Noticed the other day that PS fluid was dripping down from the middle of the pump. So I decided to replace it, and I have a few questions.

Now, the replacement pump came with a little parts baggie. Inside this is a nut, bolt, large washer and tiny O-ring. I'm assuming this is for what I've been reading about on here, involving pulling the PS pump gear and replacing the o-ring inside ?

Why would a new part come with this ? Just in case the O-ring that comes with it fails ? That doesn't make a lot of sense.

Also, I was looking at how the PS pump drive lines up with the vacuum pump. Inside the vacuum pump is a cross with a slot in it, the drive on the PS pump fits into this....now, lining the hole on the vacuum pump where the PS pump drive goes is a large round seal. The new PS pump didn't come with one of these, should I replace it with another one from Cummins while they are separated ? I mean, was the dripping PS fluid a result of this seal failing, or of a seal inside the PS pump failing ? The seal in question does look like it's in good shape. I've read before that there is a weep hole on the PS pump to let you know when it's going out, but I don't see one on this pump's exterior.

When I set the new PS pump on top of the vacuum pump, it's impossible to see if the cross with the slot and the drive on the PS pump are lined up properly. Do you just eyeball this ?

Also, the PS pump doesn't go on all the way, it sits on it's four studs a little "high" on the vacuum pump. It looks as if the nuts that you tighten down on the studs press the two pumps together. Is there a special way to do this ?

Finally, I think I twisted the oil line to the vacuum pump. Any idea what the PN is for this ?

 

I just went threw this mess. It was easier for me to remove the spacer that is between the PS pump and vacuum, to line up those tabs for the drive. Yes eye ball it. When you install the pump to the spacer you can see the seal ,how good or bad it fits around the pump shaft. It also allows you easier access to tighten the four bolts on the pump while its off. To my knowledge it seals motor oil in where those tabs connect to the slots. I did not replace mine only because I was in a hurry, however it doesn't leak. The pump I bought was from Advanced Auto and it didn't even come with the bolts to hold the reservoir on, fitting for the pressure hose, or the cap. Also be EXTREAMLY careful not to damage the steel return line on the steering box, I could not find one and had to use a three inch long, strait universal pipe, and bend it my self. I have 4 different tools for bending small pipe and had to still do with my hands, three inches is to short for the tools.

Good luck

 

the small oring is to go on the pressure line for reassembly..i think the big one is for if you buy a pump without the resevoir...they offer them that way also reuse yours on the new pump body...as far as the slots you have to eye it but it should slip together by hand do not use the bolts to pull it together...have to reuse the studs out of the old one...the seal inside the vacuum pump housing is used to keep the engine oil from leaking ..if it is good no need to replace but i smoothed some grease around it to help keep it soft and lube it also..as far as the oil line mine is braided and i dont know the part # sorry but a cpl weeks ago there was a used one from a parted truck on ebay for about $10.00 and didnt sell so thats the cheapest way to go..also slip the pressure line in by hand..i tightened mine with the nut and i think burred the inside as it tears the oring when i install it so have to remove and try to fix..hope this helps...by the way new gaskets are available for vacumm pump to housing mount for about $5.00 from most truck places hope this helps some

 

There is no way I see to fit the two pumps together other than to tighten the nuts on the bolts and press them together. Should I return the PS pump and try to find another ?

 

It sounds like you may have a non-intercooled PS pump.

 

It looks identical to the PS pump that was on there before. Atsco part # 7121

How do the two pumps differ from one another ? Maybe there is a pic on here somewhere of them side by side ?

Or perhaps descriptions of how the two pumps differ, or parts numbers ? I'm groping in the dark here.

 

anyone at all ?

 

Mmmkay, here we go. I finagled a camera finally, and the picture is the old pump and the new one side by side. They look totally identical to me, but is there some feature that I'm missing that differentiates the non-IC PS pump from the IC one ? The old pump is on the left, the new one (with the bolts from the old one on it) is on the right.

Now, what would cause the new PS pump to not just slip right on to the vacuum pump ? I went ahead and picked up a seal kit from Cummins NW last night for $10, the parts guy laughed and said that Dodge charges like over $100 for the same exact thing. I'll use the big vacuum pump gasket and the O-ring in between the two pumps from the kit.. Maybe with the new O-ring the pumps will match up better, who knows.

Thanks for the tips. Checked Ebay, might have found an oil line. Checked the classifieds on here, too, there was a guy parting out a 92, maybe he still has this.

 

Well, you have the right pump. I can't figure why it won't slide in there. Do you have the vacuum pump off the truck? Try taking off to make getting them together easier.

 

Yes, it's off the truck. I'm going to try Jer12377's suggestion of taking the spacer out first to get a better look at the PS pump drive lining up with the slot inside the vacuum pump.

 

The only way to get this PS pump the last 1/4" on to the vac pump is to tighten the nuts.

Believe me, I don't want to ruin a $400 vacuum pump.

It's the part of the housing circled here that is like a millimeter too large in diameter to fit into the hole in the vac pump on it's own.

So, I made absolutely sure that the slot was lined up with the PS pump drive, and tightened the nuts in careful stages. When I could feel the pump drive line up with the cross by turning the gear a tiny bit, I stopped tightening until the drive slid into the slot and I could feel the vac pump turning the PS pump.

Took it back apart for the photos here, and to make absolutely sure that tightening this down wasn't damaging anything. The right and middle photos are of the PS drive and the slot it fits to after pulling the two pumps back apart post tightening.

I just don't see any other way to get it on there.

Tried putting it on the motor, and starting it up. Burps power steering fluid out of what I am guessing is the cap...it's hard to tell exactly...and drips everywhere. The steering wheel is extremely stiff, so I didn't mess with that too much.

I guess you have to jack the whole front end up to bleed air out by turning the wheels back and forth, right ?

It's off the motor again and the two pumps are apart, pending further ideas from you guys. Like I said, I really really do not want to ruin a $400 vac pump...

 

Put it together carefully again and bleed it with the wheels off the ground.

 

I haven't jacked this particular truck up before. I do have a small floor jack, but seeing as the 5.9l Cummins is so heavy, where is the best spot to lift the entire front end up ? The crossmember ?

 

Probably going to have to do it one side at a time and put it on jackstands if you have a puny jack. If your jack has the guts then the crossmember would be the best spot.

 

I'll have a look at the floor jack and see what it's rated for. It is a hydraulic one, but it's not even three feet long.

What is the safest spot on these to go side-by-side ? I know it sounds like a dumb question, but I've never jacked up a truck with a 1200+ pound engine before...

Another option might be to get ahold of a vacuum pump somewhere, suck out the air from the system that way ?