105931-6251 ZEXEL 9 420 613 590 BOSCH GOVERNOR 9420613590 1059316251

The primary fuel filter should be cleaned, and the secondary (main) fuel filter element replaced, as follows: 1. When the fuel pressure gauge (if equipped) indicates low fuel pressure.2. When the engine has a noticable loss of power.3. Every 500 service hours of operation if the engine is not equipped with a fuel pressure gauge.
Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire. Disconnect the battery (turn disconnect switch OFF) when changing fuel filters.
Do not fill fuel filters with fuel before installing them. Contaminated fuel will cause accelerated wear to fuel system parts.
Close the fuel supply valve at the tank before servicing filters. Open the valve after filter servicing is completed.Cleaning Primary Filter
Use all cleaning solutions with care.
1. Loosen the nut (1) on the filter cover and lower the filter case (3).2. Remove the element (2). Wash the cover and element in clean nonflammable solvent.3. Reinstall the element.4. Install the element and case onto the cover into the case.5. Tighten the bolt.Changing Secondary Filter
1. Unscrew filter element. Throw away the used element. 2. Make certain all of the used element seal is cleaned from the filter base. 3. Coat the seal of the new element with clean diesel fuel.4. Install the filter by hand. When the seal contacts the base, tighten 3/4 turn more.There are rotation marks 90° apart on the filter. Use these as a guide for proper tightening.5. Start the engine and check for leaks. If the engine will not start, prime the fuel system.