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How Do I Bleed My Yanmar Tractor Fuel System?

We want to help you bleed your tractor fuel system safely and effectively.

If you do not feel that you understand these steps, or can perform them safely, consult your tractor dealer or local mechanic.

First --- if you tried to start your tractor before you bled the system --- OR if you run out of fuel --- you will need to follow all the steps we are giving. This is because you have introduced air through the pump --- that is now in the system.

IF --- you are changing your valve and filter and have not started your tractor --- you can stop after the third step. This is because air has not made it through the pump.

Let’s go through the steps:

(1.) Fill your fuel tank. This adds pressure to the fuel system. Therefore, you can flush air out much quicker.

(2.) Locate the bleeder screws. They are at the top of the fuel filter valve. This is the part that attaches the fuel bowl. Open the left screw at the top (10mm wrench) a few turns and wait for the fuel to come out. Once it stops bubbling, tighten up the screw. Repeat with the right screw. The filter should now be out of fuel.

(3.) Follow the fuel hose up to the injection pump. You will see a small bleeder screw (10mm wrench) on the pump. This is where the fuel line goes into the pump. Loosen it. Now, wait for the air bubbles to completely come out. Then tighten it again. You should be getting straight fuel to your injectors now. Do not over-tighten the bleeder screw. This is a very small screw. It has a hole through it and does not take much effort to twist it off. Some newer units have a spring-loaded push-button bleeder. Follow the same procedure --- just push the button instead of loosening the screw.

NOTE: If you run out of fuel while running the engine. Or if you tried starting your tractor before bleeding the system, you will need to go through step 7