Fuel water separator after market

coketractor

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kubota m5400
Apr 9, 2024
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I have M5400 Kubota 2wd tractor with 1200 hours. Made in 1990's obviously no DEF. It has the common canister particulate fuel filter (see picture), but no fuel water separator. I just got into some fuel with water because my Bobcat skid steer was throwing water in fuel code and i was having to stop and drain fuel water separator frequently. Same fuel also put in my kubota, but it is running fine.
I went by Kubota dealer yesterday, and they confirmed this unit was made without fuel water separator. The MX5400 (4wd) does have a separator, but not my M5400.
Wondering if anyone has added after market separator?
Since it has 20+ years of running flawlessly, a mechanic friend of mine advised me don't try to fix what isn't broke. He thinks that engine is so old school bare bones that it will handle a small amount of water and just burn right thru it. I just ran it on nearly continuous 14 hours doing spring planting and it never missed a beat with same fuel that was throwing water code with skid steer (there was water i could see when i drained the separator on skid steer- not just a false sensor).
I also have 1980's Iseki tractor and 1999 Ford pickup diesel neither of them have separator and neither have issue. Wondering if the old diesel engines more resistant to water issue whereas newer computer controlled machines are much more sensitive. I don't know if that even makes sense given all diesels still run basically the same.
 

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JasonW

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Jan 29, 2015
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Al
That filter setup looks similar to the one on my MX5100.
If you have water in the fuel it will hold in the bottom of the filter housing. I’d suggest getting a new filter and new(clear) filter cup and O-rings.

The new models have a separate water separator/pre filter in addition to a spin on fuel filter.
 
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Runs With Scissors

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Since it has 20+ years of running flawlessly, a mechanic friend of mine advised me don't try to fix what isn't broke.
He sounds like a wise man.

Drain that canister if you see water, and be done with it.
 
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GeoHorn

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Your M5400 and my M4700 are essentially the same …they share the same Operators Manual…the major difference is the same engine is operated at a (100) higher RPM to achieve another few HP (7) and torque (12 ft-lbs).

The Ops Manual has instruct’s for 100 hr fuel filter cleaning and 400 hr replacement. It refers to a completely separate section dedicated to fuel system “bleeding” when the filter is cleaned or changed…. that complicated procedure is: [ Open fuel cock. Run engine 30 seconds. Stop engine.]
😳

The existing fuel filter bowl is designed to allow water to separate-out. Since you’re cleaning the bowl every 100 hrs…you can inspect for water and dump it out.

The problem for water in the fuel is that it will turn to steam at the injectors and quickly erode/damage them. Preventative action is a good one…and your interest in adding an aftermarket water-separator is well-intentioned…but likely unnecessary. You can prevent water from entering your M5400 fuel system when you refuel it…by running the fuel through a water-separator funnel.

PM me if you want a copy of the M4700/M5400 Ops Manual.
 

PoTreeBoy

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Since water in diesel grows algae, you might want to think about adding a biocide for prevention. Be careful with it, that stuff's toxic.
 

fried1765

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
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I have M5400 Kubota 2wd tractor with 1200 hours. Made in 1990's obviously no DEF. It has the common canister particulate fuel filter (see picture), but no fuel water separator. I just got into some fuel with water because my Bobcat skid steer was throwing water in fuel code and i was having to stop and drain fuel water separator frequently. Same fuel also put in my kubota, but it is running fine.
I went by Kubota dealer yesterday, and they confirmed this unit was made without fuel water separator. The MX5400 (4wd) does have a separator, but not my M5400.
Wondering if anyone has added after market separator?
Since it has 20+ years of running flawlessly, a mechanic friend of mine advised me don't try to fix what isn't broke. He thinks that engine is so old school bare bones that it will handle a small amount of water and just burn right thru it. I just ran it on nearly continuous 14 hours doing spring planting and it never missed a beat with same fuel that was throwing water code with skid steer (there was water i could see when i drained the separator on skid steer- not just a false sensor).
I also have 1980's Iseki tractor and 1999 Ford pickup diesel neither of them have separator and neither have issue. Wondering if the old diesel engines more resistant to water issue whereas newer computer controlled machines are much more sensitive. I don't know if that even makes sense given all diesels still run basically the same.
Buy "Mr. Funnel" !!!!
Will work for any/multiple machines.
No hard install required.
It will not pass water!
 
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coketractor

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kubota m5400
Apr 9, 2024
3
0
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Texas
I added a goldenrod fuel particulate/water filter to my portable auxiliary tank instead of just a particulate filter. Will try to run my diesel thru the filter prior to going in machines since we have gotten water in diesel straight from the station.
I did more reading on new vs old diesel engines. It does seem the engines have changed....specifically my 2018 bobcat skid steer has the fuel rail with high pressure atomization of fuel "to make it more efficient." From what i read, this rail-high pressure system makes it super sensitive to water. In fact, the machine idles down and will not go back to working rpm until you get out and drain the fuel water separator. I now make it a habit to drain fuel water seperator prior to cranking skid steer.
It's funny to me i have never really worried about small amount of water on my 80' and 90's diesel engines. I do think i need to be more diligent, but it also seems like the "improvements" in new diesel engines have created a new set of problems.
I also ordered some fuel treatment from Bell. Supposedly the diesel additive forms micelles with tiny water droplets and helps it burn thru the machine.
The bobcat fuel water separator seems to be so efficient that probably i should just let it do it's job. I'm not really sure much water gets separated in kubota fuel filter. I guess it can settle out in bottom of fuel filter bowl, but I do so much bouncing around when i am working the tractor, it is hard to believe the water doesn't get aggitated and suspended in fuel and go right thru the engine.
 

JasonW

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Jan 29, 2015
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Al
I’ll add this. There are two types is diesel fuel treatment. Emulsifiers and demulsifiers.

Emulsifiers help to distribute water throughout the fuel, it breaks the water down so it passes through the system.

Demulsifiers assist in the separation of water from fuel and can break existing emulsions. Which would be seen as water buildup in the fuel filter/separator.

Older mechanical injection systems can handle some water going through them. I don’t want to introduce any water into a high pressure common rail engine. I would rather catch it in the water separator.
 
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Russell King

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Search “racor” on this website for many threads about filters and water separators
 

fried1765

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
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Search “racor” on this website for many threads about filters and water separators
Racor filters/ water separators are great!
I had two large ones on my boat.
I had 900 gal. diesel capacity aboard.
The simple (cheap) solution, for a homeowner diesel tractor is a Mr. Funnel.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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Austin, Texas
Racor filters/ water separators are great!
I had two large ones on my boat.
I had 900 gal. diesel capacity aboard.
The simple (cheap) solution, for a homeowner diesel tractor is a Mr. Funnel.
The problems I have with the Mr. Funnel is that the flow rate through the funnel is limited unless you get the higher flow rate version and the amount of foam that piles up in the funnel
 

fried1765

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Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
Nov 14, 2019
6,657
4,207
113
Eastham, Ma
The problems I have with the Mr. Funnel is that the flow rate through the funnel is limited unless you get the higher flow rate version and the amount of foam that piles up in the funnel
I am an old guy,......so very accustomed to low flow rate. :giggle:
 
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