The Dangers of Mixing Oil with Your Car's Braking System

Brake fluid and lubricating oil, despite both being crucial for your car's operation, are fundamentally different and should never be mixed. If you accidentally mix them, it can lead to serious and potentially dangerous consequences. This article delves into the specifics of what happens when you mix brake fluid and lubricating oil, the risks involved, and the necessary steps to repair the damage.

The Composition of Brake Fluid and Lubricating Oil

Brake fluid is typically based on ethylene and propylene glycols, with additives to improve its stability, prevent corrosion, and ensure it absorbs water efficiently. On the other hand, lubricating oil, which comes from mineral oil derived from crude oil, consists of long-chain hydrocarbons that repel water. Mixing these two fluids can be hazardous due to their contrasting properties.

The Risks of Mixing Brake Fluid and Lubricating Oil

When brake fluid and lubricating oil are mixed, they do not easily blend together,-forming an emulsion instead. This emulsion reduces the ability of the lubricating oil to create a strong, protective film in areas where it is needed, such as bearing surfaces. Furthermore, the absorbent nature of brake fluid attracts water, which, when present in the lubricating oil, can cause corrosion and pitting of the surfaces it contacts. This can lead to scoring of bearing journals, severe mechanical wear, and ultimately, a compromised braking system.

Damage to Automotive Components

Mixing brake fluid with lubricating oil can also result in significant damage to the rubber and synthetic seals within the hydraulic system. These components are specifically designed to work with brake fluid and do not stand up well to other oils. Rubber expands and dissolves when exposed to brake fluid, leading to swelling and eventual failure of the seals. This can result in fluid leakage, which further exacerbates the problem.

Repairing the Damage

The steps to repair the damage caused by mixing brake fluid and lubricating oil are extensive and require utmost care to ensure the safety of the vehicle:

Replace Rubber Components: Replace any rubber components that have been exposed to brake fluid. This includes: Master cylinder Front calipers Rear wheel cylinders or calipers Brake hoses ABS hydraulic unit Steel brake lines Proper Cleaning: Use a shop to suction out the brake fluid from the master cylinder reservoir. Then, flush the brake hydraulic system completely and refill it with new brake fluid. Rebuild or Replace: If necessary, rebuild or replace the components that have been damaged. Seal Assessment: Inspect and replace all seals and gaskets.

Conclusion

In summary, the consequences of mixing brake fluid and lubricating oil are severe and can jeopardize the safety and performance of your vehicle. If you find yourself in such a situation, it is crucial to address the issue immediately and seek professional assistance. Never use regular motor oil as a substitute for brake fluid in a pinch, as it can lead to overheating and reduced braking efficiency. With proper diagnosis and repair, your vehicle can regain its optimal performance and keep you safe on the road.