What Causes Power Steering Failure

Power steering typically fails because of fluid leaks, worn or broken pumps or belts in hydraulic systems, or sensor, motor, wiring, or low-voltage issues in electric systems. In practice, problems range from simple—like low fluid or a slipping belt—to complex faults such as a failing steering rack, torque sensor errors, or a control-module fault. Understanding which type of system your vehicle uses—hydraulic, electric, or electro-hydraulic—helps pinpoint the cause and the safest next steps.

How Power Steering Works

Most cars built over the last decade use electric power steering (EPS), which relies on a motor, sensors, and software. Older models commonly use hydraulic power steering (HPS), driven by a pump moved by the engine via a belt and using pressurized fluid to assist steering. Some vehicles use electro-hydraulic systems that blend both approaches. Failures usually stem from fluid, pressure, or mechanical issues in HPS and from electrical, electronic, or voltage issues in EPS.

Common Causes by System Type

Hydraulic Power Steering (HPS)

The following list outlines the most frequent reasons hydraulic systems lose assist or fail outright.

• Fluid leaks: Cracked hoses, loose clamps, failing rack seals, or a leaking pump shaft seal lead to low fluid and loss of pressure.
• Worn or failing pump: Internal wear, seized bearings, or a stuck pressure relief valve reduce or stop hydraulic pressure.
• Drive belt or pulley problems: A loose, glazed, or broken belt (or bad tensioner/idler pulley) prevents the pump from spinning properly.
• Contaminated or incorrect fluid: Debris, moisture, or the wrong specification (e.g., mixing ATF with a specialty CHF fluid) damages pumps and racks.
• Clogged filters or lines: A clogged reservoir screen or narrowed lines cause cavitation and whining noises with weak assist.
• Air in the system: Entrained air from a recent repair or leak creates foaming, noise, and erratic assist.
• Rack-and-pinion wear: Internal wear or bent rack components cause hard steering, notchy feel, or one-direction assist loss.
• Cold-weather thickening: Old fluid thickens in low temperatures, delaying or reducing assist until warm.

Because HPS relies on clean fluid and steady pressure, even minor leaks or contamination can cascade into pump and rack damage if not addressed quickly.

Electric Power Steering (EPS)

Electric systems fail for different reasons, often related to power supply, sensors, or control modules rather than fluid and pressure.

• Low battery or charging issues: Weak batteries or failing alternators drop system voltage, causing intermittent or total loss of assist and warning lights.
• Steering torque/angle sensor faults: Sensor failure or miscalibration disrupts the assist calculations, triggering EPS warnings and heavy steering.
• Motor or control module failure: Overheating, worn brushes/bearings (in some designs), or internal electronic faults cut assist.
• Wiring, grounds, fuses, or relays: Corroded connectors, chafed harnesses, blown fuses, or bad relays interrupt power or signals.
• Software/communication errors: Outdated software, CAN bus faults, or module misconfiguration can disable assist until reprogrammed or repaired.
• Water intrusion or corrosion: Moisture entering the column/gear housing or connectors leads to intermittent assist and eventual failure.
• Overheat protection: During prolonged full-lock turns or high-load maneuvers, some systems briefly cut assist to protect the motor.

Because EPS depends on stable voltage and clean signals, many failures are intermittent at first—appearing as a steering warning lamp, brief heaviness, or assist that returns after a restart.

Universal Triggers and Contributing Factors

Some issues can affect any power steering setup, regardless of type.

• Front-end binding: Seized strut top bearings or steering shaft U-joints make steering heavy and can mimic or worsen assist failures.
• Alignment or suspension damage: Bent components increase steering effort and stress the assist system.
• Accident or curb impact: Impacts can damage racks, subframes, sensors, or wiring.
• Poor maintenance: Ignored fluid, worn belts, and neglected electrical grounds accelerate failures.
• Extreme temperatures: Heat degrades fluid and electronics; deep cold thickens fluid and stresses components.
• Aftermarket modifications: Incorrect wheels/tires or altered electrical systems can overload steering components or reduce available voltage.

Addressing these contributing factors often prevents small issues from turning into full system failures.

Warning Signs You May Notice

Recognizing early symptoms can prevent an inconvenient or unsafe loss of assist.

• Heavy steering or intermittent assist, especially at low speeds or when parking.
• Whining, groaning, or squealing noises when turning the wheel.
• Power steering or EPS warning light on the dashboard.
• Fluid puddles under the car; low, dark, or foamy fluid in the reservoir (HPS).
• Burning smell or belt squeal with steering input (HPS).
• Notchy feel, kickback, or steering that doesn’t self-center smoothly.

If these symptoms appear, stop aggressive maneuvers and investigate before the system fails completely.

How to Diagnose the Problem

A structured approach—starting with basics and moving to targeted tests—saves time and money.

1. Identify your system type: Hydraulic, electric, or electro-hydraulic (owner’s manual or service info).
2. Check for warnings: Note any steering/EPS lights and messages.
3. Scan for codes: Use an OBD-II scanner that reads chassis/steering modules; record and research DTCs.
4. Verify power/ground: Measure battery voltage (aim for ~12.6V off, 13.8–14.7V running) and inspect grounds and fuses.
5. Inspect fluid (HPS): Check level, color, and smell; top up only with the specified fluid and look for leaks.
6. Inspect belt and pulleys (HPS): Look for cracks, glazing, slack, or noisy tensioners/idlers.
7. Mechanical checks: Turn wheels off the ground; feel for binding in strut bearings, ball joints, or steering shaft U-joints.
8. Pressure/flow test (HPS): A shop can test pump output and rack pressure to isolate pump vs. rack faults.
9. Sensor calibration (EPS): Perform steering-angle and torque sensor resets after alignment or repairs.
10. Review TSBs: Check for technical service bulletins or software updates for your model.

Documented fault codes and simple visual checks often lead directly to the root cause without guesswork.

Quick Checks You Can Do at Home

These basic checks can quickly reveal common problems before a shop visit.

• Look for leaks: Inspect under the car and around the pump, hoses, and rack boots (HPS).
• Listen while turning: Whine = low fluid/cavitation; squeal = slipping belt (HPS); clicking or relay chatter may indicate EPS electrical issues.
• Battery health: If cranking is slow or lights dim at idle, test or charge the battery; poor voltage often triggers EPS faults.
• Top up with correct fluid: Only use the exact spec in the manual; never mix types. Bleed air by turning wheel lock-to-lock with the front lifted (HPS).
• Soft reset: For EPS, a key-off wait and restart may temporarily restore assist if voltage or software glitches are the cause—still diagnose properly.

If these checks resolve the symptom temporarily, schedule proper service to prevent recurrence or secondary damage.

When It’s Unsafe to Drive

Power steering failure can dramatically increase stopping distance and steering effort, especially at low speeds.

• Steering effort is excessive or the wheel won’t return toward center.
• Assist is intermittent in traffic or during parking maneuvers.
• You see rapid fluid loss or hear loud grinding/whining with metal flakes in fluid (HPS).
• EPS warning with heavy steering after a charging-system failure.

When in doubt, pull over safely and consider towing—forcing the system can cause further damage or loss of control.

Prevention and Maintenance

Regular care reduces the risk of sudden failure and extends component life.

• Inspect fluid annually (HPS) and change proactively every 50,000–100,000 miles if not otherwise specified.
• Use only OEM-specified fluid; some systems require specialty CHF fluids, not ATF.
• Check belts, tensioners, and pulleys at each service (HPS).
• Avoid holding the wheel at full lock for more than a few seconds; it stresses pumps and EPS motors.
• Protect electronics: Keep splash shields in place and repair corroded grounds/connectors (EPS).
• Maintain the battery and alternator; EPS needs stable voltage.
• Address suspension and alignment issues promptly to reduce steering load.

Preventive steps are inexpensive compared to racks, pumps, or EPS motor/module replacements.

Typical Repair Costs and Time

Costs vary by vehicle, parts quality, and labor rates, but these ranges provide a general guide.

• Pump replacement (HPS): $300–$800 parts plus labor; 1.5–3.0 hours.
• Rack-and-pinion (HPS/EPS gear): $800–$2,000+ installed; 3–6 hours plus alignment.
• Hoses/lines (HPS): $100–$400 each; 0.5–2.0 hours.
• Reservoir/filter (HPS): $100–$250; 0.5–1.0 hour.
• Fluid flush/bleed (HPS): $80–$150.
• Belt/tensioner (HPS): $75–$200 parts; 0.5–1.5 hours.
• Torque/angle sensor (EPS): $100–$400 parts; 1–3 hours plus calibration.
• EPS motor or control module: $400–$1,500+ parts; 1–4 hours plus programming.
• Battery/alternator (EPS-related): $300–$900 installed.
• Alignment after steering work: $100–$250.

Obtaining a diagnostic estimate first is wise; accurate fault isolation avoids replacing good parts.

Summary

Power steering failures usually trace to fluid and pressure problems in hydraulic systems—leaks, worn pumps, bad belts—or to electrical, sensor, voltage, and control issues in electric systems. Early symptoms include heavy steering, noise, warning lights, and visible leaks. Confirm your system type, scan for codes, check voltage and fluid, and inspect belts and wiring. Timely maintenance, correct fluids, solid electrical health, and prompt repairs are the best defenses against sudden loss of steering assist.

How do you fix power steering failure?

Check the Power Steering Fluid Level
Unscrew the cap of the power steering pump and check the fluid level. If it’s not full, buy power steering fluid from your local automotive supply store and refill the pump. If you have to add power steering fluid frequently, you may have a leak in your car’s steering system.

Can you drive a car with power steering problems?

Yes, you can typically drive a vehicle if the power steering goes out, but it will require significantly more physical effort to steer, especially at low speeds or when parking. Driving without power steering is generally safe for short distances to a mechanic if you are careful, but it can be dangerous if you can’t steer quickly enough in an emergency. You should drive cautiously, using both hands on the wheel, and get the system repaired as soon as possible to avoid further damage to the power steering pump and other components. 
What happens when power steering fails?

• Heavier Steering: The system provides hydraulic assistance, so without it, turning the wheel becomes much harder. 
• Increased Difficulty at Low Speeds: You’ll find it especially challenging to turn the wheel when the car is stopped or moving slowly. 
• Potential for Damage: Driving without fluid can cause the pump to overheat and fail, and the belt that powers the pump can snap. 
• Danger in Emergencies: It can be difficult to react quickly enough during an emergency, making it more likely to cause an accident. 

What to do if your power steering fails:

1. Park Safely: Pull over to a safe location on the side of the road as soon as possible. 
2. Assess the Steering: Turn the wheel to see how much effort it takes. 
3. Check Fluid (if applicable): For hydraulic systems, check if the power steering fluid is low and add the correct type if needed. 
4. Drive Cautiously: If it’s manageable, drive slowly and carefully to the nearest mechanic. 
5. Use Both Hands: Grip the steering wheel firmly with both hands to maintain control. 
6. Avoid Sharp Turns: Be prepared for the increased effort needed for sharp or sudden turns. 
7. Call a Tow Truck: If you feel you cannot accurately steer the vehicle, it’s safer to call for a tow truck. 

Get it fixed: 

• Repair ASAP: Get your vehicle to a qualified mechanic as soon as possible to prevent further damage to the system.
• Consult a Professional: A mechanic can diagnose the issue and provide an accurate estimate for repairs.

What is the most common problem in a steering system?

Here are some of the most common:

• Fluid Leakage: Power steering relies on steering fluid (remember a steering is essentially a hydraulic system) to help transmit force to the wheels.
• Worn Out Power Steering Pump: The power steering pump pressurizes the steering fluid and sends it to the steering gear.

Is it expensive to fix power steering?

Yes, fixing a power steering issue can be expensive, with costs ranging from under $100 for a simple fluid flush to $800 or more for a new power steering pump, and even higher for complex repairs like a steering rack replacement. The final cost depends on the specific problem, your vehicle’s make and model, the parts used (OEM vs. aftermarket), and your location. 
Breakdown of Common Repairs and Costs

• Power Steering Fluid Flush: Opens in new tabIf the issue is dirty fluid, this can resolve the problem for approximately $50 to $150. 
• Power Steering Pump Replacement: Opens in new tabThis is one of the more expensive repairs, with average costs ranging from $500 to $900, though it can go higher for luxury or large vehicles. 
• Power Steering Hose Replacement: Opens in new tabA leaking hose is generally a less expensive repair, potentially costing around $60 to $150, depending on the specific hose and labor involved. 
• Steering Rack Replacement: Opens in new tabThis is a significant and expensive repair, with parts and labor for a steering rack replacement costing several hundred dollars. 

Factors Affecting Cost

• Vehicle Make and Model: Luxury cars and larger vehicles typically have more expensive parts and labor. 
• Part Type: Using an Original Equipment Manufacturer (OEM) part from your car’s manufacturer is usually more expensive than an aftermarket part. 
• Labor Costs: The hourly rate for mechanics varies by location and shop. 
• DIY vs. Professional Repair: If you are comfortable with car maintenance, you can save money by doing some repairs yourself, but it’s important to ensure you have the right tools and knowledge. 
• Additional Repairs: Power steering issues can sometimes lead to other necessary repairs, such as a wheel alignment after a steering rack replacement.