CORE ASSEM. 6N9963 - Caterpillar

Inspect/Check Radiator Fins
Check the radiator fins for debris. High pressure water is an excellent way to clean the debris out of the radiator fins. If necessary, use a light bulb behind the radiator fins to see if they are completely clean.Refer to Know Your Cooling System, SEBD0518, for more detailed information on cleaning your radiator fins.Inspect/Check Aftercooler System
A hose failure or significant system leak will cause a large drop in boost pressure and power. The engine can be operated at this power level long enough to reach a safe stop or repair area. Sustained operation under this condition should be avoided.
Inspect the front of the air-to-air aftercooler. Examine core fins for external damage, insects, dirt, debris, salt, corrosion, etc. Use a firm stainless steel brush and soapy water to remove dirt, debris, salt, etc. Depending on your findings and operating environment, the maintenance interval for cleaning the air-to-air aftercooler may be more frequent.A slight reduction in power or response, or a small increase in exhaust temperature, may indicate a small air leak in the charge air cooler core or piping. Inspect all air ducting and gasket connections at each oil change. Constant torque hose clamps should be secure. Tighten these clamps until the spring is at least partially compressed.Inspect all welds for cracks. Check the mounting brackets to ensure they are secure and in good condition. Whenever air-to-air aftercooler parts are repaired and/or replaced, a leak test is highly recommended. Refer to the service manual or consult your Caterpillar dealer for the correct procedure to use when performing a leak test.Inspect/Adjust Belts
Inspect the condition and adjustment of alternator belts and fan drive belts.Inspect all drive belts for wear and replace if they show any signs of wear.If one belt in a set requires replacement, always install a new matched set of belts. Never replace just the worn belt. If only the worn belt is replaced, the new belt will carry all the load, as it will not be stretched as much as the older belts. All the belts will fail in rapid succession.If belts are too loose, they vibrate enough to cause unnecessary wear on the belts and pulleys. If belts are too tight, unnecessary stresses are placed upon the pulley bearings and belts which might shorten the life of both.1. Inspect the condition and adjustment of alternator belts and fan drive belts.2. To check the belt tension, apply 110 N (25 lbs) of force midway between the pulleys. Correctly adjusted belts will deflect 13 to 19 mm (1/2 to 3/4 inch).Adjust Alternator Belts
3. To adjust the alternator drive belts, loosen mounting nut (1) and adjusting bracket nut(s) (2).4. Adjust the alternator in or out by either tightening or loosening adjusting nut(s) (2), as required, to obtain the correct adjustment.5. Tighten nuts (1) and (2).6. If new belts are installed, check belt adjustment again after 30 minutes of engine operation. Replace belts in matched sets only.Adjust Fan Drive Belts
1. To adjust the fan drive belts, loosen mounting bolts