Brake Fluid
Brake fluid is a small but essential component that makes your entire braking system work effectively. As time passes, it absorbs moisture, reducing its ability to hold pressure and potentially increasing your stopping distance when you need it most.
That’s why regular brake fluid checks and replacements are an essential part of staying safe on the road.
At Shires Garage in Langport, we deliver expert brake fluid services tailored to your vehicle’s needs, following manufacturer recommendations for complete peace of mind. We serve drivers across Taunton and nearby areas with reliable, friendly service. Call 01458 250570 today to schedule a brake fluid check or replacement and keep your car’s braking system in peak condition.
What Brake Fluid Does for Your Vehicle
Brake fluid is one of the key elements that make your braking system work smoothly. It keeps pedal feedback firm, protects key components, and ensures the brakes respond the moment you need them.
This hydraulic fluid transfers the force of your foot on the brake pedal into the braking system itself. Since brake fluid can’t be compressed, it delivers that energy with accuracy and consistency. As soon as you press the pedal, it pushes pressure through the system, engaging calipers or wheel cylinders to press brake pads or shoes onto the brake discs or drums.
It also prevents corrosion inside the system and provides vital lubrication. Brake fluid has to endure high heat and pressure, so ensuring the right type and quality of fluid is essential for your safety.
The Mechanics Behind Brake Fluid
Let’s break down the process of how brake fluid operates.
When you step on the brake pedal, you’re not physically applying force to the wheels.. Your foot instead activates a master cylinder, which compresses the brake fluid. This hydraulic pressure is transmitted via brake lines to calipers or wheel cylinders, depending on your vehicle’s setup.
This pressure then forces the brake pads or shoes against a brake disc or drum, producing the friction required to slow or stop your vehicle. When brake fluid is in good condition, it stays incompressible, which means the pressure is transmitted immediately and consistently, giving you reliable control with each press of the pedal.
Yet brake fluid has an even broader role. It must maintain this performance under extreme temperatures and pressure while supporting features like ABS and electronic stability systems, which rely on precise fluid performance to function properly.
Though small in volume, Brake Fluid’s contribution to your car’s braking power is enormous.
Where to Find the Brake Fluid Reservoir
Lift the bonnet of most cars and you’ll notice a compact, translucent plastic container near the back of the engine bay, typically on the driver’s side – this is the brake fluid reservoir.
The reservoir includes a rubber diaphragm or cap that helps keep moisture and air out. This feature matters because brake fluid naturally draws in water over time, reducing its ability to transmit hydraulic pressure effectively. Its see-through casing allows a quick visual check of levels without removing the cap. However, to examine the colour or quality of the brake fluid properly, the cap must be removed during inspection.
Though small, this reservoir is a valuable indicator of your braking system’s health. If you spot a significant drop in fluid level or notice discolouration, it’s best to have it checked by skilled technicians like those at Shires Garage.
Understanding DOT Brake Fluids
Yes, different types of brake fluid exist, and selecting the correct one is key to keeping your brakes safe and effective. Brake fluids vary in composition, and using the wrong type can damage your braking components or lower performance.
Here’s a breakdown of the common grades:
- DOT 3 Brake Fluid – Glycol-based with a lower boiling point, usually found in older cars without advanced braking systems. It’s hygroscopic, meaning it absorbs moisture.
- DOT 4 Brake Fluid – Standard in most modern vehicles, it has a higher boiling point than DOT 3 and is better for systems with ABS or traction control. It also absorbs moisture and needs routine replacement, similar to DOT 3.
- DOT 5 Brake Fluid – A silicone-based fluid that doesn’t take on water. It’s mainly used in classic or specialist cars. It can’t be mixed with DOT 3 or 4 as it may cause seal damage or brake failure.
- DOT 5.1 Brake Fluid – Delivers similar performance to DOT 5 but with a glycol base like DOT 3 and DOT 4, making it suitable for high-performance systems.
The Brake fluid your vehicle needs can’t just be chosen randomly. Using the wrong one can cause damage. At Shires Garage in Langport, we ensure your car gets the correct brake fluid to keep your braking system in peak condition.
What Causes Brake Fluid to Break Down
Brake fluid is engineered to perform under pressure, but it gradually degrades due to exposure to heat, moisture, and contamination. If it isn’t replaced at the intervals recommended by your manufacturer, your braking system can become less responsive and, in extreme cases, unsafe.
These are the main reasons brake fluid deteriorates:
Moisture Absorption – Brake fluid is hygroscopic, meaning it naturally absorbs water from the atmosphere, even through microscopic pores in seals and hoses. This extra moisture lowers the boiling point, increasing the chance of vapour lock. Vapour lock occurs when fluid boils under heavy braking, forming bubbles that reduce its ability to transmit pressure effectively.
Heat and Pressure – Each time you brake, heat builds up within the system. Over time, these extreme conditions cause the fluid to break down chemically, leaving it less stable and less reliable under hard braking.
Chemical Stability and Additives – Brake fluids contain special additives to guard against corrosion and keep rubber seals protected. As the fluid ages, these additives lose their strength, leaving vital components vulnerable to wear.
Contamination – Rust particles, rubber fragments, or even a trace of incompatible fluid can contaminate the system, damaging seals and reducing the precision of the brakes.
Old or Incorrect Fluid – Using the wrong grade of brake fluid or allowing it to remain in the system past its service life can interfere with ABS and traction control functions, leading to unpredictable performance during sudden stops.
At Shires Garage in Langport, we inspect brake fluid quality during every service, advising when replacement is needed to maintain peak braking performance and safety.
Key Signs of Degraded Brake Fluid
Brake fluid doesn’t have its own dashboard alert, which means identifying potential issues early is key to staying safe. Regular servicing at Shires Garage in Langport helps ensure your brake fluid is always at its best, preventing hidden faults that could affect your stopping power.
Look out for these signs that your brake fluid might need professional attention:
- A Spongy Brake Pedal – If the pedal feels soft or requires extra pressure, moisture or air could be interfering with the fluid’s ability to transmit hydraulic force.
- Brake or ABS Warning Lights – Some vehicles display a warning light when brake fluid levels are low or pressure imbalances are detected. It’s important to have this checked quickly.
- Unpleasant or Burned Odour – A harsh chemical smell from the fluid when the reservoir cap is removed is a strong sign that the fluid has deteriorated and should be replaced.
- Discolouration or Dirt – Fresh brake fluid is clear or pale. If the fluid looks dark, cloudy, or dirty, it could indicate contamination from rust, moisture, or debris.
If you notice these symptoms, contact Shires Garage to arrange a brake fluid inspection and keep your braking system safe and reliable. Our expert team are ready to help you.
The Consequences of Ignoring a Brake Fluid Change
Brake fluid is a small but vital part of your vehicle’s safety system, and neglecting it can lead to significant problems. Because brake fluid deteriorates gradually, issues often build up without obvious warning signs until it’s too late.
When brake fluid absorbs moisture, its boiling point drops, making it less effective at transmitting pressure. This can result in a soft or unresponsive brake pedal, longer stopping distances, or sudden brake fade during emergency situations. Over time, degraded fluid also causes corrosion inside the braking system, damaging seals, calipers, and other components.
If left unchanged for too long, contaminated fluid can even lead to complete brake failure under high heat, as vapour bubbles form and prevent pressure from reaching the brake pads or shoes. This is a dangerous situation that could easily be avoided through routine maintenance.
At Shires Garage in Langport, we monitor brake fluid condition during every service and recommend changes based on manufacturer guidance. This ensures your braking system remains reliable and prevents small issues from turning into serious risks.
Expert Brake Fluid Care at Shires Garage
Brake fluid slowly absorbs moisture and loses its effectiveness over time, reducing its ability to transmit hydraulic pressure when you need it most. If left unchanged, this can lead to longer stopping distances, poor pedal response, or even brake failure in extreme situations. That’s why routine brake fluid checks are critical to keeping your braking system safe and responsive.
At Shires Garage in Langport, we provide professional brake fluid checks and replacements, using the exact specification recommended by your vehicle’s manufacturer. Our experienced team inspects your fluid during every service and advises when a replacement is needed to maintain optimal braking performance. You’ll receive the same level of care as a main dealer, but with better value and a friendly, local approach.
Why choose Shires Garage?
✔ We always follow manufacturer-approved standards
✔ Highly trained and experienced technicians
✔ Brake fluid checks included with every service
✔ All work guaranteed for 12 months
If your brake pedal feels less firm or it’s been a while since your last fluid change, call 01458 250570 to book your brake fluid service today. We’ll help keep your car’s braking system dependable and safe.
