just had the same problem. One of the hose fittings went bad going to the power steering pump and it was leaking from the hydro boost as well. On top of that my steering box had a ton of play and it started getting dangerous so I replaced the steering box, Hydro boost,p/s pump, p/s lines, rebuilt the vacuum pump with the kit recommended by the other members, and that man is awesome answered all my tech questions while I was doing it on Sunday. May have been overkill on the replacement but at 215k miles I figure the other components to the system would need replacing soon anyways and didn't want double the work later.

 

He really does go above and beyond the call of business for his customers. I know it sounds stupid to spend $60 for somethin you could get for $15 from the dealer but with all things considered, a step by step video, the special tools needed no matter how simple they are, and the customer service no matter what day of the week it is, as far as I'm concerned it's money well spent. I never would have figured that rebuild out without that video no matter how long I worked on it and i would have spent hours shopping tryin to get the right sizes for those punches. He was a sponsor here for a while but didn't get enough business to make it worth his while and I'm still scratchin my head wonderin why. Maybe if enough of you mention DieselBombers to him we'll get him back. He's the kind of sponsor we look for on the site.

 

Ok, just finished replacing the the PS pump. Filled the reservoir with Mobil 1 ATF synthetic and cranked it up. Still no power steering, the brake pedal is hard as a rock, and the fluid is seeping out the top of the reservoir. I'm sure there's air in the system. On a good note, I no longer have the whirling sound that I had from the engine bay before, which I assumed was the PS pump going bad.

As for the replacement, getting it in and out was a real PITA, but I had some help from a friend and we managed. Aligning the teeth on the end of the pump shaft inside the vacuum pump while balancing on a step stool all the while unable to see what you're touching sucked.

Update - After a brief search, I found a thread with a decent write up on the cummins forum:

http://www.cumminsforum.com/forum/98...self-help.html

"ok heres the deal. lines need to be removed on the pump then there are four studs with nuts holding the pump onto the vacuum pump housing. use a 15mm socket to remove these nuts. the two nuts closest to the block are easiest removed from under the truck. ( It is much easier to do this when you detach your ecm wiring harness from the block). after that pull the pump out. be careful not to damage the oil seal. next is the hardest part. put the new pump in the vacuum housing. WARNING someone needs to manually turn the motor using a 23mm socket turning counter clockwise on the alternator nut. this will turn the vacuum pump. while the vacuum pump is turning you must match the splines on the p/s pump shaft with the female in the vacuum pump housing. the easiest way to see what i'm saying is to take a mirror and look into the housing. now when the pump matches up with the vacuum pump it will slide flush up against the housing. then, put the studs and nuts onto the new pump. reattach your lines ( the two rubber lines are both return lines so you don't need to know which is which). fill the pump. now i would suggest jacking the front end up, starting the truck and turning the wheel different ways. this will bleed the system of air, and leave the cap on the pump, it is vented. i turned the wheel without jacking the truck up and it snapped the shaft on one of the p/s pumps."
-posted by Dieselhead117

The stuff in bold was exactly what I was looking for. I had my wife sit in the cab after I jacked the front end up. With the motor runnin', I had her turn the wheel from full lock left to right back and forth slowly a few times while I watched the reservoir with the cap off. Lots of bubbles came out with plenty of fluid. Quite a mess to clean up later. I had her shut the motor down and the fluid level dropped significantly as the last few large bubbles escaped. I refilled the reservoir and reaccomplished the procedure with fewer bubbles. After a top off, I took my truck out and enjoyed driving it without the whirling sound of a failing PS pump. The brakes felt much better and the truck's steering was much smoother. Upon returning to the house, I found a small oil leak, which I can only presume must be the vacuum pump seal given the location of the drips. Apparently this is easy to damage during the reinstallation of the PS pump. If I have to do this again, I will take the PS pump and vacuum pump out as a unit, and reinstall them together, while replacing all the lines. I hear the steering box is a good thing to do at the same time.

 

The kit is $8 from Cummins. The one I got had no DVD or special tools. It did have a several page instruction sheet with pictures and I can't think of any special tools that I person would need even. A seal driver set would make it easier, but I just used a block of wood and some sockets.