Brake help PLZ!!!! loosing my mind..

[72 Madness]

Ok were do I start. Bought this 72 k5 4x4 truck a while back and just got it running. It didn't have a brake booster, master, or proportioning valve on it along with a list of other things. Got everything hooked up ( i think correct) and I'm having a couple of issues.

1st. Having a wooden brake pedal that doesn't seem to push down very much.

2nd after bleeding the brake lines for a thousand times I'm not getting any fluid to the back lines.

3rd the truck stops but not very well. Which I'm sure since the back brakes are not getting fluid.

Can someone please look at how I have the propotioning valve lines hooked up and tell me if I need to change them. I have looked all around the site but have not come across what I needed to know. I have seen them hooked up backwards and the way I hooked up mine. Which one is correct for a 72 k5 4x4? Any help would be GREAT!!!!!!!

[Burt4x4]

This is 1Ton K30 dual diaphram booster. It is opposit of 1/2 ton.
So if the booster you put in is a single = 1/2 ton booster then you are plumed correct. Your P-valve is after market and ??
Do you have rear disk?

[72 Madness]

My P valve came off of a 85 chevy van. I was told that it would work just fine. Now I'm wondering. I have disc front and drum back.

[Burt4x4]

It "looks" aftermarket. Like what you see at Summit. The one in my pic is what came frome factory so could be yer issue. Junkyard or parts house...

[72 Madness]

Not sure what did it but it they work now. I took off all of my lines and put a compressor to them. Then I change out my proportioning valve. Now we can stop. Sure does make things easy when you can stop.

[cleszkie]

Agree with Burt. That proportioning valve does not look like a stock unit. Stock units are cast iron. That one you show is milled out of aluminum, and looks a lot like the one I installed for my rear disc brake upgrade. That probably explains why the prop valve swap solved your problems.