HOW TO CHANGE THE BRAKE FLUID ? Each motorist has a different relationship with their car, but there are those who delight in DIY with regard to small maintenance operations such as changing the brake fluid . Replacement is necessary in some cases, thanks to the chemical nature of the liquid which tends to absorb moisture: we are here to explain to you when it is necessary to do it and what are the steps to do it without problems … familiar with this kind of operations. Are you ready? Then let’s proceed. The use and maintenance booklet of most cars requires the replacement of the fluid contained inside the braking system every two years, because its properties deteriorate during this period of time. Technically it is defined as a “hygroscopic” liquid, which means that it tends to absorb moisture , and this in the long run can cause problems such as rusting of internal parts of the braking system.
Beware of electronics
The replacement procedure is roughly the same for each car as long as the electronics do not have a hand, as in recent years it has also affected the braking system with bleeds that can be activated through the control unit control, which can only be obtained by going to an authorized workshop . and through the software released directly by the manufacturer. In the latter case it is easy to understand that it will be almost useless to change the liquid independently, but in other cases it is possible to proceed safely as long as you pay careful attention to each step and ask for help from a second person for the more complex operations. Remember that the braking system is one of the safety systemsmain car, and that the slightest mistake could seriously endanger both your life and that of other road users (in short, if you don’t feel like it, go to an authorized workshop….).
The first step is obviously to buy the brake fluid , DOT 4 which can be purchased from any well-stocked car parts. Our advice is to buy two bottles, to obviate both the variability of the system capacity and any losses due to unfamiliarity with the operation.
At this point, open the bonnet and locate the brake fluid reservoir , then put on some gloves and carefully unscrew the cap, taking care not to let dust and dirt enter at any time during all phases of the operation. With a vacuum syringe suck the level into the tray until the remainder has dropped to the minimum mark, then fill with the new liquid up to the MAX.
Remove the rear wheel on the passenger side of the car, which in general is physically the farthest from the reservoir and therefore allows the liquid to travel as wide as possible, and access the bleed screw (distinguished by a cap to prevent it from getting dirty ). Ask a person to repeatedly depress the brake pedal, while connecting a tube with one end to the bleed screw and the other inside an empty bottle that allows the collection of fluids. Once the tube is tight, unscrew the bleed screw half a turn and ask the person in the car to fully press the brake pedal: old fluid will begin to come out and collect it in the bottle. After a while, close the screw, let the brake pedal “pump” again and repeat the operation.
The bleed screw must necessarily be closed only and only when the other person is still pressing the brake pedal, so he is exerting a force that pushes the liquid out. Should it leave before tightening, the depression could suck air and dirt into the system, forcing you to repeat this last step all over to let the bubbles come out.
In the end
During the whole operation, always check that the level in the oil pan never goes below the MIN , otherwise, even in this way, air could enter the system. If it drops to the limit and you are not done yet, simply add more liquid to the tray.
The purging operation can be considered completed when the “new” liquid begins to come out of the bleed life, which means that the entire system has been cleaned of the residues of the old fluid . At this point, close the screw, reassemble the wheel and restore the level of the tray, always paying attention not to let dirt into it. As a last step, press the brake pedal until it regains a certain “hardness”, a sign that the whole system has once again reached the optimum pressure for use.
We remind you that this is an operation that must necessarily be done with the engine off , just as the brake fluid must be disposed of in accordance with the regulations in force (so take it to a disposal center!). The last piece of advice (then we promise we won’t go further!) Is to immediately clean any part of the car that has been in contact with the brake fluid: it has a very aggressive chemical composition, which can discolor the paint or leave annoying traces . on the surfaces it came into contact with. Also wash your hands thoroughly in case of contact, with plenty of running water.
That’s it, you changed the brake fluid yourself. Good road.