Checking the fluid level and seal tightness (VAZ-2109)

During vehicle operation, check and, if necessary, restore the coolant level in the expansion tank, which should be 25...30 mm above the "MIN" mark. Check and top up the fluid only on a cold engine.

With a functioning cooling system, the fluid level decreases over time due to water evaporation, and the density increases. Therefore, before adding, you should check its density with a densimeter. If the density is above normal, add distilled water. If the density is within normal limits, add the same fluid to the expansion tank as the system is filled with. When the fluid level is constantly decreasing and frequent topping up is required, visually check the tightness of the hose connections and the fastening of the system instruments. Eliminate leaks at the hose connections by tightening the screw clamps of the hose fastenings. Eliminate coolant leaks under the toothed pulley of the pump by replacing the pump seal, which requires removing the engine and partially disassembling it to extract the pump.

If necessary, you can add clean water, which increases the freezing point of the liquid. Therefore, repair the system at the first opportunity. It is prohibited to add water at negative ambient temperatures.