Kubota 2000 M4900 engine problem(s)

[tstex]

Here's a few more updates and some sensible tips from one of the dealer mechanics.

First, the contaminate was just water. They tested the other 4 fuel injectors and said they call came back w a "weak-rating". So they're replacing all 5 of them, these 4 and of course the broken one.

Next, the mechanic stated that many times if you do not run your tractor daily or quite often, and at the the same time leave the tank 1/2 empty or less, condensation can form inside the tank. He said to top-off the tank as often as possible especially when you're going to be gone for any extended period of time. The same w the 5-gal diesel containers. He also said to make sure you check [and empty] your glass fuel filter canister if there's any water inside. In the instance with my brother, his wife [a country girl, my bro & 5 other siblings are from the city] ran the tractor and ran the fuel level down real low, going up and down slopes...probably stirred up some XXXX that was injected into the fuel system...

Going to cost him $1100-$1200 in labor $200/injector...the injectors are on order and like anything else these days, might take awhile...**** pandemic gets you coming and going...

Hope this helps someone....anything else of consequence that surfaces, I'll post back.

thank you guys,
tstex

 

[MHarryE]

Don’t know the filtration on your tractor but my Kubotas increase filtration with $$$ of the tractor. My M7 has 4 filters including coarse and fine water separators. The second water separator has a sensor (very basic - float that floats on water but not on fuel rises up and make contact when water in the bowl reaches a certain level). I have water separators on my 2 pumps and go through a lot of fuel, but water is still a problem. Two weeks ago my M7 engine derate, showed an error code “Low fuel rail pressure”. Indicator never showed, no water visible in the bowls of the 2 separators, but changing the element on the second got me back to full power. 285 hours since last change - book recommends changing every 400 hours.

Story on water in fuel. At Cat I had a customer in Saudi Arabia with 47 of one machine in my group. Failed injection pumps on 19 of them. Pictures they sent showed internal injection pump parts rusty - parts that should be living in diesel fuel. Had locals do investigation. Customer was using low price/low quality fuel smuggled at night from Iran. No way to stop that and a customer that can buy 47 machines of one model - and who knows how much other Cat equipment - gets treated well. So we developed a special “Middle East” second fuel separator, which involved an additional electric lift pump, to accommodate customers in the region. Fuel smuggling was so common we made it standard equipment for units sold there and retrofitted everything already sold.

 

[tstex]

Thank you MHarry...My brother has a M4900 Kubota, bought 2000 new, and I have a M5400S, bought 1995 new. Do you have any recommendations on fuel filtering devices that one can retrofit for our tractors? As of now, our sole line of defense is a fuel filter/bowl on the tractor.

In Minn, you have much greater temp swings as opposed to SE Texas. Are there any fuel additives that help? I like the idea of topping off the tank bc that does indeed eliminate condensation. However, I would also prefer something w in the fuel system that could indicate water is present. if possible. Anyone that has a suggestion would be appreciated.

Thanks
tstex

 

[Tx Jim]

My advice from living in Texas operating tractors for over 50 yrs especially on Kubota & Ford tractors equipped with water seperater filter is check this WSF every time you check engine oil level. If water is present clean separater, drain water from tank & add fuel conditioner with biocide. As previously mentioned keeping tank full helps eliminate condensation. I've had water in fuel on all 3 of my tractors fuel systems due to faulty fuel storage tank with no adverse affects. I just correct problem by removing water then continue to cut/rake/bale hay.

On the other hand my neighbor with a M8560 tractor that has common rail fuel system got water in his tractors fuel tank. A fungus grew in the water & local Kubota dealer had to replace IP & inj's for high $$$$$$

 

[tstex]

THanks Jim / what type of biocide do you add that isn't a large portion of water itself and how much per gallon of diesel?

 

[MHarryE]

Adding an additional water separator is not straight forward. Injection pumps often have a lift pump feeding them. They might not be able to handle extra restriction. And adding a separator between the lift pump and injection pump may cause problems. The case I described required replacing the original lift pump with one capable of handling the added restriction. The filter media needs to be capable of withstanding the lift pressure. And water separators are capable of separating about 95% of the water so some is still going to get through, hopefully not enough to damage the system, the reason to use good fuel and do things like keep the fuel tank filled reducing the condensation problem. I have 2 100 gallon tanks on a trailer each having a Goldenrod water separator. Despite keeping a limited amount of fuel on hand, I often need to change separator elements as frequently as 2 tank refills (and I have used up to 400 gallons weekly this summer). At least I have kept that water out of the tanks of my tractors, CTL, and combine. I’ve also switched to using on-highway diesel despite paying road tax because I found I go a lot longer between replacing water separator elements. That also means I don’t need to make a special trip to fill my diesel pickup if I run low.

 

[tstex]

Great point M Harry...as you stated, adding anything will change the fuel system dynamics and that can wreak havoc fuel delivery.

Think I値l just stick to the basics of using good fuel, keep the tank filled and empty the fuel bowl much more regularly, esp when we have huge temperature swings. Houston had a temp of 85 & humid in December on yr, then a cold front popped thru and took us to 31 degrees. A day or so later it was in the high 60痴 lo 70痴...being so close to the coast the humidity can be 85-90% as well. Thanks for your feedback

 

[5030]

I'm with Jim. Keep the fuel tanks full at all times when sitting, add a good biocide like Power Kleen and in my case up here in the north country a cold weather diesel additive like Powerservice helps with fuel not gelling. I store my fuel in 500 Gallon bulk tank and that gets treated with biocide every time it gets filled and a gallon of Powerservice too.

6K hours on one tractor, 2500 on the other and the 6 went into the Kubota shop for a tune up and valve lash adjustment early last year and they pulled and checked the injectors and all was good. Had them put it on the dyno and it's making 91 pto. Supposed to be 81 so either it's running good or Kubota under rates their engine power.

 

[Tx Jim]

I also utilize power service fuel conditioner. IMHO a very important thing to do especially if water has been located in tractor fuel system is ""regular monitoring/inspecting water seperater bowl"" in lieu of operating tractor until presence of water causes engine to stop operating.