Bill Litosky, the service manager at Bergey’s Mack and Volvo of Franconia, Pa., provided detailed information about how to maintain and troubleshoot the power-steering system.
Grease all the mechanical parts of the front suspension and steering system at least every 15,000 miles to keep parts like kingpins from binding. This may require putting the front axle on secure jack stands to take the weight off the wheels — check your owner’s manual. Hard steering is commonly a result of neglect there, not trouble with the power steering.
In your pre- or post-trip inspection, check the fluid level. Refill with the fluid recommended on the reservoir, normally Dexron II or Dexron III transmission fluid. Wipe the dipstick cover off, pull the dipstick out and put in fluid until it reaches the upper line. On most reservoirs, there is a filler cap that is larger than the dipstick cover that you remove to pour in the fluid. On some, the filler cap and dipstick are combined.
On some reservoirs, you may need to remove the top by rotating it counter-cloc kwise with a wrench, then pulling it off. Use a syringe to remove a few ounces of fluid and pour it into a clean glass jar. Inspect if for significant amounts of bright metal or obvious moisture content. If it is contaminated, have the system flushed and the fluid replaced. Replace the filter with a new one. Refasten the filter by tightening the wingnut, or reinstalling the reservoir top with a wrench, using new gaskets.
Once the hose is replaced, refill the reservoir and start the engine, rotating the steering wheel back and forth and keeping the reservoir full to prime the system. Make sure the system is full and the steering response steady before operating on the road.
Litosky says hard steering in both directions suggests a worn pump, while hard steering in only one direction suggests a bad steering box. But hard steering not attributable to the mechanical parts of the system must be troubleshot by a technician using an expensive set of gauges. Get a pro to troubleshoot the system to be sure.
If the problem turns out to be a steering box, it will have to be replaced with an exchange remanufactured one. Litosky says this is a difficult job that takes two technicians, and is especially difficult when the box is mounted on the inside of the frame, as is often the case.
This is a job best done by the pros. But taking care of the fluid and filter and greasing the steering to minimize the stress on the power-steering system will delay all major repairs.