The engine cooling system is liquid, closed with forced circulation

The direction of circulation is shown by the arrows in the figure

The liquid circulates depending on the heating in two circles, in a small and large circle.

When the engine is cold, when the thermostat valve is closed, bypassing the radiator, through the bypass hose 6 into the suction cavity of the water pump, and then into the engine water jacket - this is a small circle.

When the engine is warm, when the thermostat valve is open, through the outlet pipe 7 through the hose to the upper tank of the radiator 1, and from the radiator through the inlet hose 12 to the engine water jacket - this is a big circle.

Cooling system maintenance

Check the coolant level daily before leaving.

The water level in the radiator should be 40 mm below the upper edge of the filler neck, the level of low-freezing liquid should be 70-80 mm.

Scheme of the engine cooling system GAZ-66, GAZ -53

Pour clean soft water into the radiator and change it less often. In the spring (and preferably twice a year), it is recommended to flush the cooling system.

Proper engine operation is the most reliable method of dealing with scale and corrosion in the cooling system. If scale has appeared, then the radiator is washed as follows.

The radiator is removed from the car, then a 10% solution of caustic soda (caustic soda) preheated to a temperature of 90˚ C is poured into it.

After 30-40 minutes, the solution is drained and the radiator is washed with clean running water in the direction opposite to normal circulation. Repeat if necessary.

In order to avoid the destruction of aluminum parts, it is unacceptable to pour an alkali solution into the cooling jacket of the cylinder block.

The caustic soda solution should be handled with care as it burns the skin and corrodes clothing fabrics.

Protection of the engine cooling jacket against corrosion can be carried out as follows.

Prepare a solution of Chromic at the rate of 4-8 g per 1 liter of water and pour it into the cooling system. Work with this solution for a month (best in the summer), and then drain it.

If water boils away from the solution during operation, add water to the system, and if it leaks, add the solution.

You should know that a solution of less than 3 g per 1 liter of chromic acid leads to increased corrosion of aluminum parts.

The drive belts of the units installed on the engines must be tensioned so that they do not slip on the drive pulleys and there are no large loads on the bearings of the units from overtightening of the belts.

The tension of the water pump and fan drive belt on the GAZ-53A car engine should be such that under a force of 4 kg applied in the middle of the tension roller - water pump pulley branch, the deflection arrow does not exceed 10-15 mm, and in the middle of the branch water pump pulley - alternator pulley 10-12 mm.

The tension of the water pump belt is adjusted by moving the tension roller, and the generator drive belt is adjusted by moving the generator itself.

On the GAZ-66 car engine, the water pump drive belt is also the generator drive belt. Its tension is regulated by moving the generator.

The deflection of the generator branch - water pump under a force of 4 kg should not exceed 10-15 mm.

The tension of the compressor and power steering pump drive belts is adjusted by moving the power steering pump.

The deflection of each of the two belts should be no more than 15-20 mm under a force of 1 kg on the branch of the compressor pulley -► the pulley of the power steering pump.

Water pump for GAZ-53, GAZ-66 engines

When overhauling a radiator, the upper and lower banks must be removed from it. The outer surface of the radiator must be cleaned of dirt, and the inner surface of the tanks and pipes must be free of scale.

Dents on the walls of the tanks must be straightened out.

Radiator tubes should be checked with a special rod made to the size and profile of the tubes.

Clogged and dented tubes should be replaced with new ones.

It is allowed to plug no more than 10 tubes and replace no more than 50 tubes

Tubes after repair should be purged with compressed air.

Cooling plates need to be straightened.

The assembled radiator should be thoroughly rinsed with an alkaline solution to neutralize the zinc chloride and water to remove the alkali.

A repaired radiator must be tested for tightness with compressed air at a pressure of 1 kg/cm2.

A radiator filled with compressed air and immersed in water must not let inair.

The radiator cap must be tight. The outlet valve of the plug must be opened under an air pressure of at least 0.45-0.55 kg/cm2. The inlet valve should open at a vacuum of 0.01 -0.10 kg/cm2.

Bent radiator shutter blades should be straightened or replaced with new ones.

Repaired blinds should open and close freely when the lever is rotated within 90°.

When closing the blinds, the gaps between the surfaces of the plates should not exceed 1.5 mm over a length of 200 mm.

Water pumpcentrifugal type.

The pump is sealed with a self-tightening gland with a spring. The rubber collar of the stuffing box and the graphite-lead washer rotate together with the roller 2 (Fig. 2).

Leakage of liquid through the control hole 7 indicates a malfunction of the stuffing box. In this case, the pump should be repaired.

To change the stuffing box parts, the pump impeller must be removed by first unscrewing the bolt.

It is not allowed to plug the control hole 7, as in this case the liquid leaking from the pump enters the bearings and damages them.

The bearings are lubricated through the lubricator 5 until fresh grease appears from the control hole 4. Excess grease must be removed.

Before assembling the water pump, all parts must be wiped and blown with compressed air.

When installing the impeller and the water pump stuffing box into the housing, the end surfaces of the textolite sealing washer must be coated with a thin layer of graphite colloidal lubricant.

The bearings must be lubricated with TsIATIM-201 refractory grease.

Fill the bearings with grease until it appears in the control hole of the housing. When installing, fill the hub cap with CIATIM-203 grease.

When the water pump roller rotates, the impeller should not touch the housing, the water pump seal must be tight.

Check the water pump for leaks on a special stand at 3250 rpm and a water temperature of at least 40 ° C.

GAZ-53 tension roller Before assembly, all parts of the tension roller must be washed and wiped.

When assembling, compress the retaining ring on the axis of the tension roller in the annular groove of the axis to a size of 21.5 mm along the outer diameter of the ring, no more.

Put 4-5 g of CIATIM-201 lubricant into the bearing cavity.