Oil & Fuel Kubota L4600 ran it out of diesel, emptied fuel filter bowl... won't start...

[glenintenn]

Hopefully I'm missing something stupid.

Ran a 2013 L4600 hydrostatic out of diesel. Figured since the tank had completely bottomed out, I should inspect the fuel bowl and clean it out.

I turned off the fuel cock and took the bowl off.
There was a little bit of filth in the bottom so I cleared that but the filter looked pretty good. I didn't take the filter off... left it on the mount that it sits on.
I put the bowl back on and tightened it up.

Put 5 gal of fuel in the tank, turned the fuel cock back to the on position. Fuel rushed in and filled up the bowl.

Then tried to start.

No dice.

Finally got the owner's manual out and found the bleeder valve ("air vent cock" in the manual). Opened it, turned key to first position (not sure if my unit has an electric fuel pump or not), then tried cranking it. Cranked and cranked. Nothing. It will sputter a time or two after about 20 seconds of cranking but never catches and starts up -- with or without the bleeder valve open.

The tractor is sitting on an incline with the nose down... can't see how that would change anything.
The PTO was engaged (bush hog) when the tractor cut out. I turned the PTO engage switch to off before I got off the tractor when it cut out.

Are there any additional steps to get air out of the line?

What should be checked next?

 

[sea2summit]

99% sure you have air in the system. Manual doesn’t give instructions for bleeding the air after a filter change? You probably need to have that valve open until it pumps solid fuel. If there is air past the valve you may need to bleed it at the injectors.

Not scary or unheard of but it is a chore. And a good chore to know how to do.

 

[glenintenn]

Pretty much what I suspected but have no experience with Kubota diesels to fall back on as I'm a newb on this tractor.

Manual indicates this:

1. Fill fuel tank
2. Open bleeder valve
3. Start and run for 30 seconds

That's it.

Some have indicated that on "newer" (is 2013 new"er"? not-new-any-longer?) models that loosening the injectors may cause damage. Mine has the hex mounts on the injectors-- not sure that indicates anything...

The bleeder valve (#080) seems to seat right at the base of the injectors... see 4600H diagram below...

 

[sea2summit]

Yeah, 80 should get the job done. You got a solid stream of fuel out of it before you tried to crank and you’re sure the filter is full of fuel?

 

[ROUSTABOUT]

The manual says don't run it out of fuel too. So if you don't run it out of fuel you wont have to bleed injectors. That's why it isn't in the book. We have several machines around here. One or two have fuel gauges on them. Never have run out of fuel in them without gauges. See, on that Kubota if you turn the lines at the injector pump you can get it out of time. Then haul to your dealer. They take pump off and send it somewhere. When it eventually comes back they'll get around to trying to get it back together. Best to keep fuel in it.

 

[CobyRupert]

What do you mean if you turn the lines, it gets out of time? How?

 

[glenintenn]

Yeah, 80 should get the job done. You got a solid stream of fuel out of it before you tried to crank and you’re sure the filter is full of fuel?

No... no stream of fuel ... it only mentions that it's an air vent in the manual, not a fuel valve... ?

Probably should replace the o-ring ( 130) just to be sure there's not further air getting into the system

 

[thepumpguysc]

Just LOOSEN the lines AT THE INJECTORS a couple of turns.. and crank the engine until fuel squirts out and tighten.. start engine..

 

[glenintenn]

Just LOOSEN the lines AT THE INJECTORS a couple of turns.. and crank the engine until fuel squirts out and tighten.. start engine..

when you say "at the injectors" you mean the top hex nut (red arrow) which screws onto the injector below it, not the nut down below (I put a red X on the one *not* to loosen, correct)?

do you just to one at a time or all of them at once?

 

[seville009]

https://reliancepowerparts.com/catalog/documents/tech-tips/parts-and-service-bulletins/kubota/fuel-systems/REL-KU2.10-2.pdf

 

[Ed ke6bnl]

On most diesels I will crack open all the lines at the injectors OPEN THROTTLE and crank till I see fuel coming out of the injector line. I like to close them while this is happening (sometimes it will start then) then close them all up and start it (here goes the haters) then a light spray of either. Your tractor though, do as you see fit.

 

[thepumpguysc]

Yes, the arrow is pointing to the lines..BUT..your pointing to the PUMP SIDE of the line.. YOU DO NOT loosen them there EVER, unless removing the pump..
Loosen them AT THE INJECTORS.. ALL AT ONCE..

 

[glenintenn]

Yes, the arrow is pointing to the lines..BUT..your pointing to the PUMP SIDE of the line.. YOU DO NOT loosen them there EVER, unless removing the pump..
Loosen them AT THE INJECTORS.. ALL AT ONCE..

OK. so you're saying I had it reversed. Just asking for ultimate clarification because multiple folks are saying it's do or die on one nut versus the other.

 

[thclimer]

Attached is the bleeding procedure for my TC33D. I think most diesels are similar in that you want to open/crack a fuel line as close to the injector as possible so that once everything is tightened back up fuel can then be sprayed by the injector, see pictures.

Let us know what you find.

 

[thepumpguysc]

Yes Glen, u loosen the lines AT THE INJECTORS..
Never at the pump..
U stand a better than average chance in loosening the top nut(delivery valve holder) on the pump and losing the seal..
The torque on the top nut IS CRITICAL to the operation of the pump..
That’s why I joined this site, there was SO MUCH bad information being passed around that it was doing more harm than good..
And I see I have more work to do.. lol

 

[glenintenn]

Yes Glen, u loosen the lines AT THE INJECTORS..
Never at the pump..
U stand a better than average chance in loosening the top nut(delivery valve holder) on the pump and losing the seal..
The torque on the top nut IS CRITICAL to the operation of the pump..
That’s why I joined this site, there was SO MUCH bad information being passed around that it was doing more harm than good..
And I see I have more work to do.. lol

Well, never to be shy in asking dumb questions... this entire assembly at the bottom of the diagram you were referencing up above is the "injector pump assembly" (020 in this diagram below, red square. no further parts explosion that I can find for that injector assembly) ... is that the fuel pump you're referring to?

This is why I've been confused by "loosen the lines at the injectors" but... "never at the pump". The injectors appear to be "in" the pump assembly then the "Injection Pipe" ( 050 on the diagram above which you commented on) is screwed onto the injector.

Sorry for my slow learning here. I'm a newb disciple of Orange.

 

[thepumpguysc]

The injectors are screwed into the head..w a leak-off line running between them.

 

[thclimer]

Your L4600 looks to have 4 injectors (see crude labeling below). One at a time, open each of the 4-nuts and crank until fuel comes out then tighten and proceed to the next nut, open until fuel flows then tighten, once all 4 have been bled it should start.

 

[jshwhite]

I've dealt with this on a couple of Kubotas. I'm surprised the bleeder valve didn't work. Usually it will fire right up when you do that, but if they're really dry it can take some cranking.

Bleeding the injectors is pretty simple though. Follow thclimer's steps.

Your L4600 looks to have 4 injectors (see crude labeling below). One at a time, open each of the 4-nuts and crank until fuel comes out, then proceed to the next nut, once all 4 have been bled it should start.


View attachment 746606

 

[thepumpguysc]

Again, open them ALL UP AT ONCE..stop cranking the engine once they all start spitting fuel and tighten the steel lines