brake bleeding problems

[Orange70chevy]

Was trying to bleed my brakes today but no luck on the rear breaks. At first I was getting air out of the lines and the fluid in the master cylinder would go down but then it just stopped. I'm getting no air no fluid and the fluid is not going down anymore in the master cylinder. What am I doing wrong here?

[cdowns]

a most common problem from not having the proppotioning valve clamped like it says in the manual to properly bleed brakes

[Orange70chevy]

Ok what do you mean by clamped

[Orange70chevy]

Ok. What do you mean by clamped

[cdowns]

Originally Posted by Orange70chevy

Ok. What do you mean by clamped

read the service manual it has detailed instructions

[El Dorado Jim]

haven't heard of clamped either

[kwmech]

tighten all the bleeders, turn on the ign, the brake light should be on with the parking brake released. Slam the brake pedal with your foot a couple of times till the lamp goes out. Resume bleeding the brakes. This should recenter the combo valve.

[snipescastle2]

I know that some of those combination valves have bleeder screws, would that accomplish the same thing? just curious....I've never heard of having to have it "Clamped" either, just bench bled the master cylinder then continued to bleed as usual.
Ben

[geezer#99]

GM had an angled (L shaped) tool that bolted on to the prop valve and was designed to hold in the reset button that is behind the black cap at the front of the prop valve.
That's what 'clamped' means!

There's a pic of a couple styles in post #7 here.
http://www.fullsizechevy.com/forum/g...-problems.html

[Vinceg]

I ran into this problem while bleeding brakes on my daughters truck. I may be wrong someone might have a better understanding of the prop valve and its purpose. If the person pumping the break pushes two fast the prop valve will push closed the line to the rear or front brakes which ever is being bled. This is a safety feature to prevent loosing your fluid on a line or cylinder failure. To get it to reset or back into the neutral position I had to close the blenders on the side that the valve had closed.(in your case the rear) then crack the bleeds on the front. Have the person apply the breaks. It took a couple of times before the piston popped back to neutral. It is a pain. I hope this makes sence.

[Orange70chevy]

Well I figured out my problem my rear brake hose is collapsing. Got fluid up to it but not after it.

[swamp rat]

Originally Posted by Orange70chevy

Well I figured out my problem my rear brake hose is collapsing. Got fluid up to it but not after it.

40 year old hoses can do that.. Glad ya figured it out.