BRACKET 4Z9461 - Caterpillar

Illustration 4 g02909817
(8) Air inlet elbow
Table 6
Troubleshooting Test Step     Value     Result    
6. Inspect the insides of the air inlet elbows.
A. Remove the two air inlet elbows that are appropriate for the engine model:
- For 16 cylinder engines, the remove elbows for cylinder heads 1 and 16
- For 12 cylinder engines, the remove elbows for cylinder heads 1 and 12
- For eight cylinder engines, the remove elbows for cylinder heads 1 and 8
inspect the inside of the elbows. Look for residue that is white in color or that is a color from purple to red.
Note:If the intake side of the cylinder head is cracked, some residue may have swirled from the intake valve partly up into the elbow. If the residue coats the entire inside of the elbow, a leaking aftercooler is the problem.     Leaking aftercooler core     Result: One or both of the elbows have residue that is white in color or that is a color from purple to red.
Repair: To locate the leak, pressurize the cooling system to
103 kPa (15 psi). Use a bright flashlight and look through the air inlet manifold. Repair the aftercooler core or replace the aftercooler core.
Result: The elbows do not have residue that is white in color or that is a color from purple to red.
Proceed to Test Step 7.    
Illustration 5 g02910497
(9) Lower edge of the cylinder liner (10) Main bearing cap
Table 7
Troubleshooting Test Step    Value    Result    
7. Pressurize the cylinders.
A. Pressurize each cylinder according to Special Instruction, REHS7138, "New Cylinder Leak Test Procedure Available for 3500 Engines".
B. Check for pressurization of the cooling system. Also check for a loss of cylinder compression.
Note: Usually, a cracked cylinder liner is associated with damage to the liner and to the piston rings. A loss of cylinder compression begins almost immediately.     Cracked cylinder liner     Result: The cooling system becomes pressurized and/or the cylinder loses compression rapidly.
Repair: Replace the damaged parts.
Result: The cooling system does not become pressurized. The cylinder does not lose compression rapidly.
Repair: Proceed to Test Step 8.    
8. Look for internal coolant leaks.
A. Remove the crankcase side covers, as necessary.
B. Pressurize the cooling system to
103 kPa (15 psi).
C. Look for coolant dripping from the lowest edges of the cylinder liners (9) and from the main bearing caps (10) .     Damaged lower cylinder liner seal     Result: Coolant is dripping from the lowest edges of the cylinder liner and from the main bearing caps.
Repair: Remove the cylinder liner and replace the seals.
Result: Coolant is not dripping from the lowest edges of the cylinder liner and from the main bearing caps.
Proceed to Test Step 9.    
9. Check for a leaking cylinder head gasket.
A. Check for combustion gas in the coolant.
a. Attach one end of a hose to the radiator and submerge the other end of the hose into a container of water.
b. Run the engine and observe the end of the hose in the water.
A few isolated bubbles may emerge from