Any other cars use the same power steering pumps as the C3s ?

 

The answer is no. The things that make the Saginaw P-pump unique for the C3 Corvette are things such as; the metal reservoir, the flow control valve and spring; the discharge fitting; the cam ring; and the mounting studs.

Now, the good news is that all of the above parts are interchangeable between all of the other Saginaw P-pumps. So it is very possible to construct a Corvette P-pump from the core of another Saginaw P-pump.

One thing to be aware of: The power steering hoses in the C3 Corvette steering system do not like high pressures. Most GM power steering systems operate at 1450 psi. The C3 Corvette system was designed to operate at a maximum pressure of 950 psi. For instance, do NOT take a flow control from a pickup truck and install it in your Vette P-pump. (The valve will interchange!) The high relief pressure setting will quickly cause your hoses to leak. You want to use the flow control valve from your original pump.

You also want to use the original reservoir if at all possible. The direction and shape of the return oil spout on the reservoir is quite critical for good hose routing.

The Saginaw P-pump has been around for many, many, years. It is a marvel of parts interchangeability. Just be careful when it comes to mixing and matching parts.

Jim

 

Thanks , How or where did you learn so much about these pumps ?

 

I worked in Steering System Engineering for 39 years at Delphi Saginaw Steering Systems (formerly Saginaw Steering Gear Division, GMC).

I was never the pump engineer but I picked up a lot by osmosis. I was the supervisor responsible in the early 70s and 80s for C3 power steering hoses, flexible couplings, and all of the hydraulic and grease seals in the power steering pumps and gears.

Jim Shea

 

Jim, Nice answer. I am assuming that if I chunk the PS system in favor of a jeep box & hydroboost, then any ps pump will do, especially the later model remote reservoir system.

 

What's the round magnet inside the pump reservoir for ?

 

Jim,

How do I get the pulley off the PS pump on a 74

 

Jim,

How can I identify the flow control valve type (are there any identification markings)? I had a brand new high pressure hose leak immediately at full lock. I am not sure if the pump was a Corvette pump....came with the car in a box of bits

Thanks,
Joe

 

The magnet is to gather long term wear debris that is created from the pump vanes moving against the cam ring.

Before 1975, all GM pumps had a nut and key that held the pulley in place. Remove the nut and a light tap should get the pulley to come off.

Starting in 1975 all GM pumps were converted to an interference fit pulley attachment. If your pump does not have a nut on the end of the driveshaft, you MUST use the special tool that engages the pulley hub and pulls the pulley off by reacting against the driveshaft.

Most flow control valves with low pressure relief settings will have several small shims under the hex nut (with the built-in screen) on the end of the valve. I don't think that they are identified.

Jim

 

Thanks Jim, I'll inspect the flow control valves I have.

Cheers,
Joe

 

Is that indeed the case......that if using the Jeep steering setup with hydroboost that the higher pressure pumps are preferable?

- Alan

 

If you can stop the car, holding it with the foot brakes, and still steer all the way to full lock then you have enough pressure. The highest pressure that you will ever need will be a static steer with the car stopped and the brakes applied.

If you reach manual steering efforts before reaching full lock, then you need more pressure. In other words, you want to use the lowest pressure that will allow you to reach full lock.

The Corvette booster cylinder system requires only 950 psi. The Saginaw 600 integral power gear may require pressures around 1200 psi in a C3 Corvette with more modern bigger tires.

I do not think that the hydraboost braking system necessarily requires pressures over 950 psi. But I am not sure. I am quite sure that the hydraboost unit would have been validated at 1300/1400 pressures.

Jim