Combination value help

[lutronjim]

I have several post of my front disk brake problem. I have replaced booster and master cylinder to date and problem is back.

The front disk brakes will hang at about 25% after hard stop. Brakes will release after quick tap of petal.

I have a fiend who builds street rods come by to help. After going through all the scenarios we could think of, we loosened the master so we could tell when pushing the petal just got to the booster or when it got to the master cylinder.
We determined that it took a tap to the master to release the brakes.

He looked at the end of the valve where the pin comes out and stated that it didn't look right. He had me lock up the brakes and he loosened the nut on the end of the valve - brakes released. Repeated 2 more times.

So now I need to buy a new combination valve. There are no markings on my valve. I see disk/drum valves labeled PV-2, PV2-B, PV2-C, and a host of others not labeled.

Mine is 2 in/2 out and looks like most GM valves - see picture. I would very much like to get the same physical size and thread size. I am a professional at kinking lines and have to have many many tries to make a good flair.

The current valve came in 6 lug front disk brake kit. I have since lost name of vendor who did his own machining. He stated he used Raybestos parts.

Any help would be appreciated.

[geezer#99]

Sounds like a collapsed brake hose.
Have you replaced them?

[lutronjim]

How would unscrewing the metering valve nut release a clogged hose?
I don't think its hose since both front wheels release at the same time.

[geezer#99]

Exactly which valve nut?
Both front wheels are teed togethor so might release togethor.

[mongocanfly]

Is this the pin your referring to?
POL should have what you need...https://www.performanceonline.com/un...-valves-parts/
Be sure to get the centering tool as well for bleeding the system

[lutronjim]

If you look at the arrow supplied picture from Mongocanfly pointing at the pin, there is a nut surronding the pin that released the brakes - maybe 11mm.

I found and ordered a combination value from Wilwood at Summit that I think will work - 2 in and 2 out.

Wilwood Brake Proportioning Valves 260-11322

[geezer#99]

Is the small line at the front of your prop valve for the front brakes?

[lutronjim]

yes

I have a full plate next week and will try to install later and will update.

[lutronjim]

Got time to work on today.

Installed a Wilwood disk/drum combination valve.
Slight rain in area - stood on brakes and locked front wheels - let off petal and coasted away. Repeated this 6 times so I think I'm OK.