Everyone seems to be counting their pennies these days, which translates into less money available for automotive repairs. In the case of our '76 Corvette, it was the car's power-steering unit that needed attention. The system worked fine when the wheel was turned left, but really had to be muscled in the other direction.
We decided to enlist the help of Jim Phillips Automotive, whose techs walked us through the diagnostic process they would normally employ in a case like ours. In the pages that follow, we'll show you the steps behind that process and provide you with all the information you need in order to make the necessary repairs yourself.
If thoughts of a redlined bank account are flashing through your mind at this point, don't worry: We'll be keeping the project as affordable--and as straightforward--as possible.
Our first step was to make sure the power-steering-fluid level was within range. With a low fluid level, the pump can suck in air, causing noise and a loss of power assist. We kept our fingers crossed that this was the case, but when we checked our Vette's reservoir, it wasn't even a drop low.
Next on the list was to check the operation of the power-steering pump. We did this by revving the motor and then attempting to turn the steering wheel to the right. Had the elevated revs made the wheel easier to turn, it would have been a good indication that the pump was faulty. They didn't, so we crossed the pump off of our list of suspects.
All of the belts were checked and found to be at the proper tension. By now we knew the belts, the power-steering pump, and fluid level were all in fine shape. The next step was to check the steering rack to see if it had a bad valve or was over-packed with grease.
With the car lifted, we tried to adjust the steering by turning the adjusting nut with the engine running. The nut is located on the end of the power-steering control valve, under a cap. (Note: Exercise caution while doing this, since even a small adjustment can cause the steering wheel to twist violently in your hands.) Adjusting the nut had no effect on our car's steering.
At this point, it was apparent that the control valve wasn't functioning properly. We elected to go with a new valve, since it was less expensive than purchasing a rebuilt unit. The valve came with a new bolt, a new cotter key, and a castellated nut for the pitman arm.