Oil & Fuel CK30 HST - No Power after 30 minutes under load

[Patches]

Before I did that , I'd pull the line from the tank to the filter and blow some compressed air , gently, back to the tank. If there is some sort of contamination(blockage) at the tank, that will clear it and you'll then know you'll have to pull the tank and clean

 

[VictorW]

You advised that you had the fuel pump replaced. Was that the injection pump or the lift pump? A few members had the lift pump diaphram go bad and then not enough pressure to keep the injection pump supplied fully with fuel. The air in the fuel bowl is what is strange unless it always been there. If you pulled the line from the filter and blew air, that would go through the lift pump first then into the tank. I assume both hoses are good and with no pin holes.

 

[ereilly]

I did have the injection pump replaced several years ago. That issue made the tractor difficult to start and it smoked.

I don't know anything about lift pumps.

Good idea for an easy test to blow air into the fuel line back into the tank. I will try that one. Thanks!

 

[VictorW]

If you follow the line backwards to the tank from the fuel bowl, it will first connect to the lift pump which is connected to the side of the engine block. This pump is used to push the diesel, which is gravity fed from the tank, through the filter and to the IP. This is a small mechanical diaphram pump normally putting out about 4lbs of pressure. The line from this pump then continues backwards to the tank. I wouldn't blow air through the lift pump. You may damage the diaphram. An easy lift pump test but not exactly perfect is to disconnect the line coming from the lift pump at the fuel bowl. Put your finger/thumb over the end of the line and crank the engine over. With light pressure, the fuel will try to spray out. I was able to then push hard enough on mine and stop the flow but again, it's should be around 4lbs pressure.

 

[ereilly]

Vic,

Thanks for that last post with the details on the lift pump. I certainly don't want to damage the diaphragm!. I will try to check this out tomorrow.
Happy 4th!

Ed

 

[Patches]

If indeed the lift pump is between the tank and filter,(mine is not), disconnect the tank line at the lift pump and blow back to the tank; you certainly don't need to make this any worse than it is

 

[ereilly]

Finally got a chance to spend time on the tractor.

I pulled the line from the tank to the lift pump. Fuel came out quickly and I shoved the hose back on. I then took the line off the lift pump. When cranking engine, a small amount of fuel dribbled out. I put my thumb over it and held it while cranking and it developed slight pressure. I only cranked for 3-5 seconds each time. Seemed like low pressure but I am not sure what 4lbs looks like. Should I get some kind of pressure tester?

At this point I don't know if lift pump is supplying adequate pressure or not.

 

[Coyote machine]

I'm not sure if the lift pump is rebuildable. Are there any screws on the pump housing indicating a possibility of a pump rebuild kit maybe existing? Maybe someone who's done the pump replacement in the past can comment on this?
Sounds like you don't have any real pressure at the lift pump, but hard to tell. Didn't Vic say he was able to hold the flow back, indicating more than dribbling fuel?

 

[VictorW]

If I remember correctly, another member had taken their lift pump apart and could remove the diaphram. The problem was that the diaphram is not available as a repair part. You need to buy the lift pump as an assembly.

When I cranked mine over, the lift pump would push out fuel in squirts because of the operating diaphram, and the full diameter of the hose had fuel and would shoot out a few inches. With light pressure from my thumb over the hose, the fuel would spray. If I pushed reasonably hard on the end of the hose, I was able to stop the flow. If it's just trickling fuel, I'd say there is a hole in the diaphram. Pull the pump off, separate the two halves and you'll see the diaphram. It can be reassembled if by chance the diaphram is good but a trickle isn't enough.

 

[VictorW]

Doing some work with my tractor today and pulled the hose off the fuel filter bowl from the lift pump. Cranked it over and definately more than a dribble. It will push out fuel in squirts. Not that much volume but would come out the end of the hose about an inch. I didn't do the thumb pressure test again because it's also hard for me to tell how hard I'm pushing to gauge @4lbs. Even though the fuel runs out of the tank fine, a small piece of dirt may have gotten into the lift pump and damaged the diaphram. I remember several years back when a few members had to replace their lift pump, which is rare, and they talked about putting a screen type filter in the line from the tank to the lift pump.