Saginaw pump question.

[heviarti]

So, I have been stuck with a 1979 GMC. Among its foibles is a screwy power steering pump. It whines, it leaks, when you take a turn it feels like you are driving over sagebrush, and the inside of the reservoir is rusty. obviously the solution to this is to replace it, but what I don't have is $58. Enter the 1994 chevy parts truck my work bought. They are both saginaw 'teardrop' style pumps, though the rotation on the '94 is slightly different. I have been told that the pump itself will change into the reservoir, and I have a previous pump that was removed from the truck because it was 'torn off' after the truck ran through a fence with the previous owner's drunk friend at the wheel. Other than the little molded return tube being bent, it seems fine. what I don't understand is how the pump unit can be universal if the return line is in different spots. At least with the tractor hydraulics i am familiar with, that doesn't make sense.

any help is appreciated.

 

[77 K20]

I kinda went thru something similar. My power steering pump was having issues and leaking. I went to NAPA and told them it is for a 1977 K20. They handed me a box and on the box was a picture of the "canned ham" reservoir (teardrop shape).

When I got my old pump off I opened the box and found a different reservoir. A quick search said most of the pumps themselves are compatible with most years. The reservoir I had just had a small skinny neck. The return line was slightly different also. It still worked since there is flexible hose coming off of it, it didn't matter.

They did make some different style pumps. Some are very similar. Some are not. Also some were for hydroboost.

what I used to have:

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what I have now: Guess it is an older style.

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[heviarti]

I'm hoping someone can get very in-depth, since i am effectively hacking the pump. I have found that the fitting for the new style metric hose unscrews and the old style flare fitting fits in. I do have the style on top; I have three pumps, the '94 (metric thread for brackets), the old pump, and the installed pump (which is dookie). Obviously i can disassemble the pump itself from the reservoir, and possibly change it into one of the others to fix the orientation (so I can install the bracket) but how does the return work? What do i do to remove the reservoir without destroying it? do the auto store chains carry a set of gaskets and seals related to just a reservoir swap? anything i need to pay close attention to? I am looking for some deeper tech, interchanges, yadda yadda.

 

[77 K20]

I don't have the instructions for the pump I bought, but they did have in there about the only difference was that metric pressure line in the newer ones. Just take the fitting off of the old pump and move it over.

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Found an article that says the same thing:
http://www.hotrod.com/how-to/chassis-suspension/ccrp-1212-power-steering-fix-junkyard-builder/

A seal kit for the pump is pretty cheap.

http://www.mattsoldcars.com/RestoreAmerican/pspump.shtml

 

[MadOgre]

FYI the pump and the reservoir are 2 different things. The pump is round and is press fit with a rubber seal into the reservoir from the front. You have to remove the fittings and bolt on the back to remove the pump from the reservoir. Unless your reservoir is damaged you only need to replace the pump.

The fitting on the back is threaded into the pressure out put port of the pump itself. Thus the reason for a threaded fitting. The tube on the side of the reservoir is a return line and simply allows your steering gear box to return fluid to the reservoir.

The hydro boost units have 2 return lines on the reservoir. The hydro boost pump itself can be used on gas or diesel applications but uses a smaller pulley for diesel and larger pulley for gas applications to keep the pump speed the same for both applications. The hydro boost pump is designated HD at the parts store.

The pump simply draws fluid from the reservoir and sends pressurized fluid out the threaded fitting at the back of the reservoir.

The hydro boost system sends pressure to the brake system and then the same pressure is sent to the steering box. However both the brake system and the steering gear have return lines to the reservoir.

 

[heviarti]

Pump is refit. That return line sure is a drag. Off to the brake forum.