It has been said you can move the world with the power of hydraulics. In our case, we just need it to make the steering effort a little easier. Classic C2 and C3 Vettes have a conventional Saginaw worm-and-sector steering gear, which does the job quite well unless you’d prefer less steering effort. Excessive steering effort was relatively negated during the first 10 years of Corvette production. A large-diameter steering wheel and skinny, pizza-cutter tires reduced steering effort, but not by much.
Chevrolet added optional power steering to the Corvette’s underpinnings beginning in 1963, encompassing an engine-driven pump, pitman arm control valve, pressure and return hoses, and a power ram to provide assistance in turns.
Corvette “power assist” steering has long been a very effective tool in reducing steering effort while keep us in touch with road feel, which is why Corvettes were equipped with this type of power steering to begin with. This wasn’t a GM exclusive. Ford used this Bendix-design “power-assist” steering design on a wide variety of vehicles ranging from the humble Falcon to the behemoth Lincoln. Farm tractors were even fitted with it.
We call it power-assist because it provides hydraulic assistance to the Corvette’s existing steering system. When you move the steering wheel left or right you are moving a control valve bolted to the pitman arm that directs hydraulic pressure to one side of the power ram (also known as a slave cylinder) at the drag link to assist steering effort. This system works very well when the lines are properly connected and the seals have integrity.
Particularly problematic with C2/C3 power steering systems is control valve adjustment and leak issues. These systems leak at the control valve and they can also leak at the power ram. If the control valve is out of adjustment too much pressure will be applied in one direction or the other and steering will pull left or right. This can be corrected with proper adjustment at the control valve via an adjustment screw with the engine running and both front tires off the ground.
You can also potentially get hydraulic lines backward during installation from the control valve to the ram and steering becomes erratic quickly. When lines are backward to the ram you steer left and the ram applies pressure right snatching the steering wheel out of your hands violently. This won’t happen if you pay strict attention to how the lines and hoses are routed and installed before taking the system apart.
If the hydraulic lines are not properly seated and tightened in the control valve and ram, they can leak. Nicks in the fittings and seats will cause leaks because there’s a lot of pressure going on here. When properly assembled, these power steering systems perform reliably.
Lonestar Caliper Company offers a complete line of power steering parts, components, and systems for C2 and C3 Corvettes, including pulleys, power steering pump caps, power steering brackets and steering shaft couplings. Because quality is so critical, Lonestar Caliper rebuilds all of its power steering pumps, rams, control valves and steering gears in-house.
Corvette engine front accessory drive packages were revised over time as vehicle design changed. Three basic types of Saginaw power steering pumps were used in C2 and C3 Corvettes. There’s the 1963-’74 “long-neck” Saginaw pump, which is clearly different than the “canned-ham” 1975-’82 Saginaw pumps to follow. The difference in pumps is more about pump reservoir shape, fittings and shaft type than anything else. The long-neck pump has a keyed shaft and pulley versus the pressed-on pulleys used from 1975-’82. The 1975-’79 “canned-ham” pump is very similar to the revised Saginaw pump used from 1980-’82. It is very important to understand the differences in these pumps and order the correct one for your application.
Lonestar Caliper power steering pumps are not equipped with drive pulleys, which means you will need to use your existing pulley or order the right one for your application. Be prepared for differences in front accessory drive packages on small- and big-block Chevys from 1963-’82, which can affect the compatibility of parts and pulley alignment. If your Corvette was not equipped with power steering from the factory, you will have to change out or add to the crankshaft pulley to accommodate the power steering pump.
When installing the new power steering system, begin with all new components and fresh fluid. When you service the pump with fluid, keep in mind as fluid gets hot it expands and can overflow out of the pump. You won’t even need one quart of power steering fluid to fill the system. Service the pump with just enough fluid to submerge the pump inside the housing. Run the steering wheel lock to lock several times to bleed out air. Then, service the pump to “full” on the dipstick at operating temperature and you’re good to go. Change the power steering fluid whenever you change the transmission and rear axle lubrication, which should be roughly every 30,000 miles.
We’re working with technician Paul Taylor of Hot Rods by Dean in Phoenix, who is going to walk you through the C2/C3 power steering system. Replacement of this system is straightforward because Chevrolet made it so simple to service. Because the system is external, everything is easy to access. Let’s get started. Vette
1. Installation begins with a new power steering-specific pitman arm, which slips onto the sector shaft like this. It is virtually impossible to get this wrong because the sector shaft is splined to fit the pitman arm as shown. GM torque specs for the pitman arm nut is 120-160 ft-lb.
2. The power ram shaft A-bracket attaches to the lefthand framerail.
3. We’re installing a new idler arm from Lonestar Caliper. C2 and C3 Corvettes used the same idler arm from 1963-’82 for both manual and power steering applications.
4. Lonestar Caliper remanufactured power steering control valves are built in-house to ensure quality. The control valves are factory adjusted and ready for installation.
5. The power steering control valve threads onto the drag link as shown. There is an indentation in the threaded portion of the drag link, which is where the bolt is positioned in both the valve and the drag link. This locks the control valve exactly where it belongs. When the control valve is fully threaded onto the drag link, no threads should be exposed.
6. The power steering control valve is connected to the pitman arm and drag link as shown. Note how the control valve is fully threaded onto the drag link and secured with a Grade 8 bolt. The castle nut at the pitman arm needs to be tightened and secured with a cotter pin. Never use any hardware less than Grade 8 on steering and suspension components.
7. The other end of the drag link on the right side is secured to the idler arm with a castle nut and a cotter pin (yet to be installed). Always cut your cotter pins short and bend them over to where they’re not likely to injure someone during maintenance.
8. The power ram is installed next—secured at the drag link and at the A-bracket at the lefthand framerail. The drag link end is secured with a castle nut and cotter pin. At the A-bracket there are two rubber bushings, a nut and a cotter pin.
9. Here’s a close-up of how the power ram is tied to the A-bracket with two rubber bushings, beveled washers, a conventional fine-thread nut and a cotter pin. Trim the cotter pin clean and wrap the legs around the shaft.
10. Both the control valve and the power ram have been installed and safely secured. The steering wheel should be centered except when you need to move the control valve left and right during line installation.
11. The control valve-to-power ram lines have been installed and tightened. Always inspect line flares and seats at both the valve and power ram for any damage prior to installation. Any nicks or scores in the flares or seats are reasons to replace because they will leak. There is a lot of pressure going on here—1,000-1,200 psi.
12. The pressure and return lines from the Saginaw power steering pump have been connected to the control valve. Always inspect the lines and fittings for damage before installation. It is a good idea to tighten fittings to initially seat the flare, loosen and tighten again firm.
13. The control valve, ram, and lines are all connected as shown. Run the steering wheel lock-to-lock and inspect lines and hose clearances. Make sure the return hose doesn’t rub against anything as you run the steering wheel lock-to-lock.
14. We have installed the tie-rod ends from Lonestar Caliper, which sport OEM-style grease fittings and adjustment sleeves. It is suggested you measure the new tie-rod ends off the originals if you still have them to get the toe setting close to where you can make it to an alignment shop. The castle nuts at each end are tightened and secured with new cotter pins.
15. The inner tie-rod ends are secured to the drag link as shown. Make sure all the grease fittings in the tie-rod ends and idler arm get a shot of chassis lube. You don’t have to inject much lube into these joints, just enough to where it becomes visible at the boot.
16. Lonestar Caliper has provided us with the complete Saginaw “long-neck” power steering pump, hoses and hardware common to the 1963-’74 Corvette. This is a very simple affair with pivot and adjustment brackets, which bolt onto the engine block using the Grade 8 bolts provided. The pressure and return hoses have been provided.
17. The power steering pump adjustment bracket bolts to the front and left side of the block as shown here. The Saginaw pump backs up to this bracket with a slider adjustment where the bolt threads into the back of the pump.
18. The pump and bracket bolt together as shown. Two bolts on the left screw into the block along with the slider bracket just shown. The pivot bolt at the bottom of the pump is part of the adjustment process. Both the pivot and slider bolts lock in the adjustment.
19. Here’s the pump and brackets installed and secured. The 1963-’74 Saginaw pump has a keyed shaft and a slide-on cast pulley. From 1975-’82, the “canned-ham” Saginaw pump sports a pressed-on pulley.
20. Behind the pump, we get a look at the pivot bolt and nut, and both the pressure and the return lines. The return hose from the control valve is low pressure line secured with a worm-gear clamp. The pressure line screws into the pump. Make sure all lines and hoses are not touching anything to prevent chafing and leakage.
21. You can expect three basic types of Saginaw pumps. This is the “long-neck” pump common from 1963-’74 with a keyed shaft as mentioned earlier. From 1975-’82 the pulley on “canned-ham” pumps has to be pressed on.
22. Paul Taylor of Hot Rods by Dean has installed and tightened the pump pulley locknut to 60 ft-lb.
23. With the pump and all the pulleys installed, pulley alignment should be checked. Be mindful of this issue when you’re gathering pulleys, accessories, and brackets for your C2 or C3 Corvette. When you are mixing and matching brackets, pulleys, and even water pumps it can be dicey on fitment. The best advice is to stay close to what your Corvette originally had as a baseline for the front dress. Another issue is pump fitting and line compatibility.
Photography by Brian Brennan