24. SERVICE PROCEDURE 24.9 EVERY 4000 HOURS SERVICE Maintenance for every 50, 100, 250, 500, 1000 and 2000 hours should be carried out at the same time. 24.9.1 CHECK PLAY TO TURBOCHARGER ROTOR Ask Komatsu distributor to check the play ot the turbocharger rotor. 24.9.2 CHANGE ANTRIFREEZE Follow the procedure of 24.2.2 “CLEAN INSIDE OF COOLING SYS- TEM” for draining and refilling the cooling system. 24.9.3 CHECK DRIVE BELT, IDLER AND FAN HUB BEARINGS 1. Remove the fan drive belt. Visually inspect the fan hub for: Freedom of rotation Cracks Grease seal leakage 2. Measure the fan hub end clearance. Fan Hub Clearance mm in.
0.08 MIN 0.003 0.41 MAX 0.016 Replace or rebuild the fan hub if the end clearance does not meet these specifications. 3. Visually inspect the belt for: Cracks Glazing Tears or cuts Excessive wear 4. Visually inspect the idler pulley for: Freedom of rotation Cracked, chipped or broken pulley grooves 5. Measure the idler pulley end clearance. Idler Pulley End Clearance mm in. 0.025 MIN 0.0010 0.250 MAX 0.0100 Replace or rebuild the idler pulley if the end clearance is not within these specifications. 24.9.4 CHECK VIBRATION DAMPER Check that there are no cracks or peeling in the outside surface of the rubber.
If any cracks or peeling are found, contact your Komatsu distributor to have the parts replaced. PC450-ENG 3-80