Power steering pulses

57 Bel Air nearing completion...long road with alot of bumps. Latest bug: My mechanic rebuilt the power steering control valve, and installed a new hydraulic cylinder and hoses. On first startup, steering wheel would turn itself all the way to the right lock. After a lot of rotatating steering wheel back and forth that problem is gone, but wheel still "jerks" or pulses as you turn it. One mechanic said this is because of air in the system which will take a long time to bleed out. I have also heard mention of "adjusting the control valve" or reversing the hoses. Anyone know what adjustment to control valve? The car was running when I bought it and power steering worked fine but leaked, thus the rebuild of control valve and replacement of cylinder. We've worked on rotating the wheel, probably 100s of times with engine running and not running. Anybody have and ideas? Thanks in advance

It doesn't take a long time to bleed the air from the system. It self bleeds. With a system that's been apart, you fill the reservoir full to the mark on the dipstick, jack the car up so that the front tires are off the ground, and turn the wheel from one extreme to the other a few times (don't start the engine yet). Check the fluid after each excursion of the steering wheel and top off. Now you can lower the car and start the engine. Immediately shut it off, check fluid level, and top off. Start the engine again and turn the steering wheel a few times. Check the level and top off. By this time you should have bled all the air from the system.

If you ever let the level get too low, you'll be pumping air into the system and the fluid will foam up. If this happens take a break and let the bubble/foam settle down.

If the hoses are reversed, the steering wheel will run away in the opposite direction you try to steer. I.e., if you turn the wheel to the left, it will run away to the right. So quick it may hurt you if you don't get your arm/wrist out of the way quickly. It doesn't sound like you have this problem.

I don't think the 55-57 power steering valve is adjustable after installation like later ones. Later ones have an adjustment to center the valve. (Someone correct me if wrong.)

The shop manual covers the power steering system. It's available on line (maybe on this site). You should look it over.

The guru of rebuilding stock power steering is Steve at authenticautomotive.com. He has everything you need both parts and knowledge.

I'm pretty sure that even with the older 'cylinder type' power steering systems such as the GM systems of the fifties/sixties, that the control valve is adjustable to 'zero' out movement when there's no input.

Here's a super chevy tech article video with photos that explains and go thru the replacement of the control valve; the fifties Chevy PS system works the same as the C2/C3 Corvette systems.

http://www.superchevy.com/how-to/car...-82-corvettes/

The C2/C3 p/s stuff, as well as 55-64 full size and 62-67 Chevy II/Nova, all work on the same principles with similar looking components. I don't know when they switched, but the later stuff had a hydraulic valve centering adjustment that could be done on the car with the system nearly fully assembled. The adjustment was done with the hydraulic cylinder mechanically disconnected from the center link. The 55-57s didn't have this adjustment as I understand.

Again, Steve Pratt at authenticautomotive.com is the guy who will know about all this.