Originally Posted by jkaftan
Called some brake specialists here in town and they are suggesting I replace the hoses between the Hydro-boost and the power steering pump. He used the term scalloping in the hose. He said that it is not likely the rubber lines attached to the caliper because the wheel releases when I turn off the engine. He said start with those hoses and then go for the Hydro-boost and or the power steering pump.
I noticed that I could not turn the wheel when the rig was at a stand still. I could but I had to put all I had into it. Anyway it seems to be either the power steering pump, hydro-boost or the hoses in between.
I did see a post on a P30 forum where a guy with similar symptoms had the brake light switch interfering with the brake pedal being about to return all the way. After replacing all of these parts his fix was to adjust that switch so that the pedal could fully disengage. Talk about pulling your hair out.
I am grateful that I do not appear to have the Auto Brake. I do have the big honkin lever next to my seat that seems to lock me in hard. Is that just a clamp on the drive shaft?
Oh and this is a gas motor Mayco.
I believe the hoses are way too large for this type of problem. Also shutting off the engine wouldn't open up the hose. The PS pump only provides oil under pressure, the hydro-boost has the control valves, I believe you have a tired valve. Unless the brake light switch was changed recently it is not likely the problem. If the linkage is binding due to corrosion it could be a problem. Reach down and pull the pedal up, if it moves check the linkage. If it returns to the stop on it's own go back to the hydro-boost.
This is a 31 year old truck, you cannot spin the steering wheel at idle like a new Caddy, rev the engine a little and roll forward a little and it will turn with little effort.