MOTOR AS-HYDRAULIC 7R4493 - Caterpillar

Probable Causes
Leaking injector sleeve and/or damaged sealRecommended Actions
Personal injury can result from hot coolant, steam and alkali.At operating temperature, engine coolant is hot and under pressure. The radiator and all lines to heaters or the engine contain hot coolant or steam. Any contact can cause severe burns.Remove filler cap slowly to relieve pressure only when engine is stopped and radiator cap is cool enough to touch with your bare hand.Cooling System Conditioner contains alkali. Avoid contact with skin and eyes.
Table 1
Troubleshooting Test Steps Values Results
1. Leaking injector sleeve and/or damaged seal
A. Remove the valve mechanism covers.
B. Remove the fuel injectors from the cylinder head.
Refer to the Disassembly and Assembly manual for details.
Do not allow the pressure on the cooling system to exceed 103 kPa (15 psi) during the test. Damage to the cooling system may result from applying excessive pressure.
C. Pressurize the cooling system in order to identify the injector sleeve that is leaking. Closely inspect the sealing joint around the top of the injector sleeve. Small amounts of coolant will be dripping from the injector sleeve that is leaking.
Coolant may also be contaminating the fuel system. After the engine is shut down, the retention of pressure in the cooling system may cause the transfer of coolant into the fuel system. Visually inspect the fuel tank for coolant. The contamination of coolant in the fuel system may damage injectors and other fuel system components. Ensure that all of the fuel system components are in good repair prior to returning the engine to service.
Injector Sleeve
Result: The injector sleeve is leaking.
Remove the injector sleeve that is leaking. Carefully inspect the sleeve for damage. If there are visible signs of damage to the injector sleeve, replace the sleeve. Replace the O-ring seals for the injector sleeve and reinstall the sleeve. Replace any damaged components.
Coolant may also be contaminating the fuel system. After the engine is shut down, the retention of pressure in the cooling system may cause the transfer of coolant into the fuel system. Visually inspect the fuel tank for coolant. The contamination of coolant in the fuel system may damage injectors and other fuel system components. Ensure that all of the fuel system components are in good repair prior to returning the engine to service.
Do not crank the engine if a cylinder is full of fluid. Catastrophic damage can occur to the engine.
Evacuate all cylinders of fluid before trying to start the engine.