Mercedes S-Class W-220

1. Many serious violations in operation of the engine are connected with malfunctions of the cooling system. If the car is equipped with automatic transmission, then its functioning and service life are also directly connected with operation of the cooling system.
2. Check of the cooling system has to be made at the cold engine therefore it is better to be engaged in it before a trip, the first for the present day, or not earlier than in three hours after switching off of the engine.
3. Slowly, being careful in case the engine yet not absolutely cooled down, uncover a radiator. Carefully wash out it clear water from within and outside. Also wash out a jellied mouth of a radiator. Existence of traces of corrosion in a jellied mouth means that the cooler should be replaced. The cooler in a radiator has to be rather pure and transparent. If it has brownish color, drain system and fill in in it a new cooler.

4. Carefully check radiator hoses, and also heater hoses which have smaller diameter. Check cooling system hoses on all length, making replacement of any burst, blown up or worn-out hose. It is easier to find cracks if to squeeze a hose a hand. Pay special attention to the collars holding hoses on cooling system components. These collars can cut or pierce hoses that will lead to leakage of a cooler.

5. Make sure of reliability of fastening of all hose connections. Leakages of a cooler are usually shown in the form of white or rusty color of deposits in the field of sealing violation. If on your car collars of wire type are used, then it is possible, there is a sense to replace them with collars of screw type.
6. By means of compressed air or a soft brush clear a forward part of a radiator (and also the air conditioner condenser where it is available). Remove all insects, the leaves and other foreign objects which got on radiator edges. Be very careful not to injure an edge and not to cut about them fingers.
7. If cooler level constantly falls, and you did not find any leaks, it is necessary to make check by pressure of a cover of a radiator and all cooling system.

1. Slightly warm up the engine so that the top hose of a radiator heated up. At measurement of concentration of antifreeze temperature of liquid has to make about +20 °C.

At the hot engine the stopper of a broad tank should be opened carefully. There is a danger of a burn! It is necessary to put a rag on a stopper. Open a stopper only at a temperature of liquid no more than + 90 °C.

2. Carefully turn off a stopper of a broad tank.

3. Gather liquid by means of an areometer pear.

4. In our latitudes the concentration of antifreeze providing protection of system up to the temperature of -25 °C at especially frigid climate to –35 °C is sufficient.

1. For removal of cooling liquid place the pallet under a radiator and turn off a stopper of a drain opening of a radiator.
2. Completely it is impossible to remove old liquid from system (without full dismantling of the engine) therefore all volumes specified in Specifications are conditional. In practice you will be able to fill in in system about 2/3 of the ordered amount of liquid.
3. After filling of system with fresh antifreeze place on a broad tank a label with the indication of concentration, brand of antifreeze and date of replacement. Any subsequent replenishment of system (before planned replacement) has to be made only by the specified liquid.

1. If after liquid replacement the engine overheats, the reason, most likely, available air traffic jams in system. These traffic jams do not allow liquid to circulate on all system. They appear as a result of too hasty gas station of system.
2. If you consider that in system there are air traffic jams, first of all try to squeeze all visible hoses in turn. You at once define, the hose is filled with liquid or air. As a rule, all air traffic jams disappear after the first (after liquid replacement) start of the engine.
3. At the working heated-up engine include a heater and its fan. Warm air has to come to salon in enough. If temperature of the given air low, the reason, perhaps, is an air stopper.
4. Consequences of emergence of air traffic jams in system can be very serious (not simply decrease in overall performance of a heater). The big stopper can stop circulation of liquid in the engine. To make sure of lack of traffic jams in the engine, touch the top hose of a radiator at the working engine — it has to be hot. If the hose cold, it demonstrates existence of an air stopper in the engine or about the faulty thermostat.
5. If you could not get rid of air traffic jams, allow the engine to cool down completely, uncover a broad tank, try to squeeze system hoses. If it did not help, merge all cooling liquid in a pure container and again fill system with the same liquid, following the recommendations given above.