85 blazer, proportion valve

I have a 85 s10 blazer (2wd). Just a few days ago the proportioning valve started leaking brake fluid out of the small hole in the bottom of it every time I brake. Enough got out it took all the paint off my inner wheel well (everything under the car and hood was previously painted).

Ive been to a few shops, used car parts shops, and called the dealership. No ones got proportioning valves. Any idea on where I can get a replacement or why it does this? Brake fluid just shoots right out of the small hole (seems to be plugged) in the bottom of the valve.

Theres a bad o-ring in there. Just go to the junker. Blazers are usually plentiful, and i believe that they used the same prop. valve for many years, so you shouldnt have trouble finding one.