I will also give that a try again if all else fails....

[zicc1835]

Originally Posted by leddzepp

Whenever I bleed a brake system on any vehicle I use a hand vacuum pump at every corner. A Mityvac, or a cheap harbor freight knock off works. I have never had an issue doing it this way.

Will do again as a last resort I think and hope geezer99 is on to something if that fails I'm in on a vac pump thanks

[geezer#99]

Fails!!
Never!! LOL!!
Just remember, keep it held in. You can make an 'L' Bracket and bolt it to the prop valve or rig up a big set of channel locks to hold it in.

[zicc1835]

Originally Posted by geezer#99

Fails!!
Never!! LOL!!
Just remember, keep it held in. You can make an 'L' Bracket and bolt it to the prop valve or rig up a big set of channel locks to hold it in.

no failures here Im gonna need a small punch to push that button in... if you and i are on the same page.. this exercise will be like some of the ethnic jokes.... a 3 man bleeding team LOL ....all joking aside i appreciate the advice and will let you know how i make out tomorrow

[lifeinak]

Is your dash brake light on. If the valve is tripped you should have a light. I believe ccp and others makes an inexpensive tool, less than ten bucks, that screws in in place of the switch and holds the valve centered during bleeding. Good luck.

[geezer#99]

Go gentle on that button.
It only needs to go in about 1/8 inch.

[zicc1835]

Originally Posted by lifeinak

Is your dash brake light on. If the valve is tripped you should have a light. I believe ccp and others makes an inexpensive tool, less than ten bucks, that screws in in place of the switch and holds the valve centered during bleeding. Good luck.

thanks I'm gonna look for that tool

[zicc1835]

Originally Posted by geezer#99

Go gentle on that button.
It only needs to go in about 1/8 inch.

thanks thats good to know too..... ill rig up something

[zicc1835]

thanks to Geezer got them bled, made my own tool welded a screw to the C clamp ...LOL crude but it worked cut down on the helpers needed

[geezer#99]

Congrats!!
Nothin' like a little 'McGyverin'!!

[zicc1835]

Originally Posted by geezer#99

Congrats!!
Nothin' like a little 'McGyverin'!!