Komatsu 4D98 Series Shop Manual page 27

2. Troubleshooting
Starting failure
Insufficient Pccrex- 5
Hunting
B
Lubricating oil
Cooling Air
engine output haust color '5 0 water intake
e
Exhaust smoke
_m
UJ
Corrective action
Cause
Trouble symptom
Excessive cooling effect of radiator
Insufficient cooling effect of radiator
6 insufficient cooling water level
L
%
s Cracked water jacket
F Slackened fan belt
g Defective thermostat
B
5
0
0
0
0
00
0
0 Defective thermostat (kept closed) (See 3.9 (1) in Chapter 3.)
0 0 Defective thermostat (kept opened) (See 3.9 (1) in Chapter 3.) 01
slipping fan belt (See 3.4 in Chapter 3.)
0 0 Check water leakage from cooling water system.
00 0
Repair or replace.
0 0
Adjust the belt tension. (See 3.4 in Chapter 3.)
00
Check or replace. (See 3.9 (1) in Chapter 3.)
Improper properties of lubricating oil
00
0 0
00
Use
proper lubricating oil. (See 1.3 (2) in Chapter 1.)
Leakage from lubricating oil piping system 0
0
Repair.
E Insufficient delivery capacity of trochoid pump
0
Check and repair. (See 5.5 in Chapter 5.)
S
z Clogged lubricating oil fifter
00
Clean or replace.
g Defective pressure regulating valve
0
Clean, adjust or replace.
c
5 Insufficient lubricating oil level
0
Add proper lubricating oil. (See 3.1 in Chapter 3.)
0
0
&
3
Too early timing of fuel injection pump
000
0
Check and adjust. (See 3.7 in Chapter 3.)
Too late timing of fuel injection pump
0000
0
0 Check and adjust. (See 3.7 in Chapter 3.)
Improper properties of fuel oil
00000
0 Use proper fuel oil. (See 1.3 (1) in Chapter 1.)
Water entrance in fuel system
0 0 0 0' 000
Perform draining from the fuel fifter.
Clogged fuel filter
00 0
Clean or replace.
Air entrance in fuel system
00 0
Perform air bleeding.
5 Clogged or cracked fuel pipe
00 0
Clean or replace.
E Insufficient fuel supply to fuel injection pump
00 0
Check the fuel tank cock, fuel filter, fuel pipe, and fuel feet
II
pump.
5
2 Uneven injection volume of fuel injection pump
0000 0000 0
Check and adjust. (See Chapter 7.)
Excessive fuel injection volume 0 00
00
00 Check and adjust. (See Chapter 7.)
Poor spray pattern from fuel injection nozzle
0000
0000 0
Check and adjust. (See 3.6 in Chapter 3.)
Priming failure
0
Foreign matter trapped in the valve inside the priming pump. (Dis
assemble and clean.)
Clogged strainer at feed pump inlet
0
Clean the strainer.
I I
2-2