RK55HSC Fuel filters

[Melancholy Bear]

Where is the fuel filter air breather screw that the owners manual mentions? Changing both fuel filters tomorrow and the manual sucks. Any tips/instructions for this procedure would be much appreciated. I realize having air in the system will cause major problems, and I'm a bit concerned about that.

 

[RjCorazza]

@Melancholy Bear
Not familiar with your specific tractor, but the manual vaguely describes that the bleeder is on the filter or filter housing itself. Look for likely a bolt or knob on the housing, and try loosening it while the electric lift pump is running (key in run position, engine not started). Close the bleeder after you see fuel at the bleeder without air bubbles coming out.
If there is not a bleeder on the filter or housing, look on the fuel lines prior to the injection pump for bleeder valve(s), usually round knobs.
General : Most recommend NOT pre filling replacement filters with fuel when installing. The empty filter will have to be evacuated of air during the bleeding process, and may take a little time. I personally fill the filter with fuel from a filtered source, being as careful as possible to not introduce contaminants.
If an RK55 owner doesn't come along to offer specific advice, post some pictures of your fuel system so we can see what you have.

 

[Melancholy Bear]

There are two filter housings. The manual does not indicate which has the air breather screw or where it is. I assume it would be on the air separator housing since it is higher in elevation? There is a phillips head bolt on the side of the air separator housing. Would that be it? Here are photos.

 

[ptsg]

Third picture, that small bolt in the middle and top of the filter housing should be the bleeder screw.

 

[Melancholy Bear]

Third picture, that small bolt in the middle and top of the filter housing should be the bleeder screw.

Thank you!

 

[RjCorazza]

I think @ptsg is correct. It's #21 in the attached parts diagram that is labled "breather"

 

[Melancholy Bear]

@RjCorazza Excellent, thank you! And to drain the fuel, I unscrew #25?

 

[Melancholy Bear]

Update to the breather screw: RK mechanic told me that, because it is upstream of the fuel pump, it won't purge air unless you hook up an air compressor to the fuel tank vent hose. He said not to bother with it when changing the fuel filters. Not sure if he's correct.

Has anyone changed the fuel filters who could give me a step-by-step?

 

[RjCorazza]

Perhaps it's a self bleeding fuel system. My Kubota diesel mowers have (2) filters before the lift pump and one after. I bleed them by just leaving the key switch in the run position (engine off) for about a minute or so and it bleeds the air without using bleeder valves.
Hopefully an RK owner here can offer more advice.

 

[kobowski131]

I have replaced my filters several times. First, you close the valve on the pre-filter, unscrew the filter and replace it. You open the valve and turn on the ignition (DO NOT START THE ENGINE) for a few minutes until you hear the fuel pump change its sound, then you have bled the pre-filter. Then you start the engine and let it run for two or three minutes. You turn off the engine. You close the valve on the pre-filter, then replace the fine filter and open the valve on the pre-filter. You turn on the ignition (DO NOT START THE ENGINE) for 5 - 8 minutes until the system is bled, only then can you start the engine.