As a driver, you know that your vehicle’s braking system is one of the most critical components for your safety on the road. With time and use, various elements in the braking system can degrade and in this case, it is the issue of moisture presence in the braking fluid. Moisture in brake fluid is a serious concern that can jeopardize your vehicle’s safety and performance.
Given that, most brake fluids are hygroscopic, meaning they naturally absorbs moisture from the atmosphere over time. Therefore, it is important for every vehicle owner to periodically check their brake fluid for moisture content because, even a small percentage of water in brake fluid can lead to several issues such as:
Reduced Boiling Point: Brake fluid’s boiling point decreases with increased moisture content, which can cause the brakes fade during heavy braking.
Corrosion: Water in the braking system can lead to corrosion of metal components, such as calipers, master cylinder and brake lines.
Brake Failure: In severe cases, moisture can cause total brake failure, putting both the driver and passengers at risk.
Signs of Moisture Presence in Brake Fluid
“Moisture in the brake fluid is a serious problem as it can significantly affect the performance of the braking system,” recalls the Managing Director and Founder of Duran Lubricants & Chemicals GmbH – producer of the brand FOSSER Motor Oil from Germany, Mrs. Ilona WILMS. However, you may be wondering how to identify moisture presence in brake fluid. Here are a few key signs to look for:
Discoloration: If you notice that your brake fluid has turned dark or cloudy, this signals moisture contamination. “Fresh brake fluid usually has a clear or slightly golden colour. If it becomes cloudy or dark in colour, this may indicate contamination or high water absorption,” notes Mrs. Wilms. The presence of moisture often looks like small particles or a milky appearance in the fluid.
Brake Performance Issues: If you feel that your brake pedal is spongy or requires more pressure to engage, it may signal that moisture is present in the brake fluid. When brakes are compromised due to moisture, they may fail to respond effectively, leading to potentially dangerous situations.
Boiling point test: “A precise method of checking is the boiling point test, in which the boiling point of the brake fluid is measured,” affirms Mrs. Wilms. “Moisture reduces the boiling point and if it falls below the recommended values (e.g. 230 °C for DOT 4), replacement is required,” she adds.
“Moisture in brake fluid is a critical safety issue that can compromise braking performance. To detect moisture, regular brake fluid testing is essential,” says Julien FAKHREDDINE, Regional Sales Manager of Middle East and Africa at Wolfoil Corporation. “Moisture tends to lower the boiling point of brake fluid, which can result in brake fade or failure under high-stress conditions. Brake fluid testers, which measure the fluid’s boiling point, can easily determine if water contamination is present,” he adds.
Unusual Odors: Any burnt or acrid smell emitting from the brake fluid reservoir can indicate overheating caused by excessive moisture contaminant. This requires immediate investigation.
Bubble formation: “If bubbles or foam are visible on the surface of the brake fluid, this indicates a reduction in boiling point properties, which may be caused by water absorption,” Interprets Mrs. Wilms.
Steps to Detect Moisture Presence in Brake Fluid
To confirm whether moisture is present in your brake fluid, follow these steps:
Step 1: Gather Necessary Tools
You will need the brake fluid tester, safety glasses, gloves and a clean rag or paper towels to test your brake fluid for moisture.
Step 2: Locate the Brake Fluid Reservoir
Begin by locating your vehicle’s brake fluid reservoir situated near the back of the engine bay, close to the driver’s side. Make sure to consult your owner’s manual for specific details about your vehicle’s brake system.
Step 3: Inspect the Brake Fluid
Wipe away any dust or debris from around the reservoir cap before opening it. Carefully open the brake fluid reservoir. Using your eyes first, check the color and clarity of the brake fluid. Look for any discoloration, cloudiness or foreign particles. If the fluid appears clear and yellow, the fluid is likely in good shape. However, if it exhibits signs of contamination, proceed to the next step.
Step 4: Use a Brake Fluid Tester
As Mrs. Wilms warns, “If high water absorption or significant colour changes are suspected, it is advisable to consult a specialist who can test the brake fluid and replace it completely if necessary.”
Even so, to accurately measure the moisture level in your brake fluid, utilize a brake fluid tester:
Insert the probe of the hygrometer into the brake fluid.
Wait for a few seconds for the tester to provide a reading.
Most testers will indicate the moisture content as a percentage. Aim for a moisture level below 2%. Levels above this indicate excessive moisture presence and warrant replacement of the brake fluid.
Step 5: Take Action if Moisture Is Detected
If you detect moisture levels above the recommended threshold:
Replace the Brake Fluid: It is advisable to replace the brake fluid entirely. You can do this yourself or seek professional assistance if you are not comfortable doing it. As Fakhreddine recommends, “When moisture is detected, the appropriate action is to flush and replace the brake fluid. It’s advisable to follow the manufacturer’s recommended intervals for brake fluid replacement to prevent moisture buildup. Regular checks and timely fluid replacement are key to maintaining optimal braking performance and vehicle safety.”
Correspondingly, Mrs. Wilms complements that, “The brake fluid should be changed regularly in accordance with the manufacturer’s instructions, usually every 1-2 years. This reduces the risk of moisture and ensures optimum braking performance.”
Inspect the Brake System: Pay attention to the entire braking system for any signs of leaks or corrosion. If you suspect any component has been compromised, have it inspected by a qualified mechanic. Stressing on the braking system inspection, Mrs. Wilms adds that, “If signs of moisture are noticed, the brake system should also be checked for leaks, as these can also increase moisture.”
Regular Maintenance and Monitoring
To prevent moisture from becoming a problem in the first place, regularly checking your brake fluid for moisture content is a straightforward way to maintain your vehicle’s safety. As she summarizes on the importance of regular inspection, Mrs. Wilms settles that, “it is important to regularly check the condition of the brake fluid to avoid dangerous situations on the road and to ensure safety.”
This said, always remember, the condition of your brake fluid directly impacts your ability to stop safely, therefore, this important aspect of your vehicle maintenance must never be gambled. Your safety on the road depends on it.
By Dorcas Kang'ereha
