Power Steering Fluid Flush
Power steering fluid transfers pressure, lubricates, and removes heat from the system. It must be able to withstand the high pressures and temperatures found in today’s hydraulic power steering systems.
When it turns dark brown or black colored, it has oxidized and lost its necessary properties. Particles from the pump and rack and pinion collect in the bottom of the reservoir. If not flushed, varnish will form, seals will begin to harden, and hoses will deteriorate.
Fresh power steering fluid contains additives that protect seals, hoses, and the power steering pump and rack and pinion from premature wear.
These systems usually contain a couple pints of fluid. Generally the exchange process includes using a fluid extractor or disconnecting the return hose from the pump to drain the fluid and then replacing the hose and refilling the reservoir. Then starting and immediately shutting down the engine. Repeat this process three or four times in a row to replace the old fluid.
The illustration shows a more complete flushing of the system. It may require a helper and several quarts of fluid depending on how dirty and contaminated the system is.
Always use the correct fluid and flush or change the fluid according to manufacturer’s specifications. Some manufacturers recommend flushing with a solvent free power steering cleaner before a regular fluid exchange or every 50,000 miles. It helps remove harmful deposits and debris that lead to power steering moans and squeals.