Newbie fuel level question

[Alfred_2345]

I have a new to me L3901 and not a lot of experience on tractors or diesel equipment. I was running the tractor yesterday and headed for the "barn" as soon as it hit the Empty mark as I didn't want to push it.

How much "reserve" is in the fuel tank when the fuel gauge is directly on the Empty mark? I checked the operators manual and couldn't find anything.

Also, how bad is it to run out of fuel? The op. man. just says that I would have to bleed the fuel system and doesn't have any other warning. I changed the fuel filter and cleaned the separator when I got the tractor and it wasn't that bad to bleed. I was under the impression that running a diesel dry could damage the engine (injectors, fuel pump?). If it is only having to follow the same bleeding procedure as when changing the filter, that's not too the end of the world.

 

[fried1765]

I have a new to me L3901 and not a lot of experience on tractors or diesel equipment. I was running the tractor yesterday and headed for the "barn" as soon as it hit the Empty mark as I didn't want to push it.

How much "reserve" is in the fuel tank when the fuel gauge is directly on the Empty mark? I checked the operators manual and couldn't find anything.

Also, how bad is it to run out of fuel? The op. man. just says that I would have to bleed the fuel system and doesn't have any other warning. I changed the fuel filter and cleaned the separator when I got the tractor and it wasn't that bad to bleed. I was under the impression that running a diesel dry could damage the engine (injectors, fuel pump?). If it is only having to follow the same bleeding procedure as when changing the filter, that's not too the end of the world.

The simple answer to running ANY diesel out of fuel is:
Just don't do it!

 

[ken erickson]

I have a L2501 which being in the same "family" (l2501, L3301, L3901) will have the same 10 gallon fuel tank as your L3901. I have not run mine "dry" so I can not answer what the reserve might be when your needle hits the empty mark but suspect there might not be a reserve!

I do have the feeling that Kubota engineers did not take great pains to calibrate the fuel sending unit with the fuel gauge . When I hit the half full mark on my L2501 I have used more than 5 gallons, probably closer to 6 or 6 1/2. I am putting fuel in when I hit the 1/4 full mark!

Correction!!!! I checked the spec's. Your fuel tank looks to be 11.1 gallons

Congrats on your new to you L3901!

 

[Biker1mike]

Best to head to the barn at the 1/4 mark ! If I park the tractor and it has 3/4 a tank I will top it off.

 

[GeoHorn]

Running ANY vehicle with a pressurized fuel system (not carbureted/gravity-feed) completely out of fuel is not good …and any fuel-injected vehicle is worse.

However, my Owners Manual states that the Red Fuel Warning lamp will illuminate when the fuel tank drops to Two Gallons remaining. When I bought my M4700DT used…. I decided to see if that function actually worked…and YES…it did. ** 17-gallon tank…red warning light illuminated…15 gallons filled the tank.

Hope this helps.

** The fuel warning light actually serves two purposes… Low Fuel AND alternator/charge system warning. The $#$%@# Previous Owner knew the alternator was inoperative when he sold it to me….so he REMOVED the warning-lamp socket and tossed it in the trash…thereby assuring any potential buyer they would not discover the alternator failure until after taking possession. (Yep…I failed to take my volt ohm meter with me for the pre-buy inspection and the new battery installed did not perk-up my curiosity. My bad. When I discovered the bad alternator I also discovered the missing red warning lamp socket…so ordered the part from Kubota, installed it, and then checked it for function. It is accurate.)

 

[Alfred_2345]

Best to head to the barn at the 1/4 mark ! If I park the tractor and it has 3/4 a tank I will top it off.

Thanks for the feedback. I am trying to learn so would you explain your reasoning?

 

[nbryan]

Best to head to the barn at the 1/4 mark ! If I park the tractor and it has 3/4 a tank I will top it off.

I wait until my 7 us gal B2650 tank is at 2 or even 1 "bars" on the fuel gauge before filling, under 1/4 tank, so my 20L diesel jugs will empty into the tank completely. At one bar there's still about 1 1/2 gallon in the tank according the the capacity spec of my tank, given how full 20L added makes the tank.
Not sure what "empty" means on your gauge but there's always quite a bit of fuel in there after the gauge shows "E".

 

[Biker1mike]

Thanks for the feedback. I am trying to learn so would you explain your reasoning?

Sure. This is just my opinion.
I do not trust my gauge and would rather leave a larger margin of error instead of running out going up the hill.
The 3/4 and fill is so I always know the tractor has plenty of fuel and I can just jump on and go. I am not a daily user and a full tank is less likely to get condensation in it.
I also check the oil and hydraulic levels often just to make sure.

 

[NCL4701]

Agree with others. 1/4 tank means add fuel at next reasonable break/stoppage. Mine has 13.5 gallon tank. When the gauge shows 1/4 tank I empty a 6 gallon can of diesel into it which returns the gauge to Full. That equation doesn’t balance. So I don’t much trust the gauge to be completely accurate. It’s better than the “stick in the tank” method we use on our antique gassers but it’s a lot less accurate. And an off road machine isn’t somewhere in the general vicinity of level at all times like a road vehicle. I’ve run out of fuel running tractors when they had a couple gallons left in the tank but the orientation of the machine had it all bunched up somewhere other than the fuel pick up. If I’m changing the filter in a climate controlled shop, I don’t mind bleeding it. If I’m down in the woods somewhere subject to the weather of the moment, I prefer to not have to walk out to get a fuel can, get the Mule to run it back down to the tractor, bleed the system, drive one vehicle home, then walk back down to get the other vehicle. Or worse, carry a 6 gallon can of diesel a mile or so to refuel and bleed the system. It just ain’t worth it to let it run out.

That, and while gas is a solvent, diesel is a light oil. So at least on some diesels, fuel system components are counting on that oil for lubrication. I’d prefer the pumps not run dry unless it’s unavoidable.

I could be totally wrong about all that, but that’s what I do and why.

 

[Bmyers]

My fuel gauge stays on full for extended period of time and then quickly drops.

As Biker1mike does, I too fuel mine at the end of the day and try to leave it with a fuel tank. My understanding is that a full tank is less likely to build up condensation when temp changes.

 

[Trustable]

Im not sure if yours has a digital fuel gauge or analog. I have an l2501 (same family) with analog and (like ken above) the reported level is never correct. Its not off by a huge amount (maybe a 2-3 gallons it seems) but I definitely would not let it get below 1/4 of a tank just in case. Just something to keep in mind. I am glad you made this post though, I had no idea it could possibly do damage or require extra steps if you let it run dry.

 

[mcfarmall]

I top off at the end of every work day. I don't understand why people run out of fuel in their equipment. Maybe they enjoy being stranded on the side of the road or out in the field, perhaps they need content for the YouTube channel...I don't know.

 

[NCL4701]

My fuel gauge stays on full for extended period of time and then quickly drops.

As Biker1mike does, I too fuel mine at the end of the day and try to leave it with a fuel tank. My understanding is that a full tank is less likely to build up condensation when temp changes.

I’ve actually experienced the condensation thing, although with a 250 gallon fuel oil tank not a tractor fuel tank. Went through the summer with very little oil in the oil tank for the furnace and got a mess of water in the tank. Went from changing the filter once a year and nozzle about every five years to three filters and two nozzles a year. Tank rusted out after 25 years and when they changed it they got about 5 gallons of water out via their system that pumped out the oil in the tank, filtered it, and separated the water before pumping it back into the new tank. Now with the new tank we’re back to one filter a year and new nozzle about every five years whether it needs it or not. I now make sure the fuel oil tank is full or close to it at the end of the heating season.

Plastic tanks are better at resisting condensation and my tractor lives in a climate controlled building but I don’t care to deal with condensation to any degree with a common rail engine.

 

[fried1765]

Thanks for the feedback. I am trying to learn so would you explain your reasoning?

Simple: It is extra work to bleed, and get restarted!
Occasionally.... MUCH extra work!

 

[MapleLeafFarmer]

I have a L3301 and the first 1/3 of the tank takes forever for the gauge to move off full.

The last 1/3 of the tank goes very very quickly. In less than 2 hours I burn off the last 1/3 of the tank!! so take extra care when the gauge says only 1/3 left to make sure I am near my shop or a jug of diesel.

 

[Fordtech86]

It’s a common rail engine, you don’t want to starve the hp fuel pump for fuel or it can get expensive quick! Plus side is it’s fairly easy to bleed the fuel system on one, should self bleed just by cranking it…

 

[old and tired]

My fuel gauge shows empty when it's half full. I can put in 5 gallons when it's "empty"... I would double check to see if your gauge is working correctly. I can work for 4 hours once I'm empty!!!!

I've ran out of fuel a couple of times but I got a simply tractor, thankfully!!!

 

[retired farmer]

Don't ever get below 1/4 or so with my 3301 so I have never ran out of fuel. Not sure if I would have to go through a bleeding process or not, but I will say that when changing filters I never have to bleed the system. It just takes a few more rounds to start.
rr

 

[The Evil Twin]

Best to not run anything out of fuel. The fuel cools and lubes the pump. Once it hits ¹/4 I get to a stopping point and fill er up.

 

[North Idaho Wolfman]

One real downside to running the tank completely out is the amount of crud in the bottom of the tank.
You really don't want any chance of running that through any part of the fuel system!