Bleeding the brake system

Air in the brake system «turns» any brake in «air pump», therefore, in this situation, urgently pump the brake system. For example, after carrying out all the work in which it was necessary to remove the brake hoses or open the brake pipelines. Often it is enough to pump only the brake circuit with which the work was carried out. For SAFETY purposes, however, it would be better if both circuits were bled. ALWAYS use new brake fluid (DOT4 ESD specification - M6C57A) and clean transparent plastic hose (glass washing system, aquarium aeration system). In addition, you must have an assistant. Put your Mondeo on level ground. During the entire pumping process, keep the contents of the compensation tank on the mark «MAX». Never lower the brake fluid level below the mark «MIN». If this happens, then a new portion of air will again enter the system through the top-up hole.

Be careful not to get brake fluid on the paintwork. Otherwise, quickly rinse the area with clean water, as the varnish becomes «false» or even dissolve.

Height difference X: approx. 30 cm must be between the purge tank and the air valve. If the reservoir is at the correct height, then the air valve is under fluid pressure, so that air can no longer enter the brake system through the threads.

PROCEDURE

Disconnect the battery cable and raise the vehicle on level ground. Begin the bleeding process at the air valve that is furthest away from the brake master cylinder. Insert the bleed hose onto the air valve and... ... insert the other end of the hose into a reservoir with a small amount of brake fluid. Air valve with connected hose. Open the valve about half a turn. Let the assistant slowly «shakes» brake pedal until fluid with air bubbles flows into the reservoir. At the same time, make sure that the brake fluid remains in the compensation tank. If there are no more air bubbles and only brake fluid comes out, then let the assistant hold the pedal in the lowest position, and at this time close the air valve yourself. Repeat this process for all valves and then close their protective caps. Check the brake fluid level in the reservoir and top up to the top mark. Put the car on wheels and complete the work in reverse order.

TECHNICAL DICTIONARY

Brake fluid The main constituents of brake fluid are polyglycol and polyglycol ether. This mixture remains fairly liquid at –40°C and has a very high boiling point of about 290°C. Its composition already speaks for itself: the brake fluid is hydroscopic - it readily «absorbs water» from the air through the sealing cap of the compensation tank. This is about 2% annually. If the proportion of water in it is only 2.5 percent, then the boiling point will already drop to 150°C. In this case, with very hot brakes (driving in mountainous areas, full braking, driving with a trailer) Vapor bubbles may form in the brake fluid. Steam bubbles have the same effect as air in the brake system - the brake pedal can «fall through», sometimes it seems that she is drowning in emptiness. Therefore, for your own safety, change the brake fluid every two years. If your Mondeo shows up regularly at the Ford workshop, this procedure is automatic. Disposal as special waste - used brake fluid Brake fluid is poisonous. Therefore, avoid contact with your lips or open wounds. Brake fluid hardly corrodes metal or rubber, but it acts aggressively on car paint. Brake fluid that has been drained from the system must be disposed of in each case. Also, do not use brake fluid from containers that have been open for a long time. Used brake fluid is classified as special waste, so dispose of this «poison juice» properly.