2004 Kubota L3130 HST Bogging Down

Piper2022 · Jun 3, 2023

Howdy,

We have a 2004 Kubota L3130 HST with 1300hrs on it. Been a reliable machine until the last few hours. We have noticed the engine bogging down more and more. The engine bogs similar to when you push too hard on the pedal when its cold or when in too high of gear range, except when its doing this it can bog in low range on even a small hill. It is hit or miss tho, like when moving dirt with the loader some movements its bogs worse than others. Another weird thing is when its bogging on say flat ground if mid engine bog with the pedal forward I go from forward to reverse the tractor will then not bog in reverse. Reverse clearly does not bog as easily and nearly not at all.

Some info and ideas:

1. Some might ask if I know exactly how to operate a HST, I have many hours on HST equipment so this is not an issue.
2. Fuel filter looks clean and engine runs well other than the bogging. For example the loader and backhoe have plenty of power.
3. Both the hydraulic and transmission filters are roughly 100 hours old, however the backhoe has some heavily weeping pistons so maybe backhoe use has something clogged.
4. When we blew a hose one night the only tractor fluid we could get was the Navi Guard Universal Tractor Fluid NAV TRACTOR HYD FLUID 5 GALLON PAIL Napa said it meets the Kubota specs a long with many others so hopefully this is not the issue. We added about 2.5 gallons of this 20 hrs ago with the bogging issue starting just about 2 hours ago.

Updated: When the issue first started and before I tried it in reverse I thought the parking brake was stuck on, but tires spin by hand when I jacked it up with the outriggers.

Any thoughts on where to begin? I am a decent backyard mechanic, but not with trouble shooting issues like this.

Thanks!

seville009 · Jun 4, 2023

You say that you added 2.5 gallons of hydraulic fluid 20 hours ago - have you checked the fluid level since the bogging down started in case you’re losing fluid somehow? You probably have, but figured it would be best to ask.

Piper2022 · Jun 4, 2023

Yup! Checked it and topped it off as one of the first things when it started acting up.

Well its funny that you ask this… a little development this morning. When staring at the fill cap of the tractor fluid after checking the fluid level when it was cold something didn't look right. A mid wasp or similar had tried to build a nest in the tiny vent tube(maybe 3/8” ID at most). I cleaned this out fully with a compressor away from the tractor, but maybe a bunch of dirt and debris has been working its self into the tranny? Hopefully the filter would catch it before any harm is caused.

New filters first thing tomorrow morning if my dealer has them in stock, anything else?

Smokeydog · Jun 4, 2023

New super Kubota super UDT with new filters? Very few oils meet Kubota specs and HST is very picky.

NUTTERDW · Jun 4, 2023

Piper2022 said:
Howdy,

We have a 2004 Kubota L3130 HST with 1300hrs on it. Been a reliable machine until the last few hours. We have noticed the engine bogging down more and more. The engine bogs similar to when you push too hard on the pedal when its cold or when in too high of gear range, except when its doing this it can bog in low range on even a small hill. It is hit or miss tho, like when moving dirt with the loader some movements its bogs worse than others. Another weird thing is when its bogging on say flat ground if mid engine bog with the pedal forward I go from forward to reverse the tractor will then not bog in reverse. Reverse clearly does not bog as easily and nearly not at all.

Some info and ideas:

1. Some might ask if I know exactly how to operate a HST, I have many hours on HST equipment so this is not an issue.
2. Fuel filter looks clean and engine runs well other than the bogging. For example the loader and backhoe have plenty of power.
3. Both the hydraulic and transmission filters are roughly 100 hours old, however the backhoe has some heavily weeping pistons so maybe backhoe use has something clogged.
4. When we blew a hose one night the only tractor fluid we could get was the Navi Guard Universal Tractor Fluid NAV TRACTOR HYD FLUID 5 GALLON PAIL Napa said it meets the Kubota specs a long with many others so hopefully this is not the issue. We added about 2.5 gallons of this 20 hrs ago with the bogging issue starting just about 2 hours ago.

Updated: When the issue first started and before I tried it in reverse I thought the parking brake was stuck on, but tires spin by hand when I jacked it up with the outriggers.

Any thoughts on where to begin? I am a decent backyard mechanic, but not with trouble shooting issues like this.

Thanks!

I have a B1550 that I bought used and after it ran for around 30 minutes it would start bogging down. I did all of the usual things, Filters good fuel and all. did not help. Took it to the Kubota dealer and he found that the part of the hydrostatic drive fluid was getting bypassed. In my case it was a 4000 dollar repair job so I moved it to my farm where we don't mow very much and purchased a new on for my home. We have also found that if we run the old one in high range it will run longer before bogging down.

Piper2022 · Jun 4, 2023

Smokeydog said:
New super Kubota super UDT with new filters? Very few oils meet Kubota specs and HST is very picky.

Hopefully its easy as that! The Navi Guard oil I have mixed in says meets UDT right on the bucket so it should work? Or work well enough for it to run decent?

Smokeydog · Jun 5, 2023

Piper2022 said:
Hopefully its easy as that! The Navi Guard oil I have mixed in says meets UDT right on the bucket so it should work? Or work well enough for it to run decent?

Not an oil expert but learned decades ago the right oil and filters matters in the long run.

Was experiencing loss of power and black smoke once. Mice had packed my air cleaner housing full of small acorns. Didn’t hurt the filters. Screened the inlets on both tractors after that.