90 XJ Brake woes-Proportioning valve?

Hi guys! got a problem maybe I can get a little help wiht. Here goes.
My brakes were really squishy and weak. Upon inspection noticed my rotors were trashed, pads were cracked, and the bleederes frozen beyond salvage. I went all new calipers rotors and pads.
Now its worse, even after bleeding. pedal all the way to the floor. Pumps up but bleeds off. I'm thinking gotta be the master cylinder right? Not really.
Put on a new one, same thing. Bled and re-bled. No dice.:wow:
I'm thinking its gotta be the check valve in the proportioning valve. Are these even available anymore? Has anyone rebuilt one and is there a kit?
I took it apart and its filled with crud. Im tinking thats gotta be ht prob.
Am I missing anything?
Yes I did bench bleed on the master cyclinder. Twice. I have never run into this and I've been working on cars and truck(all kinds for 30 years. help! Any ideas will be useful. Thanx!

You're saying that the proportioning valve check ball in the NEW master cylinder was filled with crud?

Even with that said I don't think that would cause the pressure to bleed off....sounds like maybe a leak in the booster or in a line somewhere? Or a fitting?

Sorry about the mix-up. The proportioning valve is filled with the crud. I may just clean it and put it back together and see if it works. unfortunately the system is airtight and the booster is good to. thats what has me so messed up. Thanks for the reply. This has me stumped.

How are you bleeding the system? Did you bench bleed the master cylinder before installing? I'd still guess that you have air in your system. The proportioning valve won't cause the pedal to go to the floor unless it's leaking or something. It is a good idea to clean it out though.

YamahaRick said:

Sorry about the mix-up. The proportioning valve is filled with the crud. I may just clean it and put it back together and see if it works. unfortunately the system is airtight and the booster is good to. thats what has me so messed up. Thanks for the reply. This has me stumped.

Click to expand...

Does the new master cylinder come with a new resivoir and prop valve? Or is it all seperate?

I don't know, I never bought one yet.

Blaine B. said:

Does the new master cylinder come with a new resivoir and prop valve? Or is it all seperate?

I don't know, I never bought one yet.

Click to expand...

WEll I got the old one and its all cast in one piece so the reservoir is all one piece. I looked at one however from a grand cherokee to see if it would fit and it also comes with the reservoir(plastic style) already attached so its ready to go.
The proportioning valve comes separate and is a dealer only thing and quite expensive. Junkyard is the way to go if you need one.
I talked to a couple diehard Jeep mechanics tho and they told me to a man that they never go bad. They do get cruddy tho and may need to be cleaned.
Hope this helps.

Hm, I should have took mine out and cleaned it before I bled after putting in new lines! D'oH!