Here is my problem: Tonight leaving the drive I had no power brakes. If I turn the wheel a little bit I get my power brakes back. Things I have noticed 1) weak power steering. 2) the steering wheel will jerk as if pushed buy the power steering usally to the left about 1/16 to 1/8th of a turn. when you correct for the left turn it will jerk to he right. Things I have replaced trying to corrcet this steering issue before the brakes acted up. Ball joints, tie rod ends, steering gear, power steering pump, and checked the axel u-joints which are good. I think my problem is in the hydro-brake booster. Is there a relief valve or presure valve that could be intermittently causing the power steering to change presure and give me the jerk in my wheel? Sometimes I have good steering power and others if the truck isnt moving you arent gonna trun the wheel. Something is bleeding the hydraulic presure. The jerk in the wheel often comes when I am just accellerating and comming off the brake. It never happens if I am on the brake. Today is the first I had issues with no power brakes, so makes me wonder since the steering issue was fine for months and the last few days it is back bad. Thanks for all your help!