New Proportioning Valve Leaking

[MattPSU]

I installed a new master cylinder, booster & proportioning valve a few months ago. I was able to bench bleed the master cylinder, got everything installed and bled the lines with no problem. Everything was fine for 6-8 weeks when all of a sudden, the prop valve started leaking heavily out the front and I lost 90% of my brakes. Fortunately, I was in my driveway and I was able to get the truck into the garage. Pirate Jack, the company I purchased everything through, sent me a new prop valve which I installed. Everything was OK for a couple weeks, and it starting to leak out the front again. After driving it some, I come back and the rubber boot is slowly dripping fluid.

I picked up another prop valve from another company (it looked exactly the same and the packaging was the same as well) and after a couple weeks, the same issue started. Slowly leaking out the front under the boot.

When the boot is off, and the brakes are pressed, the pin on the front of the valve pushes out and fluid leaks from there. Do I have another bad valve? Is there a pressure issue? Any suggestions on how to fix this?

Thanks in advance - Matt

Could it be a pressure