A bicycle, like any vehicle, requires regular maintenance, including periodic replacement of the brake fluid. The frequency of its replacement will depend on the terrain and the riding style of the cyclist.
Bicycle brakes from different manufacturers may have significant design differences, but one principle unconditionally unites them: the brake fluid must be changed once a year, regardless of how well or poorly the braking system works.
If a cyclist spends a long time in the saddle and rides in an area where frequent, strong or sharp braking is required, then it is possible that the brake fluid will need to be replaced even more often: once every six months.
It is not difficult to visually determine the need to change the fluid: by installing the brake lever parallel to the ground and unscrewing the expansion tank cap, the cyclist can assess whether there are impurities in the brake fluid, whether its color has changed, or whether it has become cloudy. All of the above factors indicate the need for an oil change.
Preliminary preparation for self-replacement
To avoid contamination of the brake pads with oily fluid, it is recommended to remove them from the bike before changing the oil. For the same reason, it is advisable to cover the wheels with something.
When choosing a brake fluid for your bike, it is important to adhere to the manufacturer's recommendations. It is not worth replacing the original oil with analogues for car brake systems: car oil may not match in terms of viscosity, contain additives that are not suitable for bicycles.
In addition, automotive fluids can corrode rubber seals, damaging the entire braking system of your bike.
Brake fluid replacement tools
Before you start changing the brake fluid on your bike yourself, you need to take care of the set of tools. You will need a little of them: a Phillips screwdriver, a # 7 wrench, a set of hex keys, a container for draining used oil, a piece of plastic tube and a medical syringe (optional, but very convenient device for filling oil).
Replacing the brake fluid
To drain the spent fluid, you must put a piece of the tube on the brake caliper valve (caliper) and open it with a wrench, directing the free end of the tube into the drain container.
Pressing the brake lever will drain the waste fluid. After making sure that the fluid is completely drained, you can proceed to filling the hydraulic system with fresh oil.
To do this, using a medical syringe or manually, you need to fill the expansion tank to the very edges, and press the brake lever several times. Fluid will begin to flow into the hose, squeezing out air bubbles. As the level of liquid in the tank decreases, it needs to be refilled little by little so that the tank does not remain completely empty.
When the brake line is full and excess fluid is poured from the tube into the supplied drain container, the caliper valve can be closed.
The system should not contain air - this is checked by pressing the brake: soft and sluggish pressing indicates the presence of air. In this case, the valve must be reopened and the brake fluid topped up by pressing the brake lever until a hard pressure is felt.
Having tightly closed the brake caliper valve, and removing the tube, you need to add liquid to the expansion tank to the very top, after which the tank cap can be screwed on.
