We remove the engine cooling system pump for replacement or repair
Usually the pump is removed for replacement, but there are enthusiasts who repair pumps
Drain the liquid from the engine cooling system, article - "Replacing the coolant"
Remove the radiator.
Remove the generator drive belt.
Removing the cooling pump on the ZMZ-4062 engine
Unscrew the three bolts 1, holding the pump shaft from turning with a screwdriver 2, and remove the reflector 3 and pulley 4 of the water pump.
Unscrew fitting 3 and disconnect tube 4 from the pump.
Unscrew the pump mounting bolt 1, loosen the clamps 2.
Disconnect radiator outlet hose 1 from the pump by loosening clamp 2.
Unscrew the fastening bolts 1 and remove the water pump 2 and the water pump gasket
Removing the pump on the ZMZ-402 engine
Unscrew four bolts 1 and remove fan 2 and fan pulley 3.
Disconnect hose 2 for draining fluid from the heater from the water pump by loosening clamp 1.
Disconnect hose 3 from the pump by loosening clamp 4.
Unscrew the fastening nuts 1 and remove the pump 2 with the pump gasket.
Disassembling the cooling system pump
Pumps installed on engines mod. 4062 and 402, similar in design.
Here is shown the disassembly of the engine pump mod. 4062.
The engine pump mod. 402, you must first unscrew the two bolts and remove the pump cover with the gasket.
The following procedure for disassembling both pumps is the same.
Remove pump impeller 1 using a puller.
The impeller is cast from plastic, but has a metal hub with a thread for a puller.
Use a puller to compress the hub 1 of the pump pulley.
Unscrew the bearing retainer 2 and press the bearing with the pump shaft towards the pulley
Press out the oil seal of pump 1.
Rinse and remove deposits from the pump parts.
Inspection of the engine cooling system pump
The bearing on the pump shaft must rotate freely, without jamming, otherwise replace the bearing and shaft assembly.
If a large amount of play is felt in the bearing, traces of lubricant leakage from under the protective rings are noticeable, or balls roll when the bearing rotates, it must be replaced as an assembly with the roller.
Inspect the impeller. If there are cracks, chips, etc., replace it.
Inspect the oil seal. If there are tears, cracks, the rubber has lost its elasticity, the preload spring is broken, replace the oil seal.
Assembling the engine cooling system pump
Pressing on the pulley hub and water pump impeller
A = (117.5 ± 0.2) mm (engines mod. 402 and 4021);
B = 0 / 0.2 mm (motors mod. 402 and 4021);
C = 0.9 / 1.3 mm (engine mod. 4062)
The pump is assembled in the reverse order of disassembly.
When assembling the pump, inspect the gaskets; if there are tears on them or the gaskets are too compressed, they must be replaced.
When pressing the impeller and hub, the emphasis should be on the pump shaft.
When assembling the pump, maintain the dimensions indicated in the figure.
After screwing the bearing retainer, you need to open the edges of the hole so that part of the metal fits into the slot of the retainer to prevent self-unscrewing.
Installation is carried out in the reverse order of removal.
