Fuel Filter ? How to Replace?

[Andrew Benjamin]

Can anybody direct me to the specific instructions/procedure to replace the fuel filters on my H31? I hear people telling me to bleed the system but I have no idea how to do such a thing. I have seen a filter close to the fuel tank and maybe another on the engine, are these the only 2? Thanks

 

[Steve Dion]

Probably.

Andrew:There are probably only the two filters. The one near the fuel tank is your "primary" filter. The one on the engine is considered the secondary filter. Some owners go so far as to add a second "primary" filter. These primary filters are used to trap sediment and seperate water from the fuel. The engine filter "secondary" is just for sediment.I assume that you are going to replace both filters (good idea). One method is to have a enough diesel fuel to refill the primary filter before you replace it. This eliminates pumping the thumb pump on the engine for several minutes.1. Remove/Replace the filters.2. Open the bleed screws on the engine. The bleed screws are bolts with phillips head screw slots. I think that they are the only ones on the engine that are like this. 3. The pump to bleed the engine is on the starboard side of the engine. It is difficult to find, but I think it is just aft of the dip stick. Keep pressing the thumb pump until fuel start comming out of the first bleed screw. Once it starts leaking, tighten it up.4. Keep pumping until fuel comes out of the second screw (I think that this one is at the secondary filter). Once it starts leaking, tighten it up. At this point with both filters full of fuel and the line bled, you are ready to try to start your engine. When you try to restart the engine, be sure to close the raw water intake. The reason to do this is incase the engine does not start right away, it will not flood the engine with water. As soon as the engine starts you should open the raw water intake. Check your engine for leaks, be careful when checking the engine. Things can get caught in the whirling belts and pullies very easily.NOTE: You should have a oil absorb rag under the engine when you do this to capture any fuel that may spill into your bilge.

 

[Paul Akers]

But first...

...I have found that if I close the shutoff valve on the fuel line at the fuel tank before I begin the whole operation that the fuel in the line will not seep back into the tank. This will make bleeding the line a lot easier. Just remember to reopen the fuel valve when you begin to bleed the system.

 

[Greg]

Add a squeeze bulb

I added a "squeeze bulb" (like on a traditional outboard gas tank line) to my fuel line between the tank and the primary filter. It makes bleeding the line much faster, no need to rely on the fuel pump lever.

 

[Mark Waggoner]

And don't forget the NEW washers

I suggest that you go to the diesel forum and check out the questions and replies about small but troublesome leaks following any adjustment of the bleeder screws. I learned a lot there and finally understand why my secondary filter always had a drop a two to leak, no matter what I did. There are a lot of posts and most have pretty good insights. Rule one is to always, always replace the bronze washers if you even touch any of the bleader screws or "banjo" connections.