This is a Lee Power Steering filer assembly located on one of our Chevelles.
The filter prevents debris buildup on the pump or box and will ensure your system lasts a very long time. (Image/Jeff Smith)

I recently decided to upgrade my steering box in my S-10 pickup. I’ve read that the S-10 uses a very similar front suspension as the G-body cars from that same time period. So I ordered a 1988 Monte Carlo SS box. But the box only lasted about two weeks before it just quit working. So I returned the box as defective and ordered another one from a different company and the same thing happened again. Do you have a suggestion for a company that could supply a quality steering box? K.S.

Jeff Smith: We referred your question to Alan Padelford, the owner of Lee Power Steering in Valencia, CA and he offered a simple suggestion. He has tons of experience building custom steering systems along with steering boxes for race cars and off-road applications. He has discovered that dirt and debris in the power steering fluid can quickly disable an otherwise high-quality steering box because the high-pressure hydraulic circuits in a steering box use extremely tight clearances.

Given this situation, Padelford insists that anytime you replace a steering box it must be accompanied with a new pump and hoses to eliminate the potential for dirt in the system to be pushed into the new steering box. Which is likely what happened in your case.

Power steering systems are rarely—if ever—serviced by changing the fluid because there is no easy and quick way to do so. Assuming your S-10 has more than 100,000 miles on the steering box, it’s almost guaranteed that there’s an accumulation of dirt, debris, and corroded fluid that can cause all kinds of grief with a new box.

So to do a steering box conversion correctly, Padelford says you must replace all of the components, including the hoses. We can support that statement because we’ve experienced the same issue. We installed a new box in a Chevelle and within a month, the box would occasionally lock up and not turn left.

We tried making sure there was no air in the system but the problem kept reoccurring. It was a dangerous situation so we replaced the box and added a new pump, and the problem disappeared. We blamed this on a defective box originally but now realize it was likely a debris issue.

Padelford also recommends installing a 10-micron filter on the return side of the system to minimize debris. Unless you drive off-road or run more than 100,000 miles with this system, the filter will probably never need to be changed. He also recommends his own power steering fluid, but says that there are many quality power steering fluids on the market that will work.

He cautions avoiding use of automatic transmission fluid (ATF) in a power steering system. It will work in an emergency, but it’s best to avoid this fluid because it employs certain friction modifiers that aren’t good for power steering systems.

Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.