WEICHAI WD10 Service Manual - page 149
Service Manual for WD10 Diesel Engine
139
1) Air pressure gauge failure.
2) The transmission belt between air compressor and engine is loose and slipping; pipe from air
compressor to gasholder is fractured or air leakage in the joints.
3) Oil-water separator, pipeline or air filter is blocked due to too much deposit sediment.
4) Bad sealing of air compressor discharge valve, the valve spring is weak or broken; loose fixing
bolts, sand hole and damaged gasket of air compressor cylinder cover that leading to air
leakage.
5) Severe wear of air compressor cylinder sleeve, piston and piston ring that leading to air
leakage.
Troubleshooting:
1) Observe air pressure gauge, if it indicates insufficient air pressure, try to keep the engine run at
medium speed for several minutes, if the pressure doesn’t rise or rises slowly, and when
depressing the brake pedal, strong deflating sound comes out, then the air pressure gauge must
be damaged, repair the gauge.
2) If there is no deflating sound or small deflating sound in the above test, then check whether air
compressor belt is loose, whether pipe from air compressor to gasholder is fractured or whether
there is air leakage in the joints.
3) If the air compressor doesn’t charge gasholder, check whether oil-water separator, pipeline or
air filter is blocked due to too much deposit sediment, clean away the sediment if so.
4) If still cannot find out the cause after the above inspections, then check air compressor
discharge valve for air leakage, check whether the valve spring is weak or broken, check
whether there is sand hole on cylinder cover, whether the gasket is damaged, repair or replace
the damaged parts.
5) Check wear condition of air compressor cylinder sleeve, piston and piston ring.
6) Check and adjust installation direction of unloading valve (should be conform to the arrow).
(3) Air compressor pumping oil.
Fault phenomenon: There is engine oil overflows in air filter and air compressor exhaust port, and
engine oil comes out with water when discharging the gasholder (wet).
Possible causes:
1) Large intake resistance or bad intake filter.
2) Large oil return resistance.
3) Severe wear of air compressor cylinder sleeve, piston and piston ring; inversely installed or
jammed oil ring that results in air compressor pumping oil.