Weak Loader on my new L39! What is going on?

   / Weak Loader on my new L39! What is going on? #1  

mike69440

Elite Member
Joined
Jun 2, 2005
Messages
3,085
Location
Central NH (God's Country)
Tractor
1984 Kubota B7200D (Sold 2015,) 2005 L39 Kubota, 2006 RTV 900 1997 Komatsu PC75UU2E w/ Thumb & Blade, 2013 Mahindra Max28XL Shuttle
This weekend I used my new L39 TLB to remove a medium small size stump with the BH and used the TL 1000 FEL to grade the driveway and move some rocks and dirt.

My other tractor is a tiny 1983 B7200. I have about 500 Lbs of steel plate attached to the loader frame and the relief valve on the loader screwed in to give itch loader more capacity. The B7200 weighs about 2400 Lbs with loader ballasted tires and small weight box. It has a 4 Ft bucket.

I have operated a few other tractors like a 30 HP Kubota with as I remember a 723 Loader and an NH TC29 with Loader.

The L39 Loader performance seems very weak for the size of the bucket. I was very surprised and disappointed considering other peoples reports on the L39 and how Kubota touts the loader performance. The TL1000 Loader seemed very weak in its ability to curl, especially back curl. I am used to being able to move material and large rocks by backdraging. The L39 was maybe only at most 50% stronger overall than my little B7200 in back dragging, If I had more than 6 or 8" of dirt, the bucket would just roll forward when I back dragged. I found it difficult to drag a rock only marginally larger than what I would move with my little B7200.

The Loader will pick up the front end of the L39, but the Loader is stronger in the loader boom cylinders than the bucket cylinders. Does the boom cylinders have a separate relief valve from the bucket cylinders?

Other than being Limp wristed, the loader performance is normal from a control and speed standpoint.

The specs say the loader should be allot stronger than what I have experienced. The curl force on the bucket is supposed to be 5,000 Lbs. Mine seems like about maybe 2000 Lbs.

I also question the loader lift capacity. Although the TL1000 seems to be okay in this area, it is only about the same as the NH or the larger Kubota, I operated, which are Agricultural machines and not up to what I would expect from this highly touted TLB.

The bucket got stuck lifting a load of stone base from a soft pile.

If I used the backhoe and put the bucket front edge to bite the ground along with deploying the stabilizers, the loader would move around and not hold position when pulling with the BH.

I have read where others comment how strong the loader is. In one instance speaking of breaking chains with the loader and being able to lift the back of the L39 with BH attached off the ground with the FEL.

I can put the bucket edge under the edge of large rock and try lifting, neither the tractor or rock move. If I do the same with my weighted down B7200, one rear wheel will start to lift.

Before I bring this up with my dealer, I would appreciate others confirming that the loader performance I described is not right.

Thanks, Mike69440
 
   / Weak Loader on my new L39! What is going on? #2  
The L39 uses a regenerative dump circuit I believe. This is supposed to be for faster dumping. If you have a non-regenerative dump position ( it's hard right on the stick beyond the de'tent stop....push really hard...at least on my LA723 loader that's how it works), this will apply full pressure to the dump cylinder as you're expecting....ram extending.

The regenerative circuit simply applies the same pressure to both sides of the cylinder. Since the RAM side has less lateral surface area, the net force is outward...but not the full force that the bucket curl action provides. This allows them to pass the fluid more directly from the ram end back to the cylinder end....it speeds the dump time up apparently. Also if the bucket is loaded, the weight of the material in the bucket also helps the dump force.

In your case (if indeed you are only using the regenerative stick position of partial right) your backdrag maneuver may be overpowering the cylinder side force when it's in this regenerative mode. I would suggest trying the same thing with the hard-right non-regenerative stick position.

I personally would be happy to give up the speedy dump time if I could get rid of the regenerative goofy default control valve behavior, because I always forget the non-regenerative bucket dump position is there!
 
   / Weak Loader on my new L39! What is going on? #3  
That sure sounds odd to me. Our L-3130GST with the LA723 FEL does about as good a job as possible, but the L-39 is industrial grade compared to it.

Our TL1000 bucket boom strength is considerably greater than the LA723 by a long shot and the curl rollback is light years stronger, in fact it is totally awesome.

You might wish to check to make sure you do NOT have the auto-leveling function on, be sure to turn it off. Not sure how that affects boom and bucket cylinder strength but I know it slow down the raise and dump cycles quite a bit (I've only used it a couple of times).

Our TL1000 has carried and lifted as much a load as the weight of the entire machine can handle, dozens and dozens of huge boudlers and stumps without a whimper. In fact, I would NOT want any more FEL power as it is maxxed out in my mind by the weight of the entire L-39.

I've broken Grade 43 3/8" 5,250 pound rated chains loading a stump into the bucket and have also snapped a 3/8"welded clevis grap hook in 1/2 that I welded onto the bucket for attaching the chains to lift a boulder.

I would say something is wrong with yours for sure.

Perhaps you may need to change out the two hydraulic filters @ 50hrs. and see if there is any improvement in performance of the FEL & BH?????
 
   / Weak Loader on my new L39! What is going on? #4  
Here is a pic of the bucket, you can see the snapped off 3/8" clevis grab on the left hand side of the bucket.

It was welded on with my Millermatic 210 MIG welder and the steel clevis snapped in 1/2.

I don't think anything less than 5,000 pounds could do that......
 

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   / Weak Loader on my new L39! What is going on?
  • Thread Starter
#5  
</font><font color="blue" class="small">( Here is a pic of the bucket, you can see the snapped off 3/8" clevis grab on the left hand side of the bucket.

It was welded on with my Millermatic 210 MIG welder and the steel clevis snapped in 1/2.

I don't think anything less than 5,000 pounds could do that...... )</font>

Thanks for the Info SkyPup!

The way the loader is behaving, there is no way my L39 could handle the toothbar, it does not have enough ommph!

I hope that soon my loader could be strong enough to break a chain or hook.

Only way it could do it now is I got a **** of a running start in reverse!
 
   / Weak Loader on my new L39! What is going on? #6  
BTW, the weld on that 3/8" clevis grab held good, the weld is still there, it was the clevis itself that snapped in half! /forums/images/graemlins/blush.gif

Also, that is a custom super heavy duty 1 1/2" shank toothbar that weighs 140 pounds, the toothbar on my LA723 FEL on the L-3130 weighs less than 1/2 that.
 
   / Weak Loader on my new L39! What is going on?
  • Thread Starter
#7  
Here is some more info on my loader performance issues

I did the following to confirm the loader is not up to snuff.
I have a stripper V6 2 wheel drive 1998 F-150 1/2 ton Standard cab with 6.5' bed. 3900 Lbs empty, say at most 4,200 Lbs with the trailer hitch and some tools behind seat and a full tank of gas. Given the 60%/40% weight distribution that's 1700# tops on the rear wheels. Considering I can take most of the weight off the truck rear end with my little B7200 and that picking up from the trailer hitch gives more leverage than what sits on the rear wheels, I figure at most it takes 1,500 Lbs to lift the back end.
As a test I wrapped a nylon Lifting strap around the trailer hitch and tried lifting the back of my little F-150 from the hook on the top of the bucket. The L-39 really struggled to get the rear end 1" off the ground using the loader arm cylinders. I had to rev up the motor and it barely budged the truck. I know I did not lift from bucket center, but the loader still should have picked up the truck.

Given the Loader specs, even factoring in the front edge of the bucket vs. mid point of bucket rating the loader lift rating is shy maybe 15-25%. I would also expect that lifting from the edge of the bucket would make the machine a bit tipsy. The L-39 loader did not generate enough force to even lighten a rear wheel at all when I tried to lift.

The loader arm cylinders seem weaker than what I would expect, but it’s the lack of curl force from the bucket cylinders, that is really apparent.

I tried next using the bucket cylinders to curl and lift, but the L39 could not budge the F-150. It is the curling force that really weak! Considering Kubota publishes a curling force of +5,000 lbs, not being able to move the truck indicates that my initial impressions of a weak loader curl force is correct.

I used the Back Hoe to dig out two more stumps and pull out a few rocks. I am getting some experience with the BH. I like the mechanical thumb I purchased and the dealer welded on. The Back Hoe seems strong enough as the BH will move the machine around a bit before it stalls. This is the first hoe I have actually dug with, so unlike the other loaders I have used, I have nothing to compare it against.

The Loader will not lift the front of the machine off the ground with the stabilizers deployed on my L-39. Lifting the front end up with the bucket should be easier for my L39 as the 110 Lb mechanical thumb acts as a counter balance, and makes the front end of the machine lighter.

With the Stabilizers up, the loader will lift the front tires off the ground, provider the brakes are not set.

For those with L39’s, my questions are:

1.) What known loads have you lifted?
2.) If you place the bucket corner edge under something the loader cannot lift, and try to lift the object, will the back opposite unloaded tire lift?
3.) If you drive into a pile of fairly loose material, does the bucket get stuck or struggle to break out?
4.) Does the bucket curl capacity exceed the loader lift capability?
5.) With the stabilizers deployed, will the bucket lift the front tires off the ground?
 
   / Weak Loader on my new L39! What is going on? #8  
My L3830 with a LA 723 can quite easily pick up my F250 rear end. Long bed, extended cab. Your pressure must be low.
 
   / Weak Loader on my new L39! What is going on? #9  
can this be a simple thing that you are overlooking? On the L48 there are two levers that have to be re-adjusted in order to use 3pt vs hoe.. Does the 39 have something similar?
 
   / Weak Loader on my new L39! What is going on? #10  
The L-39 has a 3-pt circuit bypass to utilize either the 3pt or the BH (or the remotes). Possibly they are not totally engaged?? But then that would effect the BH performance, not the FEL.

All I can say is my TL1000 FEL rollback is to die for, it is awesome and an easy 5,000 lbs.....

Have you checked the hydraulic fluid level?
 
 
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