MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
198
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 4-6-5 Removing the timing system
(2) Remove the timing tension pulley assembly: loosen
the combined fastening bolt of timing tension pulley and
remove the timing tension pulley. See Fig. 4-6-5.
(3) Remove the timing belt.
(4) Remove the timing idle wheel assembly: loosen the
fastening bolts of timing idle wheel, and remove the
timing idle wheel.
Fig. 4-6-6 Removing the lower body assembly
of oil pan
Fig. 4-6-7 Removing the engine oil pump
assembly
Disassembling the lower body assembly of oil pan
④
(1) Use a spanner to remove the 14 hexagon flange
face bolts (M6×12) fastening the lower body of oil pan in
proper order. See Fig. 4-6-6.
(2) Take off the oil pan lower body from the oil pan
upper body.
Disassembling the engine oil pump assembly
⑤
(1) Orderly remove the 10 hexagon bolt and plain
washer components (M8×40, M8×25 and M8×20)
fastening the engine oil pump and the cylinder body, as
well as the 4 hexagon flange face bolts (M8×25 and
M8×45) connecting the engine oil pump and the oil pan
upper body, and then remove the engine oil pump
assembly. See Fig. 4-6-7.
(2) Take out the outer rotor of engine oil pump and the
rubber seal ring from the engine oil pump cavity of
upper cylinder body. See Fig 4-6-7.
(3) Take out the front oil seal of crankshaft through the
crankshaft oil seal hole of engine oil pump.
Front oil seal remover: 5-8840-2362-0.
Inspection and repair
(1) Replace the engine oil pump assembly if the rotor of
engine oil pump is damaged or heavily worn.
(2) Replace the engine oil pump assembly if the
pressure limiting valve is seized. See Fig. 4-6-8.
Lower body of oil
pan
Timing belt
Upper body of oil
pan
Outer rotor
Seal ring
Front oil seal
