Doosan DX60R Shop Manual page 377

Disassembly and Inspection of Fuel Injectors
Never use a steel wire brush to clean fuel injectors.
Damage to the nozzle and other components is likely to
result.
1. Clean carbon from used injectors using clean diesel fuel.
Hardened deposits or varnish can be cleaned using a
brass wire brush.
2. Place the fuel injector in a soft-jawed vise with the nozzle
pointing up.
3. Remove the nozzle case nut.
4. Carefully remove the injector from the vise.
5. Turn the injector over and remove the nozzle body, nozzle
valve, valve stop spacer, nozzle spring seat, nozzle
spring, and shims.
6. Inspect the sealing surfaces (2, Figure 292) between the
valve stop spacer and nozzle body for nicks or scratches.
Check the contact area between the valve stop spacer and
the nozzle valve (1, Figure 292) for scoring, or pitting. Use a
magnifier glass to inspect the area.
7. Perform a nozzle valve slide test:
A. Wash nozzle body and valve in clean diesel fuel.
B. While holding the nozzle body vertical, pull the nozzle
valve about 2/3 of the way out (Figure 293).
C. Release the valve. It should fall smoothly to its seat
by it's own weight.
8. Replace the fuel injector assembly if it fails any inspection.
Engine
CAUTION
Figure 292
Figure 293
SP001693
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