Steering Issues Caused by Air and Loss of Pressure

April 2, 2011/Autoweb Classifieds

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

Dear Doctor: I have a 2005 Subaru WRX STi that I purchased in 2007 with 36,000 miles. It now has 82,000 miles and for the past year or so, the steering tends to cut out on me. I noticed it happens more on turns when I’m either accelerating or going over bumps. I’ve had a few instances where I couldn’t turn and had to back up and use both hands to turn the wheel. Would bad belts do this, or could it be the steering box? Rick
Dear Rick: There have been some problems with air entering the power steering system from a faulty inlet o-ring. This causes a loss in pressure, because the pump has passed the air in the pressure line. Have the technician check the inlet o-ring for wear.
Dear Doctor: I have a 2004 Pontiac Grand Prix with the 3.8L and Magnasteer. When pulling out of the driveway at a slow speed the steering makes a buzzing sound while turning the wheel. This does not happen while driving at normal speeds. I flushed the power steering fluid with no change in the noise. I found Technical Service Bulletin #01-02-32-001 that states to lubricate or replace the intermediate shaft. Could this resolve the problem? Ralph
Dear Ralph: I’ve replaced a lot of power steering pumps on these vehicles. The buzzing sound is usually from a faulty power steering pump or air in the system. The intermediate lower steering shaft has been a problem for GM vehicles since the 1990s on both cars and trucks. I have also seen small o-rings on power steering lines cause air to leak into the system and cause noise. A full check of the system is needed.
Dear Doctor: I’ve leased a 2010 Toyota Prius for three years. I only drive 5,000 miles per year and I am concerned that the brakes will freeze up due lack of use. Besides driving unnecessary miles, what should I do to prevent this? Are there stainless steel replacement parts for these brakes so they will not freeze? The recent auto reviews in “Consumer Reports” show a poor rating for this model-year. Tom
Dear Tom: Every magazine has an opinion. Most of the time, I do not agree with car and consumer magazines.

Remember, I work on these vehicles six days a week. I have no problem with the brakes on this vehicle. Any vehicle that is left sitting outside in the weather will build up rust on all moving parts that are exposed to the elements. Have your local technician pull the wheels and remove the brake caliper slide bolts and check to make sure they are clean and not binding and moving freely. While they are inspecting the brakes, have them give a complete inspection of the vehicle.
Dear Doctor: I own a 1997 Ford Explorer with over 200,000 miles on it. It is stuck in park. I checked the fuses but these didn’t correct the problem. I’m able to move the truck by turning the key one position, moving the column shifter to neutral, starting the truck completely and moving the shifter to drive. But the brake lights do not work and when I put the truck in park it gets stuck again. What else can I do? Tristan
Dear Tristan: A very common problem is the brake light switch, or broken wire at the switch — not a fuse. The safety shift interlock is powered from the brake light switch. When you step on the brake pedal, the shift interlock solenoid gets it’s power then releases the solenoid allowing the shifter to move.
Dear Doctor: For many years I drove a manual transmission vehicle. Recently, I purchased a new sport utility vehicle with an automatic transmission. Does it damage the transmission to put it into neutral before I put on the brakes? John
Dear John: It will not damage the transmission or drive line at all. Today’s automatic transmissions are computer-controlled and deliver great performance. — Junior Damato, Motor Matters

Junior Damato is an ASE-certified Master Technician.

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Copyright, AutoWriters Associates, Inc., 2011