Finding discolored fluid in any component of your vehicle is worrisome. Discolored fluid can be a frustrating problem because you may not know what is causing the discoloration and because it looks harmful. Indeed, brown or black power steering fluid is never a good sign and should be addressed quickly.
How this system works:
Power steering fluid is a necessary part of your vehicle’s power steering system. The fluid is pumped from the reservoir to the wheels by the power steering pump. Near the wheels the power steering fluid applies pressure to a piston inside the rack and pinion, which is connected to the wheels. This pressure gives the wheels the strength needed to turn and makes a vehicle dramatically easier to steer.
When the fluid becomes contaminated, the entire power steering system can be damaged. The dark colored power steering fluid can clog the power steering pump hoses and damage the bearings in the system.
Brown or black power steering fluid is not a death sentence for your vehicle but it is an issue that should be handled promptly. You can continue to drive your vehicle however, it is best to make an appointment with a mechanic as soon as possible.
Common reasons for this to happen:
- Contaminated with Aluminum: As your power steering fluid does its job, it comes into frequent contact with your vehicle’s rack and pinion. The rack and pinion system is made up of high amounts of aluminum which over time can shed into a fine powdered state. This fine powder can contaminate your power steering fluid resulting in a sludgy compound that does not hold the same consistency as your ideal power steering fluid.
This shedding of aluminum particles is natural, so you usually don’t need to be concerned with the status of your car’s rack and pinion. However, after having your steering fluid replaced, you should check its color with regularity. If the fluid returns to a dark color quickly, then the rack and pinion should be inspected.
Water In System: Water causes power steering fluid to oxidize, which diminishes the ability of the fluid and therefore of the system as a whole. As with many components of your vehicle, the power steering fluid reservoir can sometimes trap unwanted water. This water mixes with the fluid, causes oxidization and changes the color of the power steering fluid.
Fluid Degradation: Power steering fluid is subject to high loads of pressure, as it relies on pressure to do its job effectively. This pressure causes the temperature of the fluid to increase, especially during long drives. As the fluid rises in temperature, it begins to slowly break down as the chemicals separate from one another. This is known as electrochemical degradation and is the cause of discoloration and sludge in the power steering fluid.
What to expect:
A top-rated mobile mechanic will come to your home or office to determine the cause of the brown or black power steering fluid, and will then provide a detailed inspection report that includes the scope and cost of the necessary repairs.
How it's done:
Discolored power steering fluid cannot be reversed. Instead, the fluid needs to be drained from the power steering system and replaced with fresh fluid. This is called a power steering fluid flush. A mechanic will disconnect the power steering hose from the power steering pump and drain all of the fluid out of the system. After reconnecting the hose to the pump, a fresh batch of clean power steering fluid will be added to the reservoir. Once the system has been flushed, the mechanic will usually turn on your vehicle and turn the steering wheel a few times to introduce the new fluid to the system. This process will also allow your mechanic to identify any other issue that may require his or her attention.
How important is this service?
When your power steering becomes discolored, it runs the risk of harming the rest of your power steering system. It’s important that you schedule an inspection as soon as you notice that your power steering fluid is brown or black, so that you don’t cause severe damage to the system.