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Diagnosing Power Steering Leaks in Idle Cars: Causes, Consequences, and Cures

Leaky power steering pump

If you notice a puddle of oil under your car while it is off, it could be coming from the car’s power steering system.

When the car is off with a non-pressurized power steering system, the power steering system is less likely to leak than when the car is running with a pressurized power steering system.

However, a brittle and cracked power steering reservoir or worn power steering seals and power steering hoses could still leak in a non-pressurized system.

Below we'll go over the causes, symptoms, solutions, and costs of a car that leaks power steering fluid while it is off.

Table Of Contents [show]

    Power steering pump leaking oil
    Power steering pump leaking oil

    What Causes A Power Steering Fluid Leak When The Car Is Off?

    There are many reasons why your car may be leaking power steering fluid while off, depending on the symptoms:

    Leaking Power Steering Pump

    Hydraulic power steering pumps are working continuously while the vehicle is running and are subject to wear and tear; and eventual replacement.

    Replacing the entire pump is a relatively involved and complex process, and unless you are ambitious and have the proper tools, it's best left to a professional.

    Bad Power Steering Wheel Fluid

    Occasionally, sometimes by mistake, owners will use the wrong type of power steering fluid in the system.

    Different vehicle models require different types of power steering fluids depending on their designs.

    The most common types are conventional fluids and the newer silicone-based steering fluids.

    In many cases, mixing incompatible fluids or putting the wrong fluid into the system will damage hoses, seals, and the pump, leading to the need for complete system replacement.

    If unsure, check the vehicle's owner's manual for the required power steering fluid.

    Also, power steering fluid degrades over time due to particle and moisture contamination so be sure to check the recommended power steering fluid service interval with your mechanic or owner's manual.

    Power Steering Hoses And Seals

    The hoses and seals on the average power steering system are designed to last incredibly long and stand up to very high pressures and harsh conditions.

    That said, if a line, hose, or seal is installed incorrectly or worn, it can cause premature failure. Also, environmental stresses of season changes, temperature fluctuation, and corrosion will often cause seals to begin to leak after a while.

    Usually, seals are the most common component to degrade.

    Although most often replaceable, they require the appropriate tools.

    Incorrect Quantity Of Power Steering Fluid

    Common causes of power steering fluid leaks are that sometimes there is just too much of it in the system.

    Power steering fluid reservoirs will have a "Low" mark and a "Full" mark, and paying attention to the fluid level is essential.

    Too little fluid in the system, and you could see decreased steering system performance due to under pressurization or premature component failure.

    However, filling past the "Full" mark puts too much fluid in the system, and too much fluid can result in too much pressure once the engine is running, which can force excess fluid to leak out.

    Power steering reservoir
    Power steering reservoir

    Power Steering Fluid Reservoir Is Leaking

    It's not uncommon for the power steering fluid reservoir to leak.

    Power steering reservoirs, often made of plastic, are located in the engine compartment, where they become brittle and may crack due to the elements, temperature changes from the warm engine, and age.

    Power Steering Fluid Leaking From Boot

    Each power steering pump has a main seal, often called the boot, where it connects to the first exterior component of your steering system, usually a gearbox.

    If this seal is damaged or has even a slight gap in its tolerances, it can result in a fluid leak that can range from minor to catastrophic.

    In most cases, you cannot repair this seal without completely rebuilding the pump.

    Since the work to rebuild the pump is often more intensive than simply replacing the pump, replacement is the most frequent solution.

    Symptoms Of A Steering Fluid Leak When The Car Is Off

    So, when it comes down to it, how do you know your car is leaking power steering fluid while it is off?

    You'll know because there might be visual evidence, but changes in how your car steers will also be likely.

    Here are the three most common symptoms you'll likely see if you have a steering fluid leak while your car is off.

    Steering Is Heavy At Low Speeds

    Your power steering pump is driven by the serpentine belt, which rotates along with the engine RPMs.

    At higher speeds, the pulley rotates relatively quickly, and you may not notice any difference in steering ability.

    At lower speeds, however, there may be a noticeable decrease in turning ability.

    In addition, the steering wheel may feel stiff, or it may take significantly more effort to tun since there will be lower pressure in the steering system.

    Lower steering ability will be the most obvious in places like parking lots.

    Steering is difficult with malfunctioning power steering
    Steering is difficult with malfunctioning power steering

    When Rotating The Steering Wheel, There Is A Whining Noise.

    Power steering fluid serves a dual function in the power steering system.

    The primary function is to provide a fluid that the power steering pump can put under hydraulic pressure to move the steering components.

    The secondary function is that it also serves to lubricate the entire power steering system as it circulates under pressure.

    When the fluid leaks, the pump may not receive the optimal amount of lubrication.

    A low fluid level often results in a whining or grinding noise when the steering wheel is turned while the car is on.

    The low fluid level will also contribute to accelerated wear and damage to the power steering pump and other components.

    Leaking Steering Fluid Onto The Engine Or The Street.

    One of the most obvious signs of power steering fluid leaking while the car is off is seeing fluid left on the street.

    However, if the fluid is leaking while the car is off, there may not be a large enough amount of fluid leaking to notice it before you drive off.

    Chances are, if this much fluid is leaking while you're parked, you likely have a significant leak and will also be noticing other symptoms.

    The best way to determine if your car is leaking power steering fluid while it's off is to examine where you park your vehicle daily or each night.

    You will want to look in the area where the front of your car generally is and look for a place where the fluid drips have discolored the pavement over time.

    You might see this in your driveway or the street where you usually park.

    Power steering leaking on the ground
    Power steering leaking on the ground

    What Does Power Steering Fluid Look Like When It Leaks

    Power steering fluid can be different colors, depending on the type of fluid your car needs.

    Sometimes, it may be pink or red, similar to transmission fluid.

    Other types will be relatively clear or amber-colored.

    It's important to note where the fluid is seen, as it can help diagnose where the leak is.

    A leak from the pump's main seal will continually drip in the same spot.

    Leaks from a hose or fluid line may result in the fluid dripping onto other components first, then down onto the ground, leaving a more dispersed leak pattern on the surface where the drips land.

    How Do You Repair A Power Steering Fluid Leak?

    Fixing your power steering fluid leak will depend on a few things.

    It will depend on why the fluid is leaking in the first place and where the leak is located.

    Debris In Power Steering System

    Sometimes, the power steering system will accumulate debris, which can cause uneven pressure resulting in leaks. A power steering system flush will be required in this case.

    Small Leaks

    You can sometimes fix small holes or dried-out seals by plugging the holes or rehydrating and expanding the seals.

    You can do this by using one of the many stop-leak products for power steering systems.

    These products seep into the tiny gaps causing the leak and harden in place, so the leak stops.

    Generally, you add the stop-leak to your power steering fluid reservoir.

    Worn Or Damaged Parts

    Another potential reason for a power steering fluid leak is worn out or damaged parts.

    Situations like these require that the parts be adjusted, tightened, or replaced to stop the leak.

    Loose Fittings

    Check the system for loose connections or broken parts, and tighten or replace as needed.

    Newly installed power steering pump
    Newly installed power steering pump

    How Much Does It Usually Cost To Fix A Power Steering Leak

    The cost to fix a power steering leak can range from quite manageable to relatively significant.

    Power steering stop-leak products can be a cheap and easy fix if the leak is due to a minor cause like a dried & shrunken seal or a tiny pinhole in the pump or hoses. If this is the solution you need, you can fix the issue for less than $10 in most cases.

    The repair may be more expensive if the leak is due to cracked or split hoses. This might be the case if you had a hose go bad and had it fixed by someone who wasn't exactly qualified or experienced in their installation.

    Hoses or power steering lines replaced by a professional may cost closer to $100 or more.

    In the worst-case scenario where the pump has failed, or one of the primary seals on the pump has become damaged, the entire power steering pump will need to be replaced.

    In this case, your repair cost will include the new pump's cost and the installation labor cost. This can cost several hundred dollars and is the most expensive potential solution.

    Wrap Up

    Although a power steering leak is less likely when a car is off versus running, it is still possible.

    There are places to look for a leak on the power steering housing, the hoses entering and exiting the power steering housing, and the power steering reservoir.


    Does Power Steering Fluid Stop Leak Work

    Power steering stop leak does work in certain situations. It is only made to stop leaks through tiny holes or gaps. If you have a significant leak, stop-leak may not be ideal.

    Losing Power Steering Fluid But No Leak

    If the leak is small, it may be hard to find. You'll need to take your vehicle to a mechanic to diagnose the problem.

    Friction and heat may burn off the fluid in rare cases where the power steering pump has an internal malfunction.

    How Do I Know If My Power Steering Pump Or Rack Is Bad?

    The symptoms of a pump going bad versus mechanical problems with other steering components will often depend on the symptoms.

    As you've read here, a pump will give a whine or even a squeal when it's operated by turning the wheel.

    Rack issues often lead to grinding, popping, or clunking noises.