Bump up lift capacity of L3400/LA463 Loader

[LD1]

To add to what JJ said, The 3400 and 3700 uses a 1.77" cylinder. 100 psi is about 245lbs force per cylinder, or 490 for the pair.

Due to the roughly 5:1 Mechanical advantage of the loader acting on the cylinder, this is about 100lbs of actual lift force in the bucket.

Every PSI increase equals about 1 lb more that the loader can lift.

So if you are close to the 2300 mark, I'd leave it. If you are in the 1900-2000 range, see your dealer and explain this to him. As you are giving up roughly 300-400lb of lift capacity.

I have never actually measured how much mine will lift, but if a dealer refuses to fix low pressure, weigh out 1000 lbs of block/rocks/whatever and put them in the bucket and see if it can lift if. If not, the dealer almost HAS to fix because kubota lists 1014lbs of lift @ bucket center. If if can lift it and your pressure is low, that just means kubota under rates them big time.

 

[ritschner]

When I first checked mine the pressure was to spec, but sometimes the loader would struggle to break out with a bucket load of compost. Decided to shim the regulator 15 thousandths, so pulled the relief valve, inserted a shim, seated and torqued the valve, and checked the pressure. Wow, 3300 psi. It turns out the dealer put four shims in the relief valve and only turned in the valve enough to set the pressure at spec. When adding the shim, I bottomed the valve and instant, unexpected pressure boost. Ended up removing the added shim and two of the dealer shims to get 2650 psi. Thank goodness for gauges. At least I have to give the dealer credit for checking and setting pressure to spec when the tractor was new.

 

[Adiredneck]

Changed the hydraulic fluid in my tractor tonight. Could not think of a better time to check the hydraulic pressure. It was set at 2350#.

Bought an assortment of washers at the hardware store, but couldn't find the little bag they were in when I got home. I looked all over the garage, and the best thing I could come up with was a backup washer for some 3/16 rivets. Too much pressure, went to 3000#.

Finally went to the truck & found the washers (they ended up under the seat).

Put one stainless #10 washer in (quite a bit thinner than the washer for the rivet. I hit 2500# on the dot. I quickly drained the rest of the fluid, changed the filter & re-filled the tractor. It was getting dark at this point.

Hit my sand bank & got a huge bucket full of sand. No problem getting the bucket out of the pile. I'll do some more testing tomorrow night to confirm. I may end up with one more washer before I am done, hopefully this will give me another 150# increase. The SS washers seem to be quite uniform in thickness, so this should get me close to 2650#.

There was no shim at all in my relief, just the spring.

 

[hawkeye08]

I'm glad I came across this. I need to measure mine (L3130 w/LA723) and see. The tractor manual says 2560, loader says 2630, I am not happy with lift when cleaning ditch out... seemed to hit relief all the time. I will certainly measure with gauge first and at least see where I am at.

I need to repair a slow drip on one of the cylinders also... some good projects lined up.

Thanks to those that have shared on this one.

 

[LD1]

Changed the hydraulic fluid in my tractor tonight. Could not think of a better time to check the hydraulic pressure. It was set at 2350#.

Bought an assortment of washers at the hardware store, but couldn't find the little bag they were in when I got home. I looked all over the garage, and the best thing I could come up with was a backup washer for some 3/16 rivets. Too much pressure, went to 3000#.

Finally went to the truck & found the washers (they ended up under the seat).

Put one stainless #10 washer in (quite a bit thinner than the washer for the rivet. I hit 2500# on the dot. I quickly drained the rest of the fluid, changed the filter & re-filled the tractor. It was getting dark at this point.

Hit my sand bank & got a huge bucket full of sand. No problem getting the bucket out of the pile. I'll do some more testing tomorrow night to confirm. I may end up with one more washer before I am done, hopefully this will give me another 150# increase. The SS washers seem to be quite uniform in thickness, so this should get me close to 2650#.

There was no shim at all in my relief, just the spring.

If one more washer gets you to 2650, that sould be about 300lbs additional capacity at the bucket vs your 2350psi. Not to bad. But it It sure would have been nice if kubota had just made an adjustable valve. Like on most other hydraulic systems. Just loosen a jam nut, tighten a bit, an re-lock jam nut. Boy that would be nice

 

[dex3361]

If one more washer gets you to 2650, that sould be about 300lbs additional capacity at the bucket vs your 2350psi. Not to bad. But it It sure would have been nice if kubota had just made an adjustable valve. Like on most other hydraulic systems. Just loosen a jam nut, tighten a bit, an re-lock jam nut. Boy that would be nice

I bought the washers from Kubota for a few dollars and in the manual for the L4400.
The shims add aprox. 38.4PSI for each 0.1mm added.
It only takes 30 minutes start to finish to make the adjustment.
I would not exceed the upper pressure limit by much.
Here is a link to making the adjustment that I did foir a friend of mine who has a L4400HST just like mine only he has a Backhoe on his.
FEL PRESSURE CHECK and ADJUSTMENT

 

[Goog]

Since I started this thread I thought I should jump in here. It has been so long I went back and read the whole thread again.
No ill effects at all on my L3400. Last year I bought some really heavy round bales and had no problems at all. I lift pretty slowly and carefully because I know I am pushing the limits.
It is a completely different loader at the higher end of the pressure scale. I never did remove any shim and don't plan to. Brian

 

[VT6Kubota]

I am in the process of purchasing a new tractor, so far the L 3700SU is in the lead. Does anyone have any experience with a Woods Groundmover-X loader LC 102 ? the rated lift capacity is 1,200lbs; 500MM ahead of the pivot pins vs. 853lbs. on the LA 463, the hydraulic pressure on the wood is 2,500psi for the above capacity and uses 1.97 inch diameter cylinders.

Woods Equipment Company - LC102 Groundmover-X Curved Boom Loaders


the dealer will sell the woods for about the same price as the LA463. any comments?

 

[teg]

The Woods was "tested" at 2500 psi... the tractor will be set lower but cylinder diameter 1.97 vs. 1.77 will get you more lift... but I don't know exactly how much more.

 

[dpnhkubota]

Well I found out this morning my lift is just fine on a LA463 on a L2800. I was moving some large beams with the forks attached. I lifted them about 4 feet in the air, it did struggle. I was kind of disappointed at first until I started to back up. The rear tires came off the ground; I did not realize I had so much weight on it. Well that, and I was moving over some soft ground. This is with a bh57 attracted on the rear. Was a little scary, those front wheels don't keep you to stable. I was able to lower the load before the tractor rolled over. I have never done anything to modify the tractor has 200hrs on it. So I have only changed fluid once.