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How to Stop a Power Steering Pump With a Whining Noise

by Chris Stevenson

Of all the components or parts on the automobile engine, the power steering pump will be the part most likely to announce warning signs of its poor operation or failure with some very demonstrative sounds. Some would call it "whining," "squealing" or even a loud hissing sound. Although some amount of hum can be expected from a device that uses vanes to push fluid through a valve and lines at high pressure, the power steering pump can really start to scream when it approaches failure.

Refrain from turning the steering wheel all the way against its stops (left or right) while the engine idles or during low-speed turns. Forcing the steering wheel to its maximum turning radius cuts off the flow of fluid to the pump, which causes an automatic pressure relief. This causes forced circulation within a confined area and can raise the temperature of the fluid to an extreme degree. This causes metal-metal contact inside the pump.

Place the vehicle in park or neutral with the emergency brake. Let the engine idle. Raise the hood and remove the cap on the power steering pump reservoir. The cap will have a plastic dipstick on the end of it. Wipe the dipstick portion with a rag and screw it back down on the reservoir. Unscrew the lid and check the level indicated on a marked scale on the dipstick. The level should read at the top "Hot" mark. Low fluid level will cause the pump to whine. Fill to the appropriate level and listen for noise.

Inspect the condition of the power steering fluid with the cap off the reservoir. It should be translucent red and slightly thick to the touch. Brown, black or sudsy-looking fluid indicates contamination. Power steering fluid that has lost its viscosity (thickness) cannot properly lubricate the seals, bearings and vanes inside the pump, which will cause a high-pitched whine or squealing noise. If the fluid feels gritty between the fingers, it means rust, metal shavings and dirt has entered the reservoir.

Use a slot screwdriver to loosen the low-pressure rubber hose clamp on the bottom side of the power steering pump reservoir. Catch any drippings in a pan. Loosen the high-pressure metallic line nut on the power steering pump body with a fuel line wrench. Let the fluid drain into a pan. Remove the reservoir cap and use a used turkey baster to suck out all of the power steering fluid. Clean the inside of the reservoir with a rag wrapped around a screwdriver.

Reconnect the rubber low-pressure side hose and tighten the clamp with a slot screwdriver. Screw the metallic line nut on by hand and finish tightening it with a fuel line wrench. Fill the reservoir with new (manufacturer's recommended) power steering fluid to the top mark. Start the engine and listen for noise.

Test the tension and condition of the serpentine belt, or the individual power steering belt. The belt should not be cracked or contaminated with oil or power steering fluid. Clean the belt with alcohol. Adjust the (individual) belt for tension, using an end wrench to loosen the adjusting bolt, and a socket and wrench to slightly loosen the pump mounting bolts. Pry the pump outward with a screwdriver to tighten the slack in the belt. Tighten the adjusting bolt with an end wrench. Tighten the mounting bolts with a socket and wrench.

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About the Author

Chris Stevenson has been writing since 1988. His automotive vocation has spanned more than 35 years and he authored the auto repair manual "Auto Repair Shams and Scams" in 1990. Stevenson holds a P.D.S Toyota certificate, ASE brake certification, Clean Air Act certification and a California smog license.

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  • ford mustang's steering wheel image by Lario Tus from Fotolia.com