COUPLING AS 1160517 - Caterpillar

Disassembling and inspecting fuel injection nozzle
Illustration 1 g02237997
Disassembling sequence (1) Nozzle retaining nut (2) Nozzle tip assembly (3) Piece (4) Pin (5) Spring (6) Washer (7) Nozzle holderInspect the nozzle tip assembly (2) for carbon deposit and nozzle hole clogging.Inspect the pin (4) and washer (6) for wear and damage.Inspect the spring (5) for settling and breakage.Inspecting and adjusting fuel injection valve opening pressure
Note: Never touch the spray hole during injection.
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Mount the nozzle on the nozzle tester (8) .
Pump the tester handle at a rate of approximately one cycle per second while observing the pressure at which injection starts. If the pressure is not in the standard range, make an adjustment by changing shim.
To adjust the valve opening pressure, remove the retaining nut, and change the shim. The thicker the shim, the more shim increases the pressure.
After adjusting the pressure, tighten the retaining nut to the specified torque.
Check the injection valve opening pressure once again to make sure that the pressure is within the standard range.
Table 1
Item     Nominal     Standard    
Valve opening pressure    
13.73 MPa (1991.00 psi)    
13.93 MPa (2020.00 psi)    Note: Standard is a value of new parts. A change in thickness of the shim by 0.10 mm (0.004 inch) results in a change in the fuel injection pressure by 1 MPa (145 psi). There are ten kinds of shim from 1.250 to 1.700 mm (0.0492 to 0.0669 inch).
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Replacing fuel injection nozzle tip. (9) Nozzle tip endInspecting fuel spray pattern of fuel injection nozzle
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(10) Good (11) Large spray angle (12) After dribble (13) Deflected spray (14) Branched spray
When adjusting the nozzle opening pressure using a nozzle tester, check for clogged nozzle hole, fuel spray pattern, and fuel dribble from the spray hole.
The follows points need to be check for the fuel spray pattern:
Fuel is injected straightly.
Fuel is injected in a spray of fine droplets.
Fuel is injected without after-dribbling.
If the spray pattern is defective (11) to (14), clean or replace the nozzle tip.Cleaning and replacing faulty nozzle
Note: When pulling out the nozzle tip, be careful not to damage the tip.
Illustration 5 g02238034
Loosen the retaining nut, then remove the nozzle tip and clean the needle valve (15) and body (16) .
Clean the nozzle tip in clean wash oil. After cleaning, assemble the needle valve and body in clean diesel fuel.Note: The needle valve and body are precision parts. Handle carefully, and do not change the combination of the valve and body.
Tighten the nozzle tip retaining nut to the specified torque.
If the spray pattern is still faulty after cleaning and adjusting, replace the nozzle tip.Note: When using a new nozzle tip, remove the anticorrosive agent from the nozzle tip, and clean the nozzle tip in wash oil. Then clean the tip again in the fuel before assembly.Reassembling fuel injection nozzle
Illustration 6 g02238037
(17) Tighten the nozzle holder to ... 36.80 2.45 N m (27.14 1.80 lb ft) (18) Tighten the nozzle retaining nut to ... 59 6 N m (43