I fixed my power steering (PS) pump problem. A tech tip from Cardone was helpful, which is a major US manufacturer of new and reman pump and various other automotive components.
Here is a link to the tech tip I followed to fix my issue:
http://www.cardone.com/tech-help/steering/how-it-works-best-practices/steering-system-flushing-use-the-buddy-systemBefore removing and replacing my pump (which worked prior to removing it before pulling and rebuilding the engine this past summer) I thought I would try Cardone's PS pump flush process then bleed the system again. I followed the flushing process and replaced the PS belt to make it was snug, and my PS now works great.
I did not have a "buddy" to assist as the Cardone's tech tip suggested, so I had to take my time to do the process solo. To flush the system and remove any trapped air in my PS gear box, I followed this process. It is similar to the process that Boston14 and Ed have offered above. Removed the PS pump return hose from the pump and directed it into a catch pan. Quickly after pulling the hose pushed a rubber plug over the outlet tube on the PS pump reservoir. It is a messy process so you have to prepare. I lined my front suspension area under the pump with a plastic trash bag and some paper towels to catch and absorb the leaking fluid. Top off the PS reservoir level to within about 1” from the top of the reservoir. Disconnect the coil wire to prevent the engine from starting, and crank it for about 10 seconds. Check and top off the PS fluid level as needed. Check the fluid in catch pan to see if it is dirty or discolored.
I did not get much drainage while cranking the engine because I did not want to continue to crank the engine for extended periods while turning the steering wheel lock-to-lock to pump the fluid thru the PS gear box. After cranking the engine, I left the key in the ON position so I could turn the wheel lock-to-lock 2 – 3 times which pumped and flushed the old fluid out of the PS gear box. I continually checked and topped off the fluid level in the reservoir, then cranked the engine again for about 10 seconds, followed by rotating the steering wheel lock-to-lock 2 -3 times. I followed this flushing process 3 – 4 times which completely flushed the PS gearbox and reservoir of the old fluid until clean fluid was observed in the catch pan. Drain and wipe the catch pan clean each cycle to help determine if the fluid drained is clean. You may use up to a quart of PS fluid during the flushing process so it wise to have two quarts on hand. You will learn on Cardone’s website that not all PS fluids are created equal so buy a quality fluid. PS fluids are not regulated with API Service ratings like motor oils so chose your fluid wisely and do your homework.
Once you verify the fluid is clean from flushing process, reinstall the PS return hose the reservoir and make sure the holes clamps on both ends of the holes are tight so they do not suck in air. If your hose is old, hard, and brittle, is wise to replace it.
Now follow the bleeding process as outline in the Chevrolet Service Manual which involves lifting the front wheels off the pavement. Reconnect the coil wire and verify the PS fluid level is at the correct level (some where between the COLD and HOT level on the cap stick) Start the engine for only about 2 – 3 seconds then top off the fluid level if necessary. I stated my car again for only about 5 -10 seconds and the verified the fluid level was correct. It is critical that you do not rotate the pump and suck the reservoir dry of fluid and damage the pump.
Start and run the engine at 1500 RPM (temporarily set your idle speed if necessary to maintain 1500 RPM) and then SLOWLY rotate the sheering wheel lock-to-lock several times. Do not hold the wheel against the stop for extended period as this only generate high pressure in the system and does not help the bleeding process. Simply rotate the steering wheel slowly toward the locks to get full gear box rotation. Shut off the engine and allow the PS fluid to settle and verify the level on the cap stick. Check for bubbles in the fluid or foaming. Foaming in the fluid may be a sigh of other problems that you can read about on the Cardone website. Restart the engine and follow the bleeding process 2 – 3 more times, shutting off the engine in between the bleeding cycles. Always make sure the fluid level is maintained.
After bleeding is completed, lower the car with the front wheels on the pavement, preferably a smooth garage floor. Start the engine and rotate the wheels under the resistance of the pavement and you should experience smooth PS action lock-to-lock with no squealing or grinding sounds. If you continue to have PS system issues, it may require bleeding again so be patient.
This process helped me and I hope you find it helpful.
