AfterMarketNews Auto Care Pro AutoProJobs Auto-Video.com Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service

The Problem With Living In The 'Now'

I once had a shop manager who concentrated on the “now.” Every day was a mad dash to complete the jobs at hand. He wanted to know who was working on what, where the parts were and when everything would be done. He was constantly reacting to a customer’s...

Read more...

ASE G1: Drive Belt Inspection, Replacement

The ASE G1 Certification test contains 55 scored questions, plus 10 unscored ­research questions, that cover a range of skills and knowledge related to maintenance and light repairs in engine systems, automatic transmission/transaxle, manual drivetrain...

Read more...

Amateurs and Hacks Provide Job Security For Automotive Service Professionals

Two cars pull up in front of my shop. The drivers didn’t come in, but I heard the commotion from my office window. The boyfriend opens the hood of his girlfriend’s car. They both stare at the engine; she tells the boyfriend that she was supposed...

Read more...

Audi Engine Timing Chain Failure Due to Lack of Maintenance

If you’ve been working on cars as long as me, you’ll remember the first timing belt you did and thought, “what was wrong with timing chains?” It was only a year ago, when I was working on a 2005 Audi A6 Quattro with a 3.2L engine with a broken...

Read more...

Acura: Clunk Noise While Turning

Model: Acura RSX 2005-’06 Symptom: The front suspension makes a ­clunking noise while turning. Probable Cause: The front springs are moving on the spring seats. Corrective Action: Replace both front springs and do a four­-wheel alignment. Diagnosis:...

Read more...

Inside Import Car Collision Warning, Automatic Braking Systems

Anything that moves under its own power also has to stop, so brakes have been a safety feature on cars since day one. Over the years, technical innovations such as antilock brakes (ABS) have ­improved the ability to stop with minimal skidding on...

Read more...

Bendpak Breaks Ground On New Warehouse and Shipping Complex

    BendPak, Inc. announced the recent groundbreaking to celebrate beginning construction of a 67,000 square-foot multipurpose warehouse and shipping center located on 3.7 acres of land in Santa Paula, CA. The new 67,000 square-foot...

Read more...

Pulling Codes: 7 Common Causes of Misfire Codes

A flashing check engine light and a P0301 to P0312 diagnostic trouble code (DTC) is a surefire indication that one or more cylinders are misfiring. Occasional misfires may pass unnoticed, but a steady misfire is hard to miss. The engine usually feels...

Read more...

Analyzing the Cylinder Pressure Waveform from a Running Engine, Part 3

By Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   In Part 1 of this Maximizing Tools series, we discussed an alternative approach to diagnosing an engine...

Read more...

‘Green’ Bullets: Tips for Servicing Hybrid Vehicles

Newsflash: Hybrids are here to stay. The oldest Toyota Prius models are now 14 years old and many other hybrids from other manufacturers are crossing the 100,000-mile mark every day. Here are a few of my Silver Bullets, — or in this case “Green...

Read more...

Legendary Spark Plugs: The Six Toughest Vintage Spark Plug Replacements

1. AMC Pacer: The Pacer was supposed to get a GM Wankel rotary engine. If this were the case, the four plugs would have been easy to access. But thanks to emissions problems, the Pacer would get the regular AMC straight six. This forced the engineers...

Read more...

Battery Service and Diagnosis

A good battery with an adequate charge is absolutely essential for reliable cold starting. A weak battery, or one that is rundown, may not deliver enough amps to crank the engine when temperatures plunge and the oil thickens. Cold weather can be hard...

Read more...

Home Chassis Power Steering Racks: Leaks & Repairs

Print Print Email Email

Power steering is a wonderful invention, especially for those who lack upper body strength or have puny arms. Years ago it was considered a luxury option mostly for elderly people who drove big Buicks, Cadillacs, Lincolns and Imperials. But today, everybody wants effortless steering, whether they drive an econocar or a three-ton SUV. Consequently, virtually all cars are now factory-equipped with power steering as standard equipment.

When high pressure fluid from the power steering pump enters a steering rack, it is routed through “spool valves” connected to the steering column. When the driver turns the steering wheel, the spool valves open ports that direct pressure to a hydraulic chamber around the rack. A piston on the rack bar divides the chamber into two halves, and pressure is channeled into one side or the other depending on which way the driver is turning. This provides power assist and helps push the rack bar in the desired direction.

Normal operating pressures within a power rack generally do not exceed 150 psi when the wheels are straight ahead. In a turn, pressure can climb to as much as 700 psi or higher depending on how much assist is needed. That’s why the seals must be leak-free.

WHEN TROUBLE STARTS
The first sign of leakage may be a telltale stain in the driveway. Or, the vehicle owner may notice the fluid inside the power steering pump reservoir keeps disappearing. If the fluid level gets too low, the pump may suck in air causing noise and a loss of power assist.

Normally, the power steering system should not use any fluid. The level should remain the same regardless of the age of the vehicle or how many miles on the odometer -unless, of course, the system is leaking.

Checking the power steering fluid reservoir regularly (as when changing oil or doing other underhood maintenance) is a good way to catch leaks early on before they cause additional problems. The level should always be checked any time a steering complaint is noted.

If the fluid level is low, a complete and thorough visual inspection of the entire power steering system should be undertaken to determine where the fluid is going.

Power racks typically leak at one or both ends where the rack bar passes through the end seals, at the pinion input shaft seal, and/or internally in the spool valve housing. Leaky end seals may or may not leave telltale stains on the outside of the rubber or plastic bellows. If the leak is really bad and the bellows are cracked or loose, you’ll probably see fluid dripping from the rack and the bellows will be wet. But if the bellows are still intact and tight, you might not see any obvious signs of leakage.

LEAK CHECKS
Normally, the end bellows on a steering rack should contain little or no power steering fluid. Their purpose is to protect the inner tie rod sockets from dust and moisture. A few teaspoons of fluid in the bellows of a high mileage vehicle is not unusual and is not a valid reason for replacing the seals or the rack. But if the bellows contain a lot of fluid, the rack is leaking and needs to be fixed.

On vehicles that have soft rubber bellows, you can pinch or squeeze the bellows to feel for fluid inside. On vehicles with hard plastic bellows, you’ll have to loosen the bellows clamp and slide the bellows back to check for fluid inside.

If you’re not sure the rack end seals are leaking, or you want to verify a leak before repairs are recommended, here’s another procedure you can use:

Raise the vehicle so the front wheels are off the ground.

Loosen and push back both bellows on the ends of the rack so you have a clear view of the seals on both ends of the rack.

Wipe off any dirt or oil on the rack bar.

Start the engine, and with it idling at approximately 1,000 rpm, crank the steering wheel all the way to the right stop and hold under light pressure for about five seconds. Do not hold the wheel so hard against the stop that it activates the pressure relief valve! Then crank the wheel all the way to the left and hold for five seconds. Repeat this 8 to 10 times.

Now check the rack for leaks. If you see fluid dripping from the rack, the end seals are leaking and repairs are needed. If no leaks are found at the end seals, check the pinion input shaft seal and the hoses and pump.

If a hose connection is leaking, you might be able to fix it by replacing the seals or O-rings. But don’t try to fix a leak by simply tightening the hose or line connection. On some racks (Ford, for example), there’s supposed to be some flex in the connections. If you try to stop a leak by overtightening the connection, you may end up stripping the threads.

INTERNAL LEAKS
If the seals around the spool valves inside the rack are leaking, the steering may feel stiff or sluggish especially when a cold vehicle is first started. This condition is often called “morning sickness” and has nothing to do with having a baby. But your customer may have a cow when you tell them they need a new rack and how much it’s going to cost!

New seals alone won’t fix most internal leaks because the old spool valve seals have usually worn grooves into the inside of the control valve housing. This tends to be more of a problem in racks with aluminum control valve housings than ones with cast iron control valve housings. The only cure for this kind of leak is to replace the rack with one that has a new or sleeved control valve housing.

RACK REPAIR OPTIONS
Replacing a set of leaky seals with new ones would seem to be the most logical and easiest way to repair a leaky steering rack. But seal kits are very hard to find, and often cost almost as much as a remanufactured rack. In researching this article, we called half a dozen auto parts stores to see if anybody carries seal kits for racks. None did.

One reason why auto parts stores don’t carry seal kits is that few shops attempt to rebuild racks themselves. High mileage racks usually have multiple problems, such as worn rack bars and gears. Corrosion or scratches on the rack bar will quickly ruin a new seal. Attempting to sand or polish out a rough spot on the bar only makes matters worse by creating a low spot that leaks even more when it slides back and forth under a seal. That’s why it’s faster, easier and less risky to simply replace a rack if it is leaking or worn.

A quality remanufactured rack should be pressure tested to assure it is leak-free, and come with a warranty to protect you in the event of a comeback.

HOSE LEAKS
If you find a leaky hose, or hoses that are cracked, rock hard with age, deteriorated and mushy feeling or otherwise damaged, replacement is the only cure.

Power steering systems have two types of hoses: a high pressure supply hose that carries pressurized fluid from the pump to the steering gear, and a return hose that routes low pressure fluid back to the pump reservoir. High pressure supply hoses are made from a reinforced material capable of withstanding high operating pressures (up to 1,300 psi) and high temperatures (250 to 300 degrees F). Return hoses, on the other hand, operate at much lower pressures (usually less than 50 psi). If a hose needs to be replaced, use the correct type for the application.

Sometimes rubber power steering hoses deteriorate internally. Small pieces of rubber flake loose and lodge in the valves within the pump or steering gear. This can cause the pump to work harder in an attempt to overcome the blockage, resulting in increased noise and steering effort. Old hoses should be replaced to prevent expensive pump and/or steering gear damage.

FLUID FLUSHES
When hoses, the rack or power steering pump are replaced, the entire system should always be flushed to remove all the old dirty fluid. Power steering fluid deteriorates over time, and accumulates contaminants that can damage newly installed parts. As the fluid ages, it’s viscosity increases which can increase steering effort when the fluid is cold. The fluid can also leave varnish deposits that can affect the operation of the pump and spool valves in the rack.

Some experts recommend changing the power steering fluid every 50,000 miles for preventive maintenance. This type of service can prolong the life of the power steering pump and rack as well as the internal seals.

Always use the type of power steering fluid specified by the vehicle manufacturer since fluid requirements vary from one vehicle to another. Using the wrong type of fluid may cause seal swelling and leakage and may void the warranty on a new or reman replacement rack.

OTHER RACK PROBLEMS
Of course, leaks aren’t the only problem that can afflict a steering rack. As the miles add up, the constant pounding, vibration and friction wears the inner tie rod sockets and increases play between the rack and pinion gears. Worn tie rod sockets will have the same effect as worn tie rod ends, creating play in the steering and causing a change in toe alignment that will accelerate tire wear.

Inner toe rod wear can also be checked by placing the wheels on the ground and having an assistant rock the steering back and forth while you look and feel for looseness in the linkage and sockets. With soft rubber bellows, you can pinch the bellows to feel the tie rod sockets inside. But with hard plastic bellows, you’ll have to slide the bellows back to see the sockets.

Center wear is another common problem that can afflict a high-mileage rack. Steering wears most in the straight ahead position because that’s the direction of travel most of the time. Wear between the pinion gear and rack teeth creates looseness that may contribute to steering wander and increased feedback (noise or harshness when hitting bumps, for example).

Most racks have a pinion preload adjustment. But if the adjustment is made with the rack in the centered, straight ahead position, it may cause the rack to bind when the steering is turned to either side. If you attempt to make an adjustment to compensate for wear, therefore, make sure the rack is steered to one side before tightening the adjustment nut. Also, make sure the steering turns lock to lock without binding after the adjustment has been made.

If the steering feels loose, you should also inspect the outer tie rod ends, steering input shaft coupling, rack mounts and front wheel bearings before adjusting or replacing anything.

NOISE
Some power steering systems are inherently noisy and there isn’t much you can do about it. A certain amount of hissing during normal low speed maneuvers is normal. But unusual noise usually means trouble.

The familiar high-pitched squeal or chirping that occurs when the steering wheel is cranked to one side or the other usually indicates a loose or oil-soaked belt. Check belt tension, and the automatic tensioner if the engine has a serpentine belt.

If the belt is soaked with oil, no amount of tightening will restore its grip. But don’t just replace the belt and consider the problem fixed. You also need to fix the oil leak, otherwise the replacement belt will suffer the same fate.

Buzzing noises are usually caused by a bad control valve in the pump. Replacing the valve may be all that’s necessary to eliminate the problem. But if the pump itself is whining, the pump shaft bearings are shot and it’s time to replace the pump.

Groaning noises can be caused by restrictions, low fluid level or air in the system.

Rattling usually indicates mechanical vibration. Check the pump mounting brackets on the engine, and for contact between the pressure hose and the chassis or other parts.

A growl may be the result of a restriction in the steering gear or hose, or the result of pump cam ring wear or a scarred pump pressure plate, thrust plate or rotor.

The following two tabs change content below.

Larry Carley

Larry Carley has more than 30 years of experience in the automotive aftermarket, including experience as an ASE-certified technician, and has won numerous awards for his articles. He has written 12 automotive-related books and developed automotive training software, available at www.carleysoftware.com.
  • Jeff

    My car steers easy at first but gets harder to steer as everything heats up. 98 oldsmobile intrigue 3.8 with 230,000 miles. I think it is leaking on the passenger side of the rack and it looks like the boot is ripped. It’s hard to tell if it’s leaking because there’s a small oil leak at a sensor by the oil filter which I haven’t figured out how to fix yet.
    Do I need to replace the rack?

    • bensatx

      I would say yes. My corvette had the same issue. Started leaking power steering fluid and actually caught fire!!!

  • Stephanie

    My boyfriend replaced the steering rack, tie rod ends, and the pump on my 99 Taurus. The hose he ordered didn’t fit so he didn’t replace any hoses. Now we are unable to remove all the air from the system. What could be wrong? When we turn on the car, all of the fluid is sucked into the reservoir. Then when the car turns off, it shoots out of the pump, by popping off the cap. Any ideas?

Latest articles from our other sites:

Timken Launches New Training Material Resources For Automotive Technicians


The Timken Company announces the launch of four new training videos and multiple TechTips focusing on light vehicles during Automotive Aftermarket Week. Timken will reveal all of its new technical training...More

Expanded Walker Direct-Fit Catalytic Converter Line Helping Shops Return To Emissions Segment

A growing number of automotive service providers that have historically outsourced catalytic converter replacement and other emissions control services are returning to the category due in part to the...More

Audi Engine Timing Chain Failure Due to Lack of Maintenance

If you’ve been working on cars as long as me, you’ll remember the first timing belt you did and thought, “what was wrong with timing chains?” It was only a year ago, when I was working on a 2005...More

Acura: Clunk Noise While Turning

Model: Acura RSX 2005-’06 Symptom: The front suspension makes a ­clunking noise while turning. Probable Cause: The front springs are moving on the spring seats. Corrective Action: Replace both...More

Rotary Lift To Showcase Updated Four-Post Car Lifts At SEMA Show 2014

Vehicle service professionals will have the first opportunity to see Rotary Lift’s updated 14,000-lb. capacity four-post general service and alignment lifts at the SEMA Show. The enhanced lifts will...More

Bendpak Breaks Ground On New Warehouse and Shipping Complex

    BendPak, Inc. announced the recent groundbreaking to celebrate beginning construction of a 67,000 square-foot multipurpose warehouse and shipping center located on 3.7 acres of...More

‘Green’ Bullets: Tips for Servicing Hybrid Vehicles

Newsflash: Hybrids are here to stay. The oldest Toyota Prius models are now 14 years old and many other hybrids from other manufacturers are crossing the 100,000-mile mark every day. Here are a few...More

Legendary Spark Plugs: The Six Toughest Vintage Spark Plug Replacements

1. AMC Pacer: The Pacer was supposed to get a GM Wankel rotary engine. If this were the case, the four plugs would have been easy to access. But thanks to emissions problems, the Pacer would get the regular...More