MAINTENANCE Item 12 Fuel Filters Spin-On Filters Install new spin-on primary and secondary fuel filter elements on vehicle engines every 15,000 miles (24,000 km) or every six months, whichever comes first. See Figure 17. One method of determining when filters are plugged to the extent that they need replacing is based on the fuel pressure at the cylinder head fuel inlet fitting and the inlet restriction at the fuel pump. In a clean system the maximum pump inlet restriction should not exceed 6 inches of mercury (20.3 kPa). In a dirty system it must not exceed 12 inches of mercury (41 kPa).
At normal operating speed and with the standard .080 inch restriction fittings, the fuel pressure is 55 – 70 psi (375 – 483 kPa). Change the fuel filters whenever the inlet restriction at the pump reaches 12 inches of mercury (41 kPa) at normal operating speeds and whenever the fuel pressure at the inlet fitting falls to the minimum fuel pressure of 6 inches of mercury (20.3 kPa). Figure 17 Spin-On Fuel Filter Locations Install new spin-on filter elements on non-vehicle engines every 150 hours. Replace spin-on filter elements immediately if plugging is indicated, regardless of mileage or hour intervals. NOTE:
Filter change intervals may be shortened to conform with established preventive maintenance schedules, but should never be extended. Item 13 Water Pump and Coolant Inhibitor Element Check the water pump and the coolant inhibitor element. Fuel Pro® 382 Filters Install new Fuel Pro® 382 primary fuel filter elements when the fuel level in the see-thru cover reaches the top of the element or after one year of service, whichever comes first. Water Pump Drain Hole The water pump drain hole should be inspected every 6 months to make sure it is open. A small chemical build-up or streaking at the drain hole may occur. This is not an indication 68 All information subject to change without notice.
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