This is my 86 4runner which has a stock suspension. My brakes were hard so I replaced my booster. The good news is that seemed to have helped. But while I bled the brakes I noticed the rears were dry. The fronts were fine. I traced the issue back to the LSPV.

The two brake lines coming from the front are wet. Brake fluid comes out of the bleeder valve at the botom when you bleed it. But the outlet hose that goes to the flexible hose which then goes to the brake line over the axle is dry. Is there an adjustment I can do, or is it bad? In the pic, the line that is dry is the hook shaped one.

http://www.flickr.com/photos/29711249@N08/5659658988/
http://www.flickr.com/photos/29711249@N08/5659087063/

 

Try loosen the other side of the arm and move it up and down...see if that help. Maybe the valve is stuck. If that doesn't work, replace it.