L 4740 hydraulics question

[Timan]

KennyV
Why do you say there is no practical way to install a bigger pump? Just Curious.

 

[J_J]

To check flow to a cyl on the BH, remove the hose from a cyl and place in a bucket. Run the engine at max rpm, and determine flow.

1.17 gal in 7 sec = 9.8 GPM

This may help you determine if you have restrictors in the BH hyd system.

9.8 GPM should be more than enough to operate the BH

As far as a larger pump, the volume your tractor is producing now takes about 25 HP.

If you could find an exact match and have the room,
you could add a larger pump.

You have enough total HP to pump about 24 GPM's at 2500 psi, with no HP left to do work.

What is the GPM rating on your BH?

 

[KennyV]

A J J said... and if you have unlimited $$ for trying to make a larger pump work in your tractor... Just seems impractical to me... a self contained PTO pump externally mounted would be quicker, handier & a lot cheaper .. KennyV

 

[J_J]

Another negative on the PTO pump other than price, is the pressure . 2250 psi, is lower than the tractor hydraulics.

However if you want fast hydraulics, use large GPM PTO pump, a two stage hyd pump, or a fast extend valve.

 

[Timan]

My backhoe needs 14 gpm at 2500 psi to be at peak performance.
Do you know if Kubota manufactures there own pumps? The control valves they use are Husco I believe.

 

[J_J]

I would think Kubota would offer a larger pump for BH option.