so lets go back one year.... ps pump leaked for 1 mo. at hydroboost fitting. let it run low for too long and ruined ps pump. "friend" who was ford mech. replaced pump and fixed leak at hydorboost. All was well after fix BUT at that time I had no "return" on steering. He said he'd look at it later. regained steering and brake control but just dealt with "return" issue. I had to steer, physically, out of turns. Wheels wouldn't straighten out themselves. after 3 mo. ps pump slowly went out again and i was back to gassing to turn and gassing to brake!!! Of course he would "get to it soon" and I must "have gotten bad pump". Finally this weekend i got new pump and said I'd do it myself. (I like wood not trucks!!!) Then got on forum and read about flushing system but that did not correct problem. Changed pump and pully but in the end I have the same results... no return steering. Brakes are back and can turn with fingers but will turn 360's unless i straighten out wheel manually. Have checked front suspension and 4x4 and u-joints and all are good. Thought I'd try flushing system again but with same results as before pump was changed... no flow during flushing while turning wheel L or R or while depressing brake pedal but "burst" of flow when pedal came up!! Actually noticed with some experimentation that fluid would flow back into system with turns of wheel and deprssion of pedal and would only flow out when pedal returned. Does this seem backward or what? Any ideas as to possible cause are greatly appreciated. I'm afraid this pump will die just as the first one did because of the underlying problem. Much thanks to all with replies!!! sorry.....

2005 f350 6.0 dually diesel 4x4!!!
stock but cat mysteriously disappeared with egr!!!

 

really? c'mon i couldn't have stumped all you guys!! anyone?

 

Just a shot in the dark, but maybe pull the fitting he replaced if he used teflon tape, maybe it is too close to the end and blocking flow. Maybe a return line could be deteriorating on the inside and blocking return flow.

 

Same problem but no "happy finish"

https://www.ford-trucks.com/forums/1...to-center.html

Looks like the consensus was front u-joints or steering box. I was looking for a post talking about a "spool valve" in the steering box but I couldn't find it. May have been another forum.

 

Thanks fellas. The fitting wasn't actually replaced on the hydroboost, just tightened. and there is no tape anywhere. Will look into pluged lines today. Also checked u-joints and they are tight, added some grease just to say I did. This is not a sporadic thing either- always 100% of the time??
The way hydroboost doesn't "flush" right makes me want to look into that end but don't know much about it. Any experts out there wanna chime in?

 

 

I agree, it should wear and loosen up a bit right at center. Also, as you say the lack of flow when doing the flush procedure would make me think it related to the pump. Maybe I was wrong referring to it as a "spool" valve, but there is a valve (in the steering box if I remember right) that controls fluid flow to even out the assist and comes in to play on return to center. I'll look a little more.

 

ok but i was actually referring to the screw adjustment for the gear box which makes it tighter or looser. Perhaps we are saying the same thimg? Also I've read a bit about the p/s cooler and wondering if a blockage of some amount could cause probs with whole system? Hope to play with it tomorrow after work. Will keep on reading in the meantime!! Thanks for your time folks!

 

Here's a written description but the pictures are missing.

https://www.ford-trucks.com/forums/1...t-rebuild.html

 

so we've got tot table this issue for now cause there's much bigger probs all of a sudden!! Don't want to hijack my own thread so Ill start new one shortly. Truck is DEAD so PS probs took aa back seat!!!!