Lowering loader arms puts strain on engine

[dannyk]

A couple of us with L-39s have noticed that the engine seems to labor when the loader lift arms are lowered. There is no such effect when raising the arms or curling the bucket. This seems counterintuitive, since gravity should be helping the lowering movement. When engine rpms are increased, I notice a distinct hydraulic whine when lowering the loader arms. At low rpms the engine stumbles noticeably.

Question: Do we have defective loader valves or hydraulics, or is this just something that some Kubota loaders do?

My machine has done this since the day it was delivered.

Comments by anyone having similar experiences or knowledge of loader hydraulics would be much appreciated!

Danny

 

[SPYDERLK]

There may be an intentional valve restriction in down direction to prevent quick descent when heavily loaded?
larry

 

[otus_branch]

Hi Danny,

Haveyou tried turning-off the self-leveling function, and comparing the noise then? I have noticed that L-39's seem to work rather hard to keep their buckets level...

-otus

ps- I think this is normal, but am open to hearing arguments on the matter.

 

[dannyk]

Otus,

The situation I am describing is with the self-leveling function off.

When I sent Kubota a message about this, they replied as follows:

"Thank you for your email regarding the issues on your Kubota L-39. Solving
these types of problems requires a complete workshop manual, the proper
test equipment and thorough diagnostic procedures. The information you
provided in your email is not sufficient to supply an accurate response.
Consequently, we recommend you contact your local Kubota dealer and make
arrangements with their technicians to resolve your concern.

Thank you for purchasing Kubota products."

Danny

 

[john_bud]

A couple of us with L-39s have noticed that the engine seems to labor when the loader lift arms are lowered. There is no such effect when raising the arms or curling the bucket. This seems counterintuitive, since gravity should be helping the lowering movement. When engine rpms are increased, I notice a distinct hydraulic whine when lowering the loader arms. At low rpms the engine stumbles noticeably.

Question: Do we have defective loader valves or hydraulics, or is this just something that some Kubota loaders do?

My machine has done this since the day it was delivered.

Comments by anyone having similar experiences or knowledge of loader hydraulics would be much appreciated!

Danny

Not sure, but could it have to do with the regeneration feature of the loader control valve?

jb

 

[dannyk]

Well, yesterday I hooked up the grapple and worked the front hydraulics. After doing this, the situation seemed better. There's still a fair amount of hydraulic noise, but this may be normal. At least the engine did not seem overtaxed. I will post again on this thread if I have more instances of engine lugging.

Danny

 

[Muleskinner]

My L39 does the same thing. I believe it's because the L39 has 23GPM hydraulic flow. That's a BIG pump for a three cylinder 39HP engine to handle. But why it does it on the down stroke is beond me.

 

[JamesT]

Yes, my L39 drags on the engine when using the FEL, but seems not to do it when loaded.