Lubrication & Maintenance/500 Hour/12 Month Checking Air Intake System IMPORTANT: The air intake system must not leak. Any leak, no matter how small, may result in internal engine damage due to abrasive dirt and dust entering the intake system. RG4689 –UN–20DEC88 1. Inspect all intake hoses (piping) for cracks. Replace as necessary. 2. Check clamps (A) on piping which connect the air cleaner, engine and, if present, turbocharger. Tighten clamps as necessary. This will help prevent dirt from entering the air intake system through loose connections causing internal engine damage. Check Clamps 3.
If engine has a rubber dust unloader valve (B), inspect the valve on bottom of air cleaner for cracks or plugging. Replace as necessary. RG7332B –UN–22JAN99 IMPORTANT: ALWAYS REPLACE primary air cleaner element when air restriction indicator shows a vacuum of 625 mm (25 in.) H 2 O, is torn, or visibly dirty. 4. Test air restriction indicator (C) for proper operation. Replace indicator as necessary. Underloader Valve and Air Restriction Indicator A—Clamps B—Dust Unloader Valve C—Air Restriction Indicator IMPORTANT: If not equipped with air restriction indicator, replace air cleaner elements at 500 Hours or 12 Months, whichever occurs first. RG,RG34710,5575 –19–23NOV01–1/1 30-11 021604 PN=148