Umm, how do you not know, by now, what a Hydroboost is? Anyway, that's what we have. Virtually any diesel will utilize a hydroboost power steering/brake system ( "big" trucks with air brakes aside). In a gas engine, vacuum is generated by the engine, and can be used by the brake booster to provide power braking assist. So, the power steering system only has to do that job.
Diesel engines don't generate any significant reliable vacuum, so nothing there to operate a typical brake booster. (Gas engines with "big" / "lumpy" cams with lots of valve overlap can have this problem as well.)
Instead, diesels will piggyback off the power steering system, to provide power to a hydraulic brake booster instead. Normally, if the system and all its components are well matched, this works fine.
Except, that is not the case on the SuperDuty

If you do some Google searching, beyond the fuddy-duddy stick-in-the-mud confines of this forum, you will find many references to the notorious well known inadequacy of the SuperDuty Hydroboost system. Specifically, much like in many other Ford vehicles, the power steering pump SUCKS. Even when new, they whine and moan. Even in lighter duty applications, such as cars or Rangers, the pumps are barely adequate. They are simply an inferior design. In the case of the diesel SuperDuty, they can't move enough fluid volume to properly feed both the brake booster and the steering gear. In fact, they often can't even manage to provide good steering effort alone.

A number of people have done a Saginaw pump conversion, which replaces the power steering pump with a higher flowing, quieter, longer lasting GM Saginaw style pump. The problem is a bolt-in minimal hassle kit is expensive. Due to some issues with pump body clearance ( on the mounting bracket) and especially with pulley alignment, piecing together a DIY home built setup is challenging.
I intend to do some more research on this, and go this route when I do my major truck overhaul in the summer. I just hope my failing stock pump doesn't lock up before then. At this point, it feels like its barely moving any fluid at all. I hate the idea of having to waste money on a "stock" style replacement now, only to throw it out later.

 

 

That's HILARIOUS!!!!

 

Not what I said...

I am surprised (if) they are in series and asked if it uses a power beyond, using hydraulic systems lingo.

Small google-hit discussion that describes it, compared to priority valve.

It sounds like a priority valve setup for brakes, or direct series. Which one, I don't know.

 

 

It's all good

I do get irritated sometimes- recently even- but not very often and not for small things.

Besides, he's often helpful and I don't mind a bit of ribbing- especially if I post something dumb or incomplete because I was rushing.

I hoped someone who was familiar with hydraulics would pick up on that right away and tell me which way it is.

Thanks

 

All my tires were running low. Aired them up and now the EX runs as intended. Thanks for the reminder to look for basic stuff first