65517 Mercury NUT, SPEED - FRONT COVER TO COWL

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. Refer to Torque Specifications, SENR3130, "Standard Torque for Constant Torque Hose Clamps" 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 fins of the aftercooler for the following conditions:
Damage
Debris
CorrosionUse a stainless steel brush to remove any corrosion.Note: When parts of the aftercooler system are repaired or replaced, a leak test is recommended.Inlet Manifold Pressure
Normal inlet manifold pressure with high exhaust temperature can be caused by blockage of the aftercooler core. Clean the aftercooler core.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 (Dual 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" under this topic for the testing procedure.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
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 temperatureA large leak of the aftercooler core can often be found by making a visual inspection. To check for smaller leaks, use the following procedures:Leak Test for the Sea Water Cooling System
Test for Water Leaks
Remove the aftercooler core from the engine. Refer to Disassembly and Assembly, "Aftercooler and Aftercooler Core".
Thoroughly clean the aftercooler core.
Plug the fittings of the aftercooler core.
Pressurize the aftercooler core to 240 kPa (35 psi).
Spray the aftercooler core with a mixture of water and a soap solution. Look for air bubbles that form on the aftercooler core.Test for Air Leaks
The bottom opening of the aftercooler must be closed in order to perform the following pressure test. A cover may need to be fabricated in order to plug the opening.
Remove the aftercooler from the engine. Refer to Disassembly and Assembly, "Aftercooler and Aftercooler Core".
Assemble the aftercooler on the bench. Refer to Disassembly and Assembly, "Aftercooler and Aftercooler Core".
Plug the openings of the aftercooler and pressurize the aftercooler to 205 kPa (30 psi).
Spray the aftercooler core with a mixture of water and a soap solution. Look for air bubbles that form on the aftercooler core.Turbocharger Failure
Personal injury can result from air pressure.Personal injury can result without following proper procedure. When using pressure air, wear a protective face shield and protective clothing.Maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.
If a turbocharger failure occurs, remove the aftercooler core. Internally flush the aftercooler core with a solvent that removes oil and other foreign substances. Wash the aftercooler with hot, soapy water. Thoroughly rinse the aftercooler with clean water and blow dry the aftercooler with compressed air. Blow dry the assembly in the reverse direction of normal air flow. To make sure that the whole system is clean, carefully inspect the system.