Brake fluid quantity: 0.5 liters.
Type of fluid used: DOT-4 (ELF 650).
We perform work on a viewing ditch or overpass.
We unscrew and remove the cover with the sensor without disconnecting the wire block from the sensor.
At this point, you can check the health of the liquid level sensor. For this…
... we place the sensor in a vertical position on the tank and turn on the ignition.
If the sensor is OK, then the parking brake and brake system malfunction indicator in the instrument cluster should light up (the parking brake lever must be fully released when checking).
We pump out the old liquid from the tank with a rubber bulb or an ordinary syringe..
We replace by topping up and pumping (see below).
Bleeding the brake system (see «Bleeding the brake system») and clutch (see «Bleeding the clutch») until the new fluid (lighter than the old) will not begin to come out of the bleeder valves of all working cylinders.
After bleeding the brake and clutch hydraulic drives, we bring the fluid level in the reservoir to normal.
Min and Max marks on the brake fluid reservoir
Addition:
Everyone knows that brake fluid is hygroscopic and should be changed from time to time. under the word «change» automakers have in mind a complete replacement of the fluid in the system, including the ABS and ESP units, if any. But in reality, it happens, especially when the repair area is inaccessible to the client, that the replacement of the brake fluid occurs according to an extremely simplified scheme: the master sucks off the old - muddy and dirty brake fluid from the tank with an ordinary enema and fills it with a new one - transparent and clean. Even if the client gets under the hood after the replacement, he will not see any crime there - the liquid is clean, what questions?
It is clear that no one gives a damn about the client, except for himself, but after all, in the brake circuits and electronic units there is a brake fluid that has caught water, which categorically does not correspond to what should actually be there. Even if you are lucky and after a series of intense braking, the contours after such «substitutions» if they don’t boil and the pedal doesn’t get stuck, then you can’t count on electronic assistants - ABS and ESP units are very sensitive to the moisture content in glycol - usually 0.4% of water is enough for the electronic unit to stop working adequately. By the way, depending on the brand of the car, the ABS and ESP systems are pumped in different ways. The master, of course, must know exactly how, otherwise it is worth looking for another place for maintenance. So during the replacement of the brake fluid, the main condition for the replacement should be access to the repair area - it is not worth risking your safety for the sake of another hack.
Today we will not consider the agony of choosing a brake fluid, but it is worth remembering that the next product may turn out to be better, the main thing is not to confuse polyglycol with silicone. Fortunately, there are usually warnings on the packages. Aware of service integrity issues and consumer disregard for maintenance, Bosch recently released an ENV-branded fluid that lasts up to four years instead of the previous two, which is encouraging. Perhaps, of course, Bosch cared more about the performance of its new generation ESPs, with serial number 9.3, and its reputation, but it didn’t forget about safety either.