9540 bogs under load but idles

bsamot69

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Equipment
M9000
Jul 31, 2018
49
0
6
Grapeland, Texas
My tractor and I, m9540, are out in a field with cube cart. The situation: start move forward and after say 30 seconds loses power. Stop and idles okay. Very little fuel in inline fuel filter. Shut off tractor fills up with fuel. Took off separator housing removed some trash at inlet elbow reassembled same problem. Also replaced fuel filter, spin on one. Try blowing through fuel supply hose and it is restricted can't hear bubbling in tank. Is this hose plugged or restricted causing this? I look try to see where it attached on tank and I think I have to drop the tank to replace ? Is there a screen in tank ? Expedited response will be greatly appreciated.
 

Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
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Several yrs back I experienced a similar situation with a M4900. The local Kubota dealer service manager advised me to check for clogged screen in the fuel shut off valve in water separater filter housing. I cleaned clogged screen & engine problems were solved. Another option is fuel tank not venting correctly.
 

Russell King

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Start taking fuel lines off at convenient locations to see where you have flow. Replace line as needed or resolve any other issue you find.

If the tank is steel it may have rusted and that is clogging up system. If the tank is plastic assume you have algae growth and treat the fuel system for that


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SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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Before anything else, try running with the fuel cap off and a rag stuffed in the filler neck. That will tell you f the cap vent is clogged.

Both my M's have metal saddle tanks. Not sure what yours has because you don't state the year.

Sounds to me like fuel starvation
 

JerryMT

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Kubota M4500, NH TD95D,Ford 4610
Jun 17, 2017
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The Palouse - North Idaho
My tractor and I, m9540, are out in a field with cube cart. The situation: start move forward and after say 30 seconds loses power. Stop and idles okay. Very little fuel in inline fuel filter. Shut off tractor fills up with fuel. Took off separator housing removed some trash at inlet elbow reassembled same problem. Also replaced fuel filter, spin on one. Try blowing through fuel supply hose and it is restricted can't hear bubbling in tank. Is this hose plugged or restricted causing this? I look try to see where it attached on tank and I think I have to drop the tank to replace ? Is there a screen in tank ? Expedited response will be greatly appreciated.
Classic case of inadequate fuel delivery. The question is why. The fact that you can't blow through the lines is the key. Start at the tank outlet and proceed through the fuel delivery system to the IP, looking for a blockage. Check the filter head also for internal blockage.
 

Bulldog

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Equipment
M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
78
48
Rocky Face, Georgia
May have trash in the lift pump.

I second checking the vent. I used to have a bad problem with mine getting plugged.
 

SidecarFlip

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May have trash in the lift pump.

I second checking the vent. I used to have a bad problem with mine getting plugged.
I know the metal fuel cap on my M9 has a small breather hole in it. The 105 is similar. I'm extremely careful when I fuel either not to allow any trash to get in the tanks.
 

RCW

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Jerry mentioned the filter inlet. Not familiar with them, but I remember a couple guys saying an elbow or something like one getting plugged with hay, etc. on bigger tractors.
Vent was another thought like the guys mentioned.


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Last edited:

coachgeo

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This is also a classic sign of an air leak.... after checking the fuel cap off thing to see if you have a vent issue...... plumb in a temporary 12v fuel pump as close to the tank as you can and PUSH fuel to the IP. If all the sudden things work..... then you have an air leak....

You might even see fuel being pushed out in the spot air is getting sucked in. NOT always though. Sometimes you get a flap in a rubber fuel line internally.... that during vacuum / normal arrangement, the flap flips open sucks air in from hole below it...... but when you put her under fuel pressure instead.. the flap is forced closed and no fuel leaks out.
 

SidecarFlip

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This is also a classic sign of an air leak.... after checking the fuel cap off thing to see if you have a vent issue...... plumb in a temporary 12v fuel pump as close to the tank as you can and PUSH fuel to the IP. If all the sudden things work..... then you have an air leak....

You might even see fuel being pushed out in the spot air is getting sucked in. NOT always though. Sometimes you get a flap in a rubber fuel line internally.... that during vacuum / normal arrangement, the flap flips open sucks air in from hole below it...... but when you put her under fuel pressure instead.. the flap is forced closed and no fuel leaks out.
Interestingly, I've had that happen with hydraulic brake hoses on vehicles. When they get old, they 'flake' inside and restrict the flow of brake fluid, causing the disc brakes to drag. Only happens on disc brakes because the brake design relies on the minimal pressure of the puck seals to back the pucks off to allow the pads to not drag the rotor. Drum brakes have return springs that overcome that return issue.
 

Bulldog

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M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
78
48
Rocky Face, Georgia
I know the metal fuel cap on my M9 has a small breather hole in it. The 105 is similar. I'm extremely careful when I fuel either not to allow any trash to get in the tanks.
My 9000 doesn't have a vented cap. The tanks are vented thru the frame the hood mounts to. It has a vent hose off either side.
 

SidecarFlip

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M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
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My 9000 doesn't have a vented cap. The tanks are vented thru the frame the hood mounts to. It has a vent hose off either side.
Mine don't and I know because I had to replace the right side saddle tank because when it was new, the drain bung was leaking so my dealer got a new tank and I installed it myself.. Only thing in the right side tank is the sending unit for the fuel level. No tank vent. Having said that, could be one in the left tank as I've never had that one off. My cap has a small hole punched in the side that I would presume is the vent. Metal cap. Never had a fuel starvation issue and both of mine are always operating in a hay chaff enviroment. Kind of wish I could install a JD style reverse flow fan. Cleaning the radiator numerous times a day gets tedious.
 

D2Cat

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Flip, have you actually checked with Kubota to see if the have a reverse flow fan for your engine?

I got a V2203 engine out of a Reefer for my skid steer. I had to get a reverse flow fan for it so it would push the air out the back of the skid steer to the radiator. That was not a problem.
 

Bulldog

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M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
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48
Rocky Face, Georgia
Mine has a vent for each tank. When the right side would get plugged up it would hardly take fuel in from the left tank. When it was being filled the left would be full and the right side still empty. Clean out the tubes and all was good again.
 

lugbolt

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ZG127S-54
Oct 15, 2015
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My 9000 doesn't have a vented cap. The tanks are vented thru the frame the hood mounts to. It has a vent hose off either side.
So is the 8540/9540. Same setup, different tractor but they vent the same.

EIther vent problem or line problem. Or pickup problem. Have seen many over the years with algae and whatnot in the lines, pickup tube, pump inlets, filter housings, etc. Doesn't take much.

I pulled a carb apart earlier from a Kawasaki Mule....had a spider INSIDE the carb bowl. Go figure. Now if I were a spider, I'd sure hate to crawl into something that has gasoline inside of it.