Power Steering Fluids: How to Choose and Change Them Correctly?

Typically, the lifespan of the entire power steering assembly with hydraulic assistance is comparable to the overall longevity of the car. However, this assumes that the system doesn't develop leaks in the power steering fluid. The use of low-quality or incompatible oil, or premature oil changes, are among the most common causes of power steering failure with hydraulic assistance.

Read our article to learn how to avoid these mistakes and choose the right hydraulic fluid, as well as how to change it in a timely manner.

Reasons for Deterioration of Power Steering Fluid Quality

Intense loads on power steering with hydraulic assistance and sudden drops in system pressure lead to early degradation of the oil. Technical specialists cite four main reasons for the deterioration of fluid condition:

• System Overheating: Excessive heat in the system.
• Aggressive Driving Style: Excessive use of power steering with hydraulic assistance.
• System Integrity Damage: Physical damage to the system and compromise of its seal.
• Use of Inappropriate Fluid: Use of power steering fluid that does not meet the technical requirements of the specific vehicle.

Modern cars use special valves to protect power steering system components from damage.

When You Need to Replace Power Steering Fluid

Most car manufacturers, including MITSUBISHI, VOLKSWAGEN, and FORD, recommend changing power steering fluid every 1-2 years or every 100,000 kilometers. Unplanned oil replacement is necessary if you observe the following signs:

• Color Change: The oil becomes dark.
• Burning Smell: A smell of burning.
• Increased Steering Resistance: More effort required to turn the steering wheel.
• Unusual Noise: Abnormal noise when turning the steering wheel.
• Fluid Leakage: Visible leakage of fluid.

You should also replace power steering fluid if repairs or replacement of the power steering pump or any other power steering system components have been performed. The use of oil that has lost its initial properties can damage the pump and other parts of the power steering system, leading to premature wear of seals.

For some cars, such as TOYOTA Corolla, SUBARU Impreza, and almost all VOLKSWAGEN cars, if the seals fail and the integrity is compromised, it may be necessary to install an entirely new power steering unit.

How to Choose Power Steering Fluid

There are basic types of power steering fluids:

• Mineral: Refined petroleum fractions with additives to improve oil properties. The main advantage is their non-aggressive impact on rubber components. However, they have a short service life and tend to foam.
• Semi-Synthetic: Their composition includes both mineral and synthetic substances. Advantages include low viscosity, resistance to foaming, and good lubricating properties. However, semi-synthetic fluids have a destructive effect on rubber components.
• Synthetic: Primarily composed of polyatomic alcohols, complex polyethers, and a small amount of partially refined oil. Special additives are used to reduce the destructive impact on rubber seals. Synthetic oils, although more expensive, have excellent operational characteristics: resistance to foaming, the ability to work at extreme temperatures, and a long service life.

Power steering fluid usually has information on the package about the standards it complies with and indications of which automotive brands' products it can be used in.

Hydraulic Fluid for Power Steering: Types and DIY Replacement

Hydraulic fluid for power steering is classified not only by composition and characteristics but also by color. The most common colors include:

• Red

Manufactured to GM Automotive Group standards, also known as Dexron. Produced by the company itself and licensed manufacturers. Used in TOYOTA, KIA, MAZDA, and GM vehicles.

• Yellow

Primarily designed for MERCEDES-BENZ cars. Developed by Daimler but also produced by other licensed manufacturers.

• Green

Produced by the German company Pentosin. Mainly used in VOLKSWAGEN, FORD, BENTLEY, BMW, and VOLVO vehicles, as well as in Daimler Group cars.

However, choosing power steering fluid based solely on color can be misleading. The color does not always indicate the composition. For example, Dexron fluids can be either mineral or synthetic, even though they share the same color. Mixing mineral, synthetic, and semi-synthetic power steering fluids is strictly prohibited.

DIY Power Steering Fluid Replacement

Anyone can independently replace the fluid in the power steering system. This process is simple and takes only about 30 minutes. For this procedure, you'll need a large syringe, an old container for the fluid, and protective gloves.

Follow these steps:

• Lift the front of the car using a jack and secure it.
• Using a syringe and pump, drain the old fluid from the reservoir.
• Disconnect the return hose and place it in the prepared container, then drain the oil.
• Pour new fluid into the system.
• Turn the steering wheel until it stops several times.
• If the old fluid is still draining, pour in new fluid until it reaches the mark on the power steering fluid reservoir or the measuring dipstick attached to the reservoir cap. Continue pouring until the new fluid starts coming out of the hose.
• Return the hose to its original position, start the engine, and turn the steering wheel in both directions.
• Top up the fluid to the mark.

Conclusion: Purchase only high-quality power steering fluid, always pay attention to the technical requirements of your car, and do not neglect oil change recommendations. A calm driving style, timely fluid replacement, and adherence to recommended guidelines will ensure a long and reliable operation of power steering with hydraulic assistance.