Car Care
Steering Power
Inspecting and replacing power steering
Created by Mike BumbeckA power steering pressure hose failure can be dramatic. Even a small hole in a pressure hose can cause power steering fluid to rapidly exit the system, usually landing all over something hot like an exhaust manifold or pipe. Combine this smoke show with a steering pump screeching from the sudden loss of fluid, and you might think world war three was commencing under the hood. Power steering system maintenance is the best way to avoid any smoke shows or sudden loss of power steering ability. The best time to replace a power steering pressure hose is before catastrophic failure. Monitoring fluid levels will provide an alert to power steering system leaks.
Simple in Theory
The system is fairly simple. A reservoir holds the power steering fluid. This reservoir can either be on the power steering pump or remotely located. The power steering pump is at the heart of the system. The pump itself takes power from the engine via an accessory belt. The pump pushes the fluid through a pressurized hose to the steering box or steering rack. Another hose brings the power steering fluid back to the reservoir once the power of pressure has been used to turn the wheels to and fro. In this way the show can go on and even the tiniest of humans can drive and parallel park an enormous vehicle without ending up with giant arms.
Hot Under Pressure
The power steering system takes advantage of hydraulic pressure. Fluids do not generally like to be compressed. Confine and pressurize hydraulic fluid, and this pressure can be employed to move elevators up and down or tilt over dump truck beds full of rocks. In the case of the automobile, this same principle is used to make steering a relatively effortless affair despite the wheels rolling along under three or four tons of sport-utility vehicle. Over time the rubber in the hoses can wear out. Inspect power steering hoses every other oil change. Look for dirt gathering around hose unions or the telltale drip on the driveway. Spongy, cracked, or leaking pressure hoses should be replaced.
Step 1
Where is all that power steering fluid going anyway? Inspect hoses and unions. Obvious leaking is easy to spot. Slower leaks are a bit trickier. Look for dirt gathered around one greasy spot.
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Step 2
Determine which is the pressure hose and which is the return. The pressure hose will generally be the one that's leaking, and have threaded fittings on either end. The return hose will have hose clamps.
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Step 3
Apply penetrating oil on the end fittings of the power steering pressure hose. These bolts have usually been in there for a while, and can be stubborn to remove.
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Step 4
Place a drain or catch pan under the low point of the pressure hose. The law of gravity also applies to liquids. Use a flare nut wrench to break loose the hose fitting. Another trick is to use a plug on the hose end once removed to prevent leaking.
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Step 5
Hose routing can either be simple or downright crafty. Remove and save all clamps and shields on the way to figuring it out. Loosen and remove the rack or steering box end of the power steering hose. Use a flare nut wrench! Chances of stripping the bolt are high with a standard box wrench.
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Step 6
Tighten everything back up and add power steering fluid to the "cold" level in the reservoir. Start the vehicle and turn the wheel lock-to-lock a few times to bleed the system of air. Top off power steering fluid. Repeat until system is free of air.
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