WEAK KUBOTA HYDRALIC'S

[COMPRESSOR]

QUESTION,
I BOUGHT A NEW B78OO WITH A JUST HAD TO HAVE B75 BACKHOE ATTACHMENT. THE PROBLEM IS THE LOADER DON'T HAVE AS MUCH LIFT AS MY OLD B8200,AND THE BACKHOE SO WEAK IT IS TO THE POINT THAT IF I HAD TO DIG IN ANYTHING OTHER THAT SOFT LOAM,I HAVE MY DOUBTS THAT IT WOULD DIG. THIS BACKHOE LOOKS AS IF IT COULD TEAR YOU A NEW ONE,BUT NO WAY.ANY 8 YEAR OLD KIDS TOY BACKHOE WOULD OUT PERFORM THIS ONE.I TOOK IT TO THE DEALER 70 MILES AWAY AND THEY SAID IT CHECK OUT. SO MY QUESTION IS THIS. THE HOE OPERATES ON THE TRACTOR HYDRALIC'S.THERE HAS TO BE A WAY TO SET THE RELIEF UP SOME HOW IN THE PUMP ???!!! OR AM I GOING TO HAVE TO INSTALL A PTO DRIVEN PUMP AND FAB IN A TANK SOMEHOW. SURLEY THERE HAS TO BE SOME KUBOTA WIZARD THAT CAN TELL ME SOMETHING THAT WON'T BE INSIDE THE MANUAL. THANKS IN ADVANCE TO ANYONE SMART ENOUTH TO ANSWER THE QUESTION.IF THE BACKHOE CAN'T BE SET UP ANY MORE,ANYONE WANT TO BUY A ALL BUT NEW B75 BACKHOE ATTACHMENT,BECAUSE I SURE DON'T WANT IT. THANKS DAVE

 

[cmhyland]

That sounds like something is wrong....

Is there another dealer around... 70 miles is a haul for sure...

Can you return the machine? Get you money back?

I have a B2910 and I'm very happy with it...

What is the loader rated for? Sounds like a faulty bypass valve somewhere...

Regards,
Chris

 

[hunterridgefarm]

Compressor,

Sorry I don't have the answer. But I do know many who have installed the PTO driven pump and are very happy with the performance. Difference in night and day.

Hopefully someone will have the answer you need.

 

[MadReferee]

The setting on the relief valve is probably too low. The fix is a simple adjustment that either you or the dealer could do in a few minutes. Since it's a new tractor it would be covered under warranty so I would let the dealer do it.

BTW, turn the caps lock key off. It makes it look like you are shouting and it is also hard to read.

tks

 

[RFB]

Compressor,

Check your system hydro pressure by using an inexpensive pressure gauge with a quick-connect fitting. Plug that into one of your loader QC's , and operate the joystick to activate the relief valve, and verify that your hydro pressure is up to spec. If it is not, you can add shims to the relief valve to restore the pressure to spec.

 

[john_bud]

As others have said, the relief is quite probably too low. There is a spring that holds the relief closed. Springs age and take a set, reducing the spring force. This is hastened with vibration and temperture.

You can either make your own shims or buy the correct shims from Kubota. They are usually 1/4" to 3/8" diameter washers. But thin!!!! 0.050" of thickness may be 100 psi or more, so don't just toss in a stack of washers and hope for the best. You could damage the pump and that is $$$. Personally, I would go to kubota and buy the correct shims and get enough for about 4-600 psi of increase. With steps of 50 or 100 psi. While at the dealer, ask them to print out the parts blow up of the relief valve and to tell you where it is.

It will probably be on the hyraulic block for the line going to the loader or in the loader valve.

Buy a guage from Napa or other high end auto parts store. They are surprisingly cheap. Get one that goes up to 3000 psi. The correct set point is probably around 2500.

jb

 

[BTDT]

I think some have reported about the quick disconnects not being hooked up properly. Restricted or no flow. Might post this on the Kubota forum as well, they can probably help.

 

[art]

With the range lever in neutral can you lift the front end of the tractor with the loader bucket? Will the backhoe boom lift the rear of the tractor? If this can't be done then it does need to be adjusted. The dealer although 70 miles away is the best bet and if you tell them that it won't lift the tractor they should know that it isn't right. You do have more hydraulics then a 8200 for sure but you didn't tell us what loader you had and there were some built and installed on those tractors that were after market and had more lift ability then the they should have for that size tractor.

 

[COMPRESSOR]

THANKS FOR ALL YOUR DIFFERENT INPUTS. I HAVE PUT A PRESSURE GAUGE ON THE BACKHOE. AROUND 1700 LBS IS WHAT I GET. I STILL DON'T KNOW WHERE THE PUMP IS LOCATED ON THE 7800 HYDRO. AND WOULD YOU BE ABLE TO SHIM IT.

 

[john_bud]

THANKS FOR ALL YOUR DIFFERENT INPUTS. I HAVE PUT A PRESSURE GAUGE ON THE BACKHOE. AROUND 1700 LBS IS WHAT I GET. I STILL DON'T KNOW WHERE THE PUMP IS LOCATED ON THE 7800 HYDRO. AND WOULD YOU BE ABLE TO SHIM IT.

It sounds like the main pressure relief for the hoe is too weak. Should be about 50-100 psi under the system relief. (guessing that the system is 2500 and the hoe is 2400 psi)

There was a site with all of the kubota parts manuals on it. Anybody able to post a link? If so, you would be able to find what you need there. If no link, call the dealer and talk to a service person.

jb