Power Steering Pumps
Thread Starter
Instructor
Joined: Oct 2007
Posts: 137
Likes: 0
From: Nottingham
Power Steering Pumps
Hi all,
Im looking to replace my power steering pump with a new chrome resevoir one, i intend to use the same brackets altho this is not an issue if i have to change for new.
My 1977 has A/C and was fitted with a 3 groove pulley on the crank.
When i looked on summit they list different types for upto 74, saginaw, saginaw P series etc.
Can someone explain what the differances are, i.e. what is the differance bewteen a 74 and 77 pump, the differance between saginaw and saginaw P series and what i should look for apart from linning up the V grooves and hose fittings.
TIA
Wev
Im looking to replace my power steering pump with a new chrome resevoir one, i intend to use the same brackets altho this is not an issue if i have to change for new.
My 1977 has A/C and was fitted with a 3 groove pulley on the crank.
When i looked on summit they list different types for upto 74, saginaw, saginaw P series etc.
Can someone explain what the differances are, i.e. what is the differance bewteen a 74 and 77 pump, the differance between saginaw and saginaw P series and what i should look for apart from linning up the V grooves and hose fittings.
TIA
Wev
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
The power steering pumps changed designs. During the74-77 model years, I can't remember right off hand. The early pumps were made where the pully was secured to the pump shaft by a nut that threaded on the end of the pump shaft. The pully has a key-way in it that made it so you had to install it onto the pump shaft that has the woodruf key installed, much like how a harmonic balancer is attached to the crankshaft. The reservoir is shaped differently on the early designs where it has more of a bottle neck design reservoir. The later pumps use a taper seat that holds the pulley to the pump shaft. It requires a special tool to remove and install the pulley. I am not at work but I do believe that the pulleys are different because some are cast iron and others are stamped steel and the off-sets may be also different. The main thing that I look at , which is important, other than the pulley line-up issue is that the return line tube or pipe that is welded to the backside of the reservoir is angled the SAME as the original. If it is not you can have problems with your hoses due to the binding issues that can reuslt in the return pipe not being properly angled to prevent hose damage or pressure issues while turning the wheel.
Last edited by grandmastercorvette; May 5, 2009 at 06:32 PM. Reason: error in text
Thread Starter
Instructor
Joined: Oct 2007
Posts: 137
Likes: 0
From: Nottingham
Thanks for the reply, are the dims the same on both early and later pumps, i.e. the pumps would fit as long as i have the orginial bracket?
and do the models without A/C run of a twin groove crank pulley with no conversion?
and do the models without A/C run of a twin groove crank pulley with no conversion?
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
Will have to look that info up when I get to work tomorrow. I know that the mounting brackets are the same for small blocks regardless of the design. The issue is to the best of my memory is that the crankshaft puylley is a two groove. If the car came with power steering they added another pulley to it and thus now there are three grooves at the crackshaft by using two pulleys. I will check if the off-set on the cast iron pulleys for the early design pumps will be enough to be able to use a crankshaft pulley that only has two grooves. I will let you know tomorrow, but I doubt that it will....from memory that is.
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
There IS a difference in the off-set of the pulley from the early to late design. I do not know the distance but I know that there is a difference. I oddly enough do not have any late design p/s cars in the shop right now, only early. But I called my used parts connection and he verified that there is a difference.
Burning Brakes
Joined: Sep 2005
Posts: 895
Likes: 4
From: whitman massachusetts
1977 Pump
Check out Hurst Tuff Stuff pumps on the Summit website. They make a new,not rebuilt, direct replacement chrome pump for your 1977. It will accept your stock press-on pulley, and IMHO is a much better deal than a rebuilt. Be sure to rent the correct tool from your local parts store for both removal and installation of your stock pulley. Any other way will not only ruin your pulley, it will also damage the pumps internals. Most important aspect of these pumps is correct flow rate and pressure. Corvette pumps were designed to operate at 900 PSI, much lower than other full size car pumps. Good Luck!
