WEICHAI WD10 Service Manual - page 151
Service Manual for WD10 Diesel Engine
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3) Check measure wear condition and fitting condition of air compressor cylinder sleeve, piston
and piston ring, severely worn parts should be replaced.
4) For compressor air cooling parts, please: Clean up accumulated oil dirt, soot and other dirty
materials on cooling fin. Check the cooling fin and should replace the damaged parts. For
compressor water cooling parts, please: Check the cooling pipe size (recommended minimum
pipe diameter is 9.5mm), Check the flow rate of air refrigerant, minimum allowed flow rate is
5L/min when the engine is running. If refrigerant flow rate is small, check whether cooling pipe
and accessories are rusted or twisted.
5) Check and ensure water temperature is under 93
o
C; check the air valve on gasholder and ensure
it can work normally. It is suggested to equip the machine with automatic exhaust valve and air
drier.
6) When the brake is not used, air leakage (pressure drop) should not exceed 6.9kPa/min, and
when depressing the brake, that value is 20.7kPa/min. If there is severe leakage, check the
system and remove the fault. Check whether unloading system is working and repair it.
7) Check whether oil pressure in crankcase is too high, replace or repair ventilating device of
crankcase if so. If the oil dipstick is loose or partially raised, then oil pressure in crankcase is in
problem.
8) Check engine oil pressure (air compressor oil inlet port), compare it with rated pressure.
9) Replace with qualified lubricating oil (engine oil).
Only after ruling all the causes above out should the air compressor be repaired or replaced.
(4) Air compressor produces abnormal sound.
Fault phenomenon: Metal crash, rhythmic knock or grinding squeal
Possible causes:
1) Connecting rod sleeve or bearing shells are severely worn, connecting rod bolts are loose, main
bearing shell is worn or damaged that result in crash noise.
2) The belt is too loose, driving and driven pulley groove type is not uniform, which lead to
slipping squeal.
3) No engine oil is supplied to air compressor, dry friction of metal leading to squeal.
4) Loose fixing bolts.
5) Loose gear fastening nuts results in oversized tooth space, which will bring rhythmic knock.
6) Foreign matter in piston head.
Troubleshooting:
1) Check whether connecting rod bearing shells, connecting rod sleeve and main bearing shell is