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

[ereilly]

Tractor has been running fine for months. I was mowing grass today. Ran fine for 30 minutes then gradually lost power. I kept lifting three point, thinking the mower was getting clogged. It would come back up to 540 RPM and run OK for a little while. This got gradually worse until tractor would barely run with PTO disengaged and no load. Temp was fine - right in the marked zone. I blew out the air cleaner and then noticed the fuel bowl had air in it. I bled the air out by switching the fuel filter switch to air until the bowl was full of fuel again. Tractor ran fine for 5-10 minutes, then became weak again. I had one of the bad batch of fuel pumps replaced 4-5 years ago. The only thing I do that really puts a load on the tractor is the brush hog mowing. I have a chipper that seems to work fine but it is not continuous hard work like heavy mowing.

Thanks for any ideas.

 

[jimmyj]

Not really sure what this could be but is your hydro fluid level ok? Is it whining or making any different sounds? The engine rpm's stay the same I assume?

 

[ereilly]

Not really sure what this could be but is your hydro fluid level ok? Is it whining or making any different sounds? The engine rpm's stay the same I assume?

I will check fluid but it is more like starved for fuel. RPMs drop way down. Even in low with PTO disengaged tractor can barely climb hill. When it first begins, pressing clutch brings RPMs back up. This is so weird because it starts gradually with power loss when going up hill or hitting thick patch of grass. Putting in clutch brings RPMs up again, then tractor runs decently then starts losing more and ore power until barely can climb hill.

 

[VictorW]

It's odd that you had air if the fuel filter bowl. Maybe the lift pump diaphram has a hole in it. That pump should only put out about 4lbs of pressure and a pin hole in the diaphram would give you some air and not much fuel through the filter to the injector pump. A hole in the pump diaphram can also leak diesel fuel into the engine. Check your engine oil level. Not sure what year your tractor is but some had a fuel tank cap that wouldn't vent but that shoudn't be the cause for the air. With temps normal and your other findings, it does seem like starving for fuel at some point prior to the IP.

 

[ritcheyvs]

This is a classic symptom of fuel starvation: usually caused by either a fuel line (or tank outlet) blockage, air bleeding into the fuel feed line, a plugged fuel tank vent, or a bad lift pump. The tank vent is unlikely but easiest to check: when you lose power remove the fill cap which would relieve any tank vacuum. Do the checks Vic mentioned and also sniff for diesel smell at the oil fill.

 

[AchingBack]

This is a classic symptom of fuel starvation: usually caused by either a fuel line (or tank outlet) blockage, air bleeding into the fuel feed line, a plugged fuel tank vent, or a bad lift pump. The tank vent is unlikely but easiest to check: when you lose power remove the fill cap which would relieve any tank vacuum. Do the checks Vic mentioned and also sniff for diesel smell at the oil fill.

In addition to the excellent advice above, you might need to drain the fuel tank to rid the system of blockage.

 

[TJP89]

Fuel starvation. I assume you have fuel in the tank right? Don't go by the gauge, they're notoriously inaccurate. I'd drain the tank, make sure it's clean, then check the lines. Refill with good diesel. Then purge the system per the manual. As mentioned, check the cap vent too. See what you have then.

 

[gilbertmsg]

Also check your fuel filter, it could be clogged and needs to be replaced.

Eddie

 

[Atamasco1984]

there have been posts on TBN in the past about fuel tanks getting clogged with plastic shavings in the fuel tank from when the Tanks were made and drilled. something to look for.

 

[ereilly]

Thanks for all the advice.

Fuel filter and air filter are clean. There is plenty of fuel.
No diesel in the oil that I can tell. Seems slippery and correct smell.

Tried running with fuel cap loose and tractor still loses power.

I will try to remove hoses and drain the tank and refill with fresh fuel.

Thanks again. I will report back in a a few days when I get time to work on it.