Weak FEL hydraulics on Kubota L3240 with LA724

   / Weak FEL hydraulics on Kubota L3240 with LA724 #1  

Kurtkj1

New member
Joined
Sep 27, 2009
Messages
5
Location
Decatur, Al
Tractor
Kubota L3240
I have a Kubota L3240 with the heavy duty LA724 loader. Only got 102 hrs on the machine and I have issues with the FEL. I have tried to get Kubota to correct the problem with no success because the tractor is 2-1/4 yrs old and they said out of warranty for the hydraulics, no matter how low the hours.

1) I first noticed the problem when I got the front tires stuck couple of weeks ago and could not get any help from the FEL by curling the bucket to push be back. When I got the tractor pulled free, I tested the FEL strength on flat ground with no obstructions to see if the loader would roll the tractor by curling the bucket, it WOULD NOT curl when I lifted the front end off the ground. This test was on flat ground, in neutral, no brakes, front tires lifted off the ground, did test at idle and 2500rpm. :confused:Is this a fair test of the FEL strength?:confused:

2) I was doing some back scraping with the FEL bucket curled all the way in dump position to remove some sod. The bucket will not hold firm, it bounces and makes divots on the ground surface. The bucket probably flexes 4-5 inches while backing up and scraping the ground. I had the bucket in full dump position and not in the override stop location on the control lever.

I think I have a FEL problem, but not enough experience to know for sure. If this is how the tractor performs, then I will be selling and get another. I have read some posts about gauges to check pressure and using shims in the relief valve to make corrections. Help on checking and correcting the issue will be greatly appreciated. Don't want to damage my tractor by not having the full picture.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #2  
Welcome to TBN:D

1) First, you must get a gauge and test the pressure. A lot of Kubota's come from the factory with the PRV (pressure relief valve) set below spec. A gauge setup will cost you under $40 and is necessary to further diagnose your problem.

2) The "floppy bucket syndrome" is also fairly common. There is a very good explanation in THIS recent thread, as well as THIS one from Kubmech explaining the "regen" feature of the loader valve.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724
  • Thread Starter
#3  
Thanks for the welcome. This forum will be a great place to gain information about my tractor.

1) I purchased a gauge setup yesterday evening and had time to measure one of the four connections for the FEL. I used a Tee for the gauge and plumbed the inlet and outlet of the QD running thru the Tee. From my documentation of the loader QD locations, I put the gauge on one of the curl supplies which is on the second segment. It read 2580 PSI. I called the local dealership about what the pressure should read and they said the range is 2480 to 2640 PSI. Hope they understood what I was asking. Do I need to check the other curling location? Do I need to check the boom lift 2 fittings for pressure? I read that the QD fitting could cause issues with loader performance and to connect several times to assure they are functioning properly. I did this and cycled the boom and bucket to remove air. Still does not curl with the tractor lifted.

2) I read the links you referenced. Great information on how the regen feature works. My manual says I have a Double-acting 2-segment hydraulic control valve for the front loader. It says the first dump position features greater speed for dumping. The second dump position (further to right) is the "Regular" dump position, good power and control for precision. This seems a little confusing to me as for precision since the lever has little movement at that location. I only use the first dump postion due to the control you have over the bucket location. I have not tried to back scrape after curling the bucket by using the second dump position. The Kubmech article said, "Thus, if you have the 4-pos. valve and want to avoid the floppy bucket syndrome you have to push full right to engage regen". I will have to try this today. Seems Kubota would have mentioned this in the manual.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #4  
1) There is only one relief valve for the loader valve, so you only need to check one of the QD's. You can also just plug the gauge into the QD-there is no need for the Tee because you are deadheading the pump anyway.

Your pressure sounds inline with most other CUT's...There could be internal leakage in the cylinders causing your problem but then you would have very fast leakdown also.

2) I believe on the newer Kub's, the "regen" is on the first part on the joystick flow-opposite on what Kubmech said. But either way...holding the curl against the stops and sending the valve into relief for a few soconds should help eliminate the floppy bucket.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #5  
On a Prince valve with regen, the regen is engaged when the lever is held to the outermost position. If you want full force, pull the lever back a little. There is a so called "feel" position.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #6  
Kurtkj1 I would be cautious when back dragging in the way you're describing it puts a great deal of strain on your cylinders. Most of the recommendations are to use the heal or bottom of the bucket. I will often angle the bucket down a bit in the dump direction and back drag but keep in mind dumping all the way down will increase the stress on the cylinders. It is even worse to go forward in this position and try to bulldoze in the dump position. Thoughts on this from any others. Something to consider anyway.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724
  • Thread Starter
#7  
Thanks for the thought on back scraping. It will be interesting to see if anyone comments about this technique. My brother-in-law has a Kubota 3130 and he uses this method for final leveling, or removing the grass. I kinda picked this up from seeing him use it with the Kubota and Case backhoe. If this is a bad thing, then I will have to rethink my methods. I have used this method a lot in the past with the 3130 and was trying to do the same with my 3240 when this flex in the bucket showed up.

I have never gone forward with the bucket in full dump position.

Do you think that the "floppy bucket" syndrome when back scraping is a natural thing due to the stress put on the 2 bucket cylinders? Or should they have held firm, but I could cause damage in the future with this method?

Thanks
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #8  
Back dragging with the bucket dumped is the best quickest way I know of to bend your bucket cylinders......It probably says so in the loader manual, it does in mine....Good luck.
 
   / Weak FEL hydraulics on Kubota L3240 with LA724 #9  
Kurt,

The Case backhoe loader bucket cylinders collapse as you dump the bucket - the Kubota cylinders extend. If you hit something at a full gallop with the cylinders extended, somethings gonna give and in my sad experience it is the often the rod of the dump cylinders. You can bend them.

The other technique of using the bucket flat will give almost the same result as far as grading job when back dragging and will protect your cylinders.

Good luck!
 
 
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