Doosan DA40 - Compressed air system

SHOP MANUAL
Engine
Ch 1 page 252
Compressed air system
Eect Cause Trouble shooting Action
Compressor does
not maintain su-
cient pressure in the
system
Too much carbon in
compressor cylinder
head or discharge
piping
Empty the compressed
air tank, retain the air in
connected compressed
air components.
Run the engine at
1200 r/min and note the
time it takes for the com-
pressor to discharge:
3 - 3.5 min. for 9/11-
series engines with
90-110 dm
3
tank capac-
ity
2.5 - 3 min. for 14-series
engine with 90-110 dm
3
tank capacity
- If charging time
exceeds specied val-
ues:
- Rectify leakage, if any
- Check/rectify pressure
regulator
- Check/rectify compres-
sor
Exhaust valves leak
Worn pistons and cylin-
ders
Leaking/jammed intake
valves
Defective pressure regu-
lator
Leakage in compressed
air piping
Noise
Too much carbon in
compressor cylinder
head or discharge piping
Check/rectify compres-
so
r as described in the
Workshop Manual
Worn big end/main
bearings
Worn pistons and cylin-
ders
Compressor gear loose
on shaft, see also
“Knocking/noise”,
page “Knocking/noise”
Compressor allows
passage of oil, see
also “High oil con-
sumption”, page
“High oil consump-
tion”
Worn pistons and cylin-
ders
Piston rings tted
wrongly
Overpressure in engine
crankcase.
Compressor does
not discharge
Defective seals on dis-
charge pistons
Discharge mechanism
binding
Defective pressure regu-
lator
Moisture/oil in com-
pressed air system
Air dryer not working
properly
Check operation of air
dryer, change desiccant.
If desiccant is oily, see
“Compressor allows
passage of oil” above