Yanmar Tractor Fuel Filter Service



The fuel filter is the most overlooked service item on any Yanmar tractor. It is believed that the fuel filter will only effect performance and can not harm the tractor. WRONG! Starving an injection pump for fuel can perminantly damage the pump. The water that is collected by the filter will permionantly damage the fuel injection pump (cost up to $800 new!).

A new fuel filter is cheap insurance against premature injector pump failure. Debris and especially water in the diesel fuel system can dramatically shorten injector pump life. There are several types of fuel filters used on these tractors so your tractor may be slightly different.

Before you start this procedure, fill your fuel tank completely full of diesel.


1 - Shut off the fuel going to the filter either by closing the valve on the filter housing (may be a little difficult to move. Try to wiggle back and forth to free up valve) or use a pair of vise grips and clamp off the hose..

2 - On most Yanmar tractors- Remove the element housing by unscrewing the housing. Remove the disposable filter from the plasic bowl.

3 - Poor out contents of filter and housing into a clean container. Check fuel for excessive water (usually a tablespoon or two). If you see excessive water or contaminants in your fuel you might want to consider changing your filter more frequently.

4 - Remove the filter element from the housing and thoroughly clean the housing with a light solvent such as diesel or mineral spirits. Carburator cleaner or other harsh solvents will cloud over plastic bowls.

5 - Always replace your fuel filter bowl oring with a new one every time you change your filter. A leaking O-ring will cause the tractor to be hard to start and smoke excessively.

6 - Install new filter being sure to install the O-ring in the popper place. Fill filter and housing with clean fuel.and tighten by hand. Do not over tighten!

7 -Loosen the bleeder screw on the fuel injector pump(all Yanmar tractors) , where the fuel line goes into the pump. Let fuel run out until there are no air bubbles. The extra fuel that you put in the tank will put more pressure on the system and make this a lot easier!


8 - If you attempted to start the tractor before COMPLETELY bleeding the air out of the injector pump as described above, you may need to crank engine over (never for long periods of time- which can damage starter) while you have the injector lines at the injectors loose as shown in the picture. Tighten back up as soon as there is just fuel (no air bubbles) coming out of the lines.You may need to do this at each injector.