Well, it didn’t actually die, but sputtered and stumbled this morning and wouldn’t start. Been starting since 2006, so it was a surprise. Plenty diesel. Air cleaner clean enough. Must be the fuel filter, and I had one, so we changed it. Still won’t start, so I’m thinking air in the lines and I need to bleed the system.

And I don’t know how to do that. So…who has bled the fuel system on a Kubota RTV 900, and how did ya do it?

I don't know much about diesel's, however i believe you loosen the injector lines (1 at a time i think )at the cylinder head and crank it to bleed and also see if you have fuel to the injectors. process is pretty much the same across diesel's....

I found this thread that may help you as well.
https://www.orangetractortalks.com/forums/threads/kubota-rtv-900-cranks-but-wont-start.36872/

Crack closet to pump to get air out from pump to rail. Then crack farthest to bleed air from rail. Most common starting issues with be the lift pump(feeds injection pump). Then injectors or injection pump.

I thought I had at least 4 boxes, could only find 29 but they're urs if u want them

Couldn’t fix it myself. Some sort of fuel supply thing. Took it to Waco to the Kubota place. This is gonna hurt the pocketbook.

Just think of all the years you got reliable service out of your machine 603. Remember, it’s a machine, they all eventually break down.

^ ^ yep, anything mechanical will fail sooner or later.

ouch, it's gonna hurt ... my guess is going to be fuel pump or injector pump. Was there any water in the fuel filter when you changed it out?

I had a horrible diesel leak on mine a couple years ago (long story) where the injector lines routed up to the injectors. I took all the lines completely off and replaced the little ceramic washers at the injectors. I thought I would have all sorts of air in the lines upon reassembly. I got my wife to crank the engine while I used an open end wrench to bleed the lines, within a minute it smoothed out just fine. I have to do the same thing every time I replace the fuel filter on one of my smaller L series tractors.

I recently replaced all fluids and filters on the Kubota 4400DL tractor. There’s a fuel shut off valve, so all I had to do was fill the filter bulb with diesel, screw it into place, turn the valve back on and fire it up. So easy.

The RTV filter is in an awful place. Hard to get to, but we got it done, and the filter was full of diesel. We bled the system but that rascal just wouldn’t start. Gave up finally and took it to the doctor. It’s an 06 model and I haven’t done much of anything to it, other than fluids and filters. That’s 15 years of trouble free service. Hard to beat that. I think the RTV is a Kubota tractor that doesn’t look like a tractor. It’s that tough.

I told the service guys what the problem appeared to be, and said fix anything that needs fixing. I won’t cry over the cost. This thing is the wife’s machine, and if they take too long to fix it, I’ll sic her on them. When she gets her Irish up, it’s scary.

Red headed Irish woman? That may be some serious anger.

keep us posted on what the cause is and the fix.

I've owned a couple of older RTVs (used) and have done minimal other than normal service. They are relatively easy to work on but trouble shooting can be a pain, (especially on used ones that you don't have any history, like mine).

Buddy had a Polaris diesel that did that. We tried everything in the book and finally decided to say eff it. Took a rag and poured a little gasoline on it, shoved the rag into the air filter area, hit the starter and it fired right up. It sputtered for about 5 seconds then smoothed out and ran fine after that. That was a couple of years ago and no problems since. YMMV

I didn’t mention that we tried something I found on a Kubota website, which was to spray diesel vapor into the air draw (after removing the air filters). That did cause the RTV to run a bit, though not well, and not for long.

As soon as I find out what the problem was, I’ll let everyone know.

Used ether many times on big old diesels but I wouldn't on a newer Kubota

The Kubota service guy called and spoke to the wife. It seems that the diesel tank (06 model RTV) was corroded inside (I thought it was plastic) and the diesel itself was bad (fungus of some sort is what the wife said). That combo managed to ruin the fuel pump, which is on order and should show up by Monday.

The fuel tank was removed, cleaned, and can be reused, they say. Gonna cost me about $600. When I go to pick it up next week I’ll get a more detailed rundown on what happened. Getting details filtered through the wife leaves a bit to be desired.

It's algae and it happens with biodiesel

If you pull from a bulk tank treat it with power service clear diesel or the problem will return

I just ordered some. Thanks.

Sounds like it'll be up and running soon.

My wife is pacing up and back. Without the Kubota, she’s lost. She calls it her “little dump truck”. Honestly, we use that RTV all day, every day. And it’s been good that this thing has run, with little maintenance, for 15 years. That’s amazing.

I tried to use this downtime as a lever to suggest we get a new one, but she ain’t having any of that. And besides, the Kubota place is almost sold out. They had no RTVs and were down to one new tractor on the lot. Like with trucks, the supply chain has slowed to a crawl.

After almost having heat stroke trying to restart my old International in the middle of a field in July I called the dealership. They told me to crack 3 of the lines open leaving one closed. Reverse of what I was doing. It worked.

I would wonder why the fuel filter didn’t stop the debris.

Can’t believe you are getting a fuel pump and all that labor for $600.00. Thought sure the pump would be 4 digits by itself.

Tbar, my guess would be its the "lift pump" which feeds the actual injection pump. They are only about $150 and mechanical so I'm not sure how it died, unless the spring or seals went out. The labor of pulling that tank and cleaning it is worth $600.

Well, if $600 fixes it I'd say that isn't too bad at all with all the trouble free years you've gotten out of it.
I hear many good things about these buggies and their diesel is a little beast according to everyone I know that has or has had one.

Final tab was $881.00, but it runs good now. All new filters too. Still as dirty as a hog in the mud.