How is Brake Fluid Added?

Your vehicle's owner’s manual recommends regular inspections and top-ups of the brake fluid. Beyond maintaining the correct volume, it is critical to monitor the fluid’s condition, as it directly impacts your vehicle's braking performance and overall safety.

The Role of the Hydraulic System

Every time the brake pedal is engaged, the vehicle relies on a sophisticated hydraulic system to assist in deceleration. This system multiplies the force applied by the driver, allowing the vehicle to slow down or stop effectively. Because this process is central to vehicle control, the integrity of the brake fluid is paramount.

Environmental Impacts and Fluid Degradation

Most brake fluids (such as DOT 3 and DOT 4) are hygroscopic, meaning they naturally absorb moisture from the air. This occurs through the reservoir or brake lines, even when the vehicle is stationary. While this process is accelerated in hot and humid climates, it is a standard occurrence in all environments.

Moisture is the primary cause of brake fluid degradation. As water content increases, the fluid’s boiling point decreases, which significantly elevates the risk of brake failure. In some cases, a system may absorb up to 2% of moisture every year of operation.

Heat Management and Braking Efficiency

During standard driving, friction between the brake pads and discs generates intense heat, which can raise the fluid temperature to over 200°C. If the fluid contains moisture, it may begin to boil, creating small air bubbles. Unlike fluid, air is highly compressible; this leads to a "spongy" brake pedal feel, increased pedal travel, and dangerously long stopping distances.

How to Inspect and Add Brake Fluid

Unlike brake pads or rotors, which show visible signs of physical wear, the condition of brake fluid is often overlooked. To ensure optimal safety, the brake reservoir should be inspected monthly.

If the fluid level is below the recommended line, follow these steps to top it off:

Locate the Reservoir: Identify the brake fluid reservoir under the hood (check your owner’s manual for the exact location).
Clean the Cap: Before opening, wipe the reservoir cap and the surrounding area to prevent dirt or moisture from entering the system.
Check the Level: Observe the Minimum and Maximum markers on the side of the translucent reservoir.
Add Fluid: If the level is low, carefully add the specific type of brake fluid recommended by Ford (e.g., DOT 4) until it reaches the "Maximum" line. Avoid overfilling.
Secure the Cap: Replace the cap immediately to minimize the fluid's exposure to the atmosphere.

Note: If you find that you are frequently topping up your brake fluid, it may indicate a leak or significantly worn brake pads. In such cases, please visit an authorized service center for a professional inspection.

Preparation and Safety Protocols

Before performing any maintenance on your vehicle's braking system, please adhere to the following safety guidelines:

Vehicle Positioning: Ensure the vehicle is parked on a level surface.
Personal Protective Equipment: Brake fluid is toxic. Always wear appropriate eye and hand protection during handling.
Safety Precautions: Secure loose clothing and keep limbs clear of the cooling fans. Note that fans may activate automatically, even when the engine is powered off.
Fluid Specifications: Consult your owner’s manual for the exact brake fluid specification required. Use only new fluid from a sealed, clean container. Never substitute brake fluid with any other automotive fluids.
System Integrity: Never allow the master cylinder to run dry, as this can lead to total brake failure.
 

Step-by-Step Guide: Adding Brake Fluid

Locate the Master Cylinder: With the engine off, open the hood. The brake master cylinder is typically located at the rear of the engine bay on the driver’s side.
Protect Your Vehicle: Cover the fender to protect the exterior finish. Brake fluid is corrosive and can cause permanent damage to the vehicle's paint.
Clean the Area: Use a clean cloth to wipe the reservoir, cap, and fluid lines. This prevents contaminants or moisture from entering the system during service.
Inspect Fluid Levels: Check the markings on the side of the translucent reservoir. If the fluid is at or above the “MIN” line, no additional fluid is required.
Replenish Fluid: If the level is below the MIN line, carefully remove the reservoir cap. Add the specified brake fluid until the level reaches just below the MAX line. Do not overfill.
Sanitize the Cap: Before installation, use a lint-free cloth to clean the interior of the reservoir cap to remove any debris or old fluid.
Secure the Reservoir: Place the cap back onto the reservoir and press down firmly on all four corners until it clicks into place.

Note: If you notice the fluid level continues to drop or if the fluid appears dark/discolored, please visit Ford Dealership for a professional inspection. If you are uncomfortable performing this maintenance yourself, our factory-trained technicians are available to assist.

Brake Fluid Types

Understanding the differences between brake fluid classifications is essential for maintaining system performance:

DOT 3 and DOT 4: These are glycol-based fluids. The primary difference is their boiling point; DOT 4 has a higher boiling point, making it suitable for high-performance driving or heavy-duty use. Always verify in your owner’s manual if DOT 4 is compatible with your specific model.
DOT 5: This is a silicone-based fluid. While it does not absorb moisture and has a very high boiling point, it is not compatible with systems designed for DOT 3 or DOT 4. Mixing these or using DOT 5 in an incompatible system can cause significant internal damage.