ELBOW 8S4687 - Caterpillar

Table 1
Required Tools
Part Number Part Name Quantity
1U-5470 Engine Pressure Group 1
FT-1984 Aftercooler Testing Group 1
FT-1438 Aftercooler Gp (DYNAMOMETER TEST) 1 Visual Inspection
Inspect the following parts at each oil change:
Air lines
Hoses
Gasket joints
Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.
Ensure that the constant torque hose clamps are tightened to the correct torque. Check the truck manufacturer's specifications for the correct torque. Check the welded joints for cracks. Ensure that the brackets are tightened in the correct positions. Ensure that the brackets are in good condition. Use compressed air to clean any debris or any dust from the aftercooler core assembly. Inspect the cooler core fins for the following conditions:
Damage
Debris
CorrosionUse a stainless steel brush to remove any corrosion. Ensure that you use soap and water.Note: When parts of the air-to-air aftercooler system are repaired, a leak test is recommended. When parts of the air-to-air aftercooler system are replaced, a leak test is recommended.The use of winter fronts or shutters is discouraged with air-to-air aftercooled systems. Winter fronts can only be used on certain truck models. On these trucks, tests have shown that the engine jacket water will overheat before the inlet manifold air temperature is excessive. These trucks use sensors and indicators that are installed in order to indicate engine operating conditions before excessive inlet manifold air temperatures are reached. Check with the truck manufacturer about the use of both winter fronts and shutters.Inlet Manifold Pressure
Normal inlet manifold pressure with high exhaust temperature can be caused by blockage of the fins of the aftercooler core. Clean the fins of the aftercooler core. Refer to "Visual Inspection" for the cleaning procedure.Low inlet manifold pressure and high exhaust manifold temperature can be caused by any of the following conditions:Plugged air cleaner - Clean the air cleaner or replace the air cleaner, as required. Refer to the Operation and Maintenance Manual, "Engine Air Cleaner Element - Clean/Replace".Blockage in the air lines - Blockage in the air lines between the air cleaner and the turbocharger must be removed.Aftercooler core leakage - Aftercooler core leakage should be pressure tested. Refer to "Aftercooler Core Leakage" topic for the testing procedure.Leakage of the induction system - Any leakage from the pressure side of the induction system should be repaired.Inlet manifold leak - An inlet manifold leak can be caused by the following conditions: loose fittings and plugs, missing fittings and plugs, damaged fittings and plugs and leaking inlet manifold gasket.Aftercooler Core Leakage
Illustration 1 g01134323
FT-1984 Aftercooler Testing Group
(1) Regulator and valve assembly
(2) Nipple
(3) Relief valve
(4) Tee
(5) Coupler
(6) Aftercooler
(7) Dust plug
(8) Dust plug
(9) Chain A low power problem in the engine can be the result of aftercooler leakage. Aftercooler system leakage can result in the following problems:
Low power
Low boost pressure
Black smoke
High exhaust temperature
Remove all air leaks from the system to prevent engine damage. In some operating conditions, the engine can pull a manifold vacuum for short periods of time. A leak in the