3.13. Check of functioning of the cooling system and frost resistance of cooling liquid, liquid replacement

General information

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.


  1. Check of the cooling system has to be made at the cold engine therefore it is better to be engaged in it before the first in the present day trip or not earlier than in three hours after an engine stop.
  2. Slowly, being careful in case the engine yet not absolutely cooled down, uncover a broad tank. Carefully wash out it clear water from within and outside. Also wash out a jellied mouth of a tank. Existence of traces of corrosion in a jellied mouth means that cooling liquid should be replaced. Cooling liquid in a broad tank has to be rather pure and transparent. If liquid has a brownish shade, empty system and fill in in it new cooling liquid (see the Section Check of Level of Working Liquids).
  1. Attentively study hoses of a radiator and a heater. Examine hoses on all length, at identification of cracks, swellings and signs of aging of material you make replacement. It is easier to find cracks by tightening of a hose. Pay special attention to installation sites of the fixing collars capable to cut through or pierce hoses.
  1. Make sure of reliability of fastening of all hose connections. Leak of cooling liquid is usually shown in the form of white or brown-red deposits near the place of violation of sealing. If for fastening any of hoses collars of wire type are used, it makes sense to replace them worm/screw.
  2. Compressed air blow a forward part of the heat exchanger of a radiator, and at the corresponding complete set, also the К/В condenser. Remove them gaps between plates of heat exchangers remains of insects, foliage and other foreign objects, - try not to damage plates and not to cut about them fingers.
  3. If need for adjustment of level of cooling liquid arises regularly while traces of any external leaks are absent, it is necessary to make check of the cooling system pressure in conditions HUNDRED.

Check of frost resistance of cooling liquid

Do not allow hit of antifreeze on open parts of the body and the painted surfaces of the car. Immediately wash away casual splashes a plentiful amount of water. Remember that antifreeze is extremely toxic liquid and its hit in an organism even in small amounts is fraught with the most serious consequences, up to a lethal outcome. Never leave antifreeze stored in leaky closed container, immediately collect the cooling liquid spilled on a floor. Remember that the sweetish smell of antifreeze can draw to itself attention of children and animals. About rules utilization of the fulfilled cooling liquid consult on HUNDRED, - in many countries special points on different reception of working off are equipped, - at all do not merge old cooling liquid in the sewerage or on the earth!

Recently nontoxical grades of antifreeze are developed, nevertheless, they also had to be utilized in an organized order.


  1. Before a winter season it is necessary to check surely concentration of antifreeze in cooling liquid, especially if in system in the course of summer operation of the car in system water was added, - use appropriately graduated areometer.
  2. 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.
  3. Carefully turn off a stopper of a broad tank.

At the hot engine the stopper of a broad tank should be opened extremely carefully, previously having covered it with rags. It is necessary to open a tank only at a temperature of cooling liquid not above 90 °C!

  1. Pump out test of liquid in the working camera of the areometer.
  2. In midlatitudes concentration of antifreeze has to providing protection of system up to the temperature of -25 °C, in hard frosts to -35 °C.

Replacement of cooling liquid of the engine

Replacement of cooling liquid has to be made strictly according to the Schedule of routine maintenance of the car (see the Section Schedule of Routine Maintenance). The order of implementation of the procedure is given above in the Section Check of Level of Working Liquids.