How to check brake fluid

brakes are integral to vehicle safety, so it’s essential to keep them well maintained and check them regularly. Brake fluid, also known as hydraulic fluid, is central to brake safety as it ensures that your brakes perform correctly.

If it’s been some time since your brakes were last checked, keep reading to find out how to check brake fluid and how they help your brakes fully function.

What is brake fluid?

Brake fluid is essential for ensuring your brakes work as they should. It transmits the force applied when your foot pushes the brake pedal to the brake calipers or wheel cylinders, which then applies the brakes and slows down or stops the vehicle. Brake fluid also lubricates the hydraulic system and helps prevent corrosion, so it’s important to keep it sufficiently topped up.

High levels of heat are generated during braking which impacts on brake fluid. The need to prevent it from boiling is essential as this can lead to brake failure. If you notice your brakes are not as responsive as they used to be, it’s essential to get them checked as soon as possible.

It’s important to be careful when topping up brake fluid as the formula is hygroscopic, meaning it absorbs moisture from the air, which can make the fluid less effective. If air enters your brake fluid, your brakes may feel spongy, and your vehicle will take longer to come to a stop. If this is the case, you may need to bleed your brakes.

Brake fluid is also highly flammable and will also damage paintwork if spilled, so always be mindful of this when you top it up.

How to check and top up brake fluid

It’s recommended that you check your brake fluid levels every few months. To check your brake fluid, start by ensuring you are parked on a flat surface to get an accurate reading.

  • Open the bonnet find the brake fluid reservoir. If you’re unsure where this is, refer to your vehicle manual.
  • The brake fluid reservoir is usually white, and you should be able to see the dark brake fluid through the container.
  • You’ll see low and maximum markers – if the fluid is below the low marker, you need to top it up as soon as possible and arrange for your brakes to be inspected.

If after topping up your brake fluid you notice it quickly falls back to the low marker, there could be a leak in your braking system. A low level could also be down to worn brake pads, so if you notice your brake fluid is low, get your brakes checked as soon as you can.

If you need to top up your brake fluid, again make sure you are parked on a flat surface.

  • Start by removing and cleaning the brake fluid reservoir cap so no debris falls inside the container.
  • If there is already debris in the brake fluid, it’s recommended you visit a garage for a brake fluid change.
  • Carefully add the new brake fluid to the reservoir until it reaches the maximum marker and screw the cap back on.
  • Drive your vehicle a short distance, braking every so often and check the fluid again to ensure there has been no drainage.

How often should I change my brake fluid?

It’s recommended that your brake fluid is changed every 24 months or 24,000 miles, whichever is sooner. Book a brake fluid change with one of our experts and we will drain the old fluid and refill it with new fluid. We’ll also dispose of the old fluid in an environmentally friendly way. Alternatively, a brake fluid change is included as part of a major car service.

What brake fluid do I need?

There are 4 different kinds of brake fluid, so it’s important to check which is the right brake fluid for your vehicle. The different brake fluid types are Dot 3, Dot 4, Dot 5 and Dot 5.1. The difference between each of these fluid types are the boiling points and composition. Dot 4 is the most common fluid type but always check beforehand. The correct grade can usually be found on the reservoir or cap.

If you’re not sure what brake fluid you need, simply type in your vehicle registration on our website and the relevant brake fluid will appear in the results. You can also check your owner’s manual to find the correct fluid type.

What happens if I use the wrong brake fluid?

Using the wrong brake fluid for your vehicle can damage the braking system, impacting the responsiveness and its integrity. As a result, you should always check the right brake fluid for your vehicle before topping up.