Removing the PS Pump from the Vacuum Pump

[TLarsen]

How do I separate the PS pump from the vacuum pump on a '91? From what I've read, this is the "early" style vacuum pump, it is relatively short, and has no oil supply line from the engine.



I have the pumps removed from the engine already and of course the 4 nuts holding the PS pump to the vacuum pump have been removed. When I started pulling the two apart the shaft in the vacuum pump and the gear were pulling and moving with the PS pump, so I stopped to make sure I wasn't damaging something.



As far as I know, both pumps are functioning normally, and have no major leaks. The whole assembly is generally oily however. Since I have the engine out of the donor truck and torn apart, I thought I might replace the seals between the pump.



Also, since I am installing this engine into a '75 W200 with a reverse rotation steering box with flared SAE hose fitting, so I want to use the '75 PS pump to avoid custom hoses. What's the possibility of the '75 Saginaw pump fitting the '91 vacuum pump?

 

[R C Cola]

Pumps

I have 455k and the pumps have never been off mine yet. I have had steering oil leaks and so far it was o-rings and hoses and connections. My mechanic told me the seal between the two requires taking the vacuum pump apart and putting the seal in from the inside (pricey). Turned out we did not have to do that thank goodness.

 

[PToombs]

Just swap the pressure (large ) fitting from one pump to the other. A 1 inch wrench will do it. Be careful, there is a spring and a plunger under the nut. If the truck steers hard or too easy, swap the plunger. Start with the plunger from the '75.

 

[sdstriper]

Gear/eccentric/bearing removal

You'll need to make a "pin", place the pin in the shaft, tighten a bolt against it to draw the gear/eccentric/bearing off the shaft.



I qoute the "pin" dimensions from the FSM: Make a pin from 8mm or . 312 hardened drill rod or a 10. 9 or SAE Grade 8 capscrew. The Pin is 2 inches in length or 50. 8mm



I had a note in my manual; 2 3/4 inch bolt, 1" o. d. washer and square nut.



I used the shop vice at some point I remember and swearing was involved...

 

[tugboatphil]

at some point I remember and swearing was involved...

Isn't it always! :-laf :-laf :-laf

 

[Philip]

swearing was involved...

That normaly follows a sharp pain in a thumb. Then a constant throbbing follows after the sharp pain. :-laf :-laf

 

[TLarsen]

Just swap the pressure (large ) fitting from one pump to the other. A 1 inch wrench will do it. Be careful, there is a spring and a plunger under the nut. If the truck steers hard or too easy, swap the plunger. Start with the plunger from the '75.

Great idea! I didn't think of that. Thanks.

 

[TLarsen]

You'll need to make a "pin", place the pin in the shaft, tighten a bolt against it to draw the gear/eccentric/bearing off the shaft.



I qoute the "pin" dimensions from the FSM: Make a pin from 8mm or . 312 hardened drill rod or a 10. 9 or SAE Grade 8 capscrew. The Pin is 2 inches in length or 50. 8mm



I had a note in my manual; 2 3/4 inch bolt, 1" o. d. washer and square nut.



I used the shop vice at some point I remember and swearing was involved...

Sounds like a lot more work than seperating the newer pumps. Since the '91 PS pump appears to be a reman unit, and not very old, I'm going to try PToombs suggestion and leave the pumps together.

 

[sdstriper]

Work smarter, not harder

 

[PToombs]

That's what I try, it just doesn't always work out that way! :-laf :-laf