2007 L3400 Fuel Pump Issue?

[AustinPower]

Hi there, newbie here.
A few weeks ago my 2007 L3400 (400+ hours) started to shut off after doing some work. Came back a day later, bled the system, seemed to work for a few minutes then started to shut off. Noticed the fuel filter housing had a small crack, so I replaced the fuel filter and fuel filter housing. Note: fuel runs out of the tank just fine, so no clogging issue. Tractor worked for about 10 minutes, then it started to shut off again. It seems to work ok when it's a little colder. I'm in Austin, Tx., so gelling is not an issue. It's 107 out here!
See attached video.
Is this as simple as a fuel pump replacement?
You can hear a difinite click of a switch, but not sure if that has anything to do with it.

Any help is greatly appreciated!

 

[rentthis]

One quick thing to check is your fuel cap. Open the cap and see if it continues to run. The caps vent sometimes get clogged and a vacuum will build inside the tank and cause fuel starvation. Probably not you problem but worth trying.

 

[AustinPower]

I'll try that when I go back out there Rentthis. It's worth a shot as it gets pretty dusty out there. Thanks.

 

[rentthis]

I'll try that when I go back out there Rentthis. It's worth a shot as it gets pretty dusty out there. Thanks.

If that isn't the problem, check the switch under the seat. Sometimes they get out of adjustment and will shut off because you don't weigh enough to keep it down. I don't have that problem. With 400 hours, I wouldn't suspect a fuel pump problem.

 

[Sammy3700]

I second the seat switch or operator present switch under the left side of the seat

 

[Dave_eng]

After watching your video it seems obvious that when you depress the hydrostatic go peal a safety system is shutting down the engine.

Stop focusing on fuel issues and put your efforts into first understanding if your tractor has an OPC (Operator presence controller) and if so the Owners' manual will have a simple test procedure for you to do to make certain it is operating correctly.

The following is from a different model of tractor's manual. The first paragraph seems to describe what is happening to you.

A When you stand up from the seat with the speed
control pedal stepped on or the cruise control switch
engaged (ON), the engine will stop regardless of
whether the tractor is moving or not. This is because
the tractor is equipped with Operator Presence Control

When you stand up from the seat with the shuttle lever
at "FORWARD" or "BACKWARD", the engine will stop
regardless of whether the tractor is moving or not. This
is because the tractor is equipped with Operator
Presence Control system (OPC).

When you stand up from the seat with the shuttle lever
at "FORWARD" or "BACKWARD", the engine will stop
regardless of whether the tractor is moving or not. This
is because the tractor is equipped with Operator
Presence Control system (OPC).

Dave

 

[AustinPower]

Thanks everyone. I'll definitely check out the OPC system, especially the "presence" sensor under the seat. Just curious though, if I let the tractor sit for a while, it seems to work just fine. It's only after a few minutes of use that it starts to shut off. When it first starts to fail, the tractor will be churning along just fine then cuts off.
Thanks again for the tips!

I guess I could always eat more too as a safety measure.

 

[Dave_eng]

Thanks everyone. I'll definitely check out the OPC system, especially the "presence" sensor under the seat. Just curious though, if I let the tractor sit for a while, it seems to work just fine. It's only after a few minutes of use that it starts to shut off. When it first starts to fail, the tractor will be churning along just fine then cuts off.
Thanks again for the tips!

I guess I could always eat more too as a safety measure.

Go to the local scuba shop and buy a diver's weight belt.............

Dave

 

[Russell King]

Good luck with the repair. I too am in Austin. Where is your “there” where your tractor is if you don’t mind sharing that? My tractor is an older L185 and in Liberty Hill area.

I imagine you will get it figured out fairly soon but if you need some help I will be willing to help in person (assuming tractor is local). I don’t have much experience with the safety switches but have pretty good luck making things work again.

 

[AustinPower]

Hi Russell,
I live in Austin, but my ranch is about 25 miles south of Bastrop on Hwy 304 just south of 713. If I reach an impasse, I might hit you up on that offer. Thanks again!
--Efren

 

[eserv]

It is not uncommon for the lift pump to fail on this model tractor,

 

[Russell King]

Check air filter and inlet pipes also.

Will it just sit and idle for long periods? Does it die only when you try to move it?

You may check the fuel flow right at the injection pump to see how it flows there.

Don’t mess with the lines out the top of the pump, only bleed near the injectors. There is something there that gets messed up when the lines are loosened up and the larger nut is not held in place correctly so best to leave them alone there.

 

[AustinPower]

Thanks eserv, I might change out the lift pump just because. To replace, looks like it's just 2 bolts, slide old one out, and new one in? Am I missing anything?

Russell,
It will idle just fine for long periods. It will also work just fine under load for about 5-10 minutes when the tractor hasn't been started for a long time. After 5-10 minutes, once it gets warm, it starts to stall.
I'm not at the ranch right now, but I will follow the line of the lift pump and pull the line right before the injector pump to check flow.

Thanks!

 

[eserv]

Thanks eserv, I might change out the lift pump just because. To replace, looks like it's just 2 bolts, slide old one out, and new one in? Am I missing anything?

Russell,
It will idle just fine for long periods. It will also work just fine under load for about 5-10 minutes when the tractor hasn't been started for a long time. After 5-10 minutes, once it gets warm, it starts to stall.
I'm not at the ranch right now, but I will follow the line of the lift pump and pull the line right before the injector pump to check flow.

Thanks!

Yes, just two bolts and the two fuel lines. If the lift pump is bad the tractor will work almost normal with a full fuel tank and operate like you say yours does when the fuel level is lower. It is the check valve that fails in the pump, they are not built to be repairable.

 

[AustinPower]

Now that I think about it, the tank was full when the tractor seemed to work normal. Now that it's at half tank, the issues started happening again.

Will let you guys know what I find.

 

[old and tired]

...It is the check valve that fails in the pump, they are not built to be repairable.

I have no idea if this might work but could you install a One Way Fuel Check Valve just after the pump? Not sure what a pump cost but $10 check valve would be my first attempt!

 

[eserv]

I have no idea if this might work but could you install a One Way Fuel Check Valve just after the pump? Not sure what a pump cost but $10 check valve would be my first attempt!

It might work. Back in to old days I used to install a check valve on Allis Chalmers tractors to prevent hard starting and we also installed them on the Oldsmobile diesel engines. I don't remember if it is the suction or discharge valve that fails so you might need it before OR after the lift pump https://fittings247.com/product/bosch-fuel-pump-check-valve/

 

[AustinPower]

Figured out the problem. It took the tractor about 2 hours of use before the problem resurfaced.
1. New fuel filter and fuel filter housing. No luck.
2. Taped the seat safety switch to the closed position. No luck.
3. Removed gas cap. No luck.
4. Replaced lift pump. Took forever to remove the bolts. No luck.
5. Checked and cleaned all fuses..my last idea.. No luck.

After all this decided to check out the seat safety switch again. Removed the switch and held the lever in the "closed" position really hard while I drove tractor. Bingo! The switch works at 6pm position, won't work at 5:59pm position. Sprayed electrical contact cleaner inside a small hole in the switch. Tractor works fine now. I'll be replacing the switch anyways.

Lesson learned to those reading, don't think the switch will work with just taping it in the closed position. Hold it firm in the closed position. Worst case, you'll need to figure out which of the 2 out of 3 wires to short together for debug. It's still very weird that the switch only starts to fail after using the tractor a while.

Thanks for the help and advice everyone!

 

[CplILJ]

Replying to this thread as it includes all recent issues I experienced on my similar L4330Dhst yr and model purchased spring of 2021. This forum was (still is) a great resource for me so sharing in case my experience can help someone else troubleshoot.
Shutdown issues presented with the arrival of cold weather. Sputter and come back. My instincts went to fuel. Did find lift pump to be weak, replaced it, issue not fully resolved. Cleaned entire tank and fuel line routings to inj pump. Found press in hose fitting on fuel filter housing loose. By loose I mean could rotate and work out by hand. This is a press in fitting and shouldn't do this. Removed, cleaned, expanded ID of press in diameter with a punch then pressed back in with green locate. Fuel issue finally solved.

 

[CplILJ]

Replying to this thread as it includes all recent issues I experienced on my similar L4330Dhst yr and model purchased spring of 2021. This forum was (still is) a great resource for me so sharing in case my experience can help someone else troubleshoot.
Shutdown issues presented with the arrival of cold weather. Sputter and come back. My instincts went to fuel. Did find lift pump to be weak, replaced it, issue not fully resolved. Cleaned entire tank and fuel line routings to inj pump. Found press in hose fitting on fuel filter housing loose. By loose I mean could rotate and work out by hand. This is a press in fitting and shouldn't do this. Removed, cleaned, expanded ID of press in diameter with a punch then pressed back in with green locate. Fuel issue finally solved.

Next shutdown happened with arrival of serious cold,-20F and colder, while snowthrowing. But this time was as if key had been turned off. No sputter no loss of power. Was very hard to diagnose and troubleshoot as shutdowns didn't have a pattern. But they progressed to develop one. I checked any and all connections or plunger style switches exposed to cold outside of cab. Then as reported in this thread found I could bring tractor back by moving seat switch via bouncing in the seat. Sure seemed like a seat switch issue. Replaced, not resolved. Then I read about this notorious OPC timer. Made sense as all operator activated switches send a signal to it. When issue first started I could bring it back occasionally by pressing clutch in or letting off hst pedal, all operator inputs. But then progressed to input from seat switch and eventually even that didn't guarantee a fix. So would sit for 2 mins and could restart for short time.
Anyways, OPC timer fully resolved issue.
What a relief. I love thus tractor, when it works. Hope this can help someone.