The water pump is centrifugal, mounted on the front end of the cylinder block

The pump shaft rotates in two sealed ball bearings that serve to keep grease in the bearings and protect them from contamination.

The place where the rear end of the shaft exits the water pump bearing housing is sealed with a self-compressing stuffing box 13.

The stuffing box consists of a graphitized textolite sealing washer, a rubber seal, a spring that presses the washer against the end of the housing of 9 bearings, and two spring clips.

The protrusions of the washer fit into the grooves of the impeller hub 12.

A special clip 15 holds the stuffing box parts in the impeller when the impeller is mounted on the water pump shaft.

The cavity between the bearings is filled with the grease specified in the grease chart.

Water pump with fan ZIL-131

At the front end of the shaft are installed: fan pulley 3 on bearings and hub 5 of the water pump pulley.

The water pump pulley hub is fixed to the shaft with a split taper bushing 17, a key and a cotter pin nut.

This fastening provides the possibility of tightening the pulley hub in operation in case of a loose pulley fit.

It is necessary to periodically check the fastening of the water pump hub, as loosening of the water pump pulley can damage the fan, radiator and water pump.

To do this, periodically check the tightness of the pulley hub nut.

When loosening the connection, immediately tighten the nut, first remove the cotter pin.

The tightening torque of the nut should be in the range of 8.5-10 kgm. After tightening, the nut must be carefully cottered.

Before lubricating the cavity of the water pump bearings, unscrew the plug 7 that closes the control hole.

Refilling must be done until fresh grease appears from the control hole, then the plug must be replaced.

The water pump is driven by a V-belt from the engine crankshaft pulley.

The water pump drive belt also drives the power steering pump.

The belt tension is adjusted by moving the power steering pump.

With normal tension, the deflection of the belt under the action of a force of 4 kg should be within 8-14 mm (Fig. 2).

Scheme for checking the tension of ZIL-131 drive belts

Six-bladed fan with bent ends of the blades.

The fan is enclosed in a shroud mounted on the radiator frame, which helps to increase the speed of air flow sucked through the radiator.

The fan pulley is located at the front end of the water pump shaft on bearings (Fig. 1), which allows, when overcoming deep fords, to stop the rotation of the fan by loosening the drive belt, without stopping the rotation of the water pump, compressor and hydraulic booster pump.

The fan is driven by a V-belt from the engine crankshaft pulley.

The fan drive belt also drives the alternator.

Belt tension is adjusted by turning the generator on the bracket.

The belt tension is the same as for the water pump belt.

The compressor is driven by the water pump pulley.

With normal tension, the deflection of the belt under a force of 4 kg should be 5-8 mm.