Bump up lift capacity of L3400/LA463 Loader

[Flgaline]

I read thru this thread and decided to check the pressure on my system. (Kubota 3400 HST with LA 463 loader) Found it was set at just under 2200 psi. pulled the plug (22MM) and found zero shim in place. I added a #10 SS flat washer that measured .028 thick. Next check on the pressure was at 2600 psi. I think I will leave it right there based on the earlier posts that I read. Thanks for all the good info I have been able to garnish from all of you

 

[Tomtint]

Well, about a year or more ago when I first read this thread. I went to my local Bota dealer and bought 5 shims. They are paper thin and have been sitting in my tool box ever since. So today I decided to get a gague and get er done. From the factory it came in at 2200 lbs, it had no shims in place. I first installed 2 of the Bota shims and I was up to 2450, then another 2 and I was 2700. I'm going to leave it there and see if I can notice any improvement. All in all, it took me about 15 minutes to do. I just let the fluid drip into a clean bucket each time I pulled the valve. Combined fluid loss for the 2 removals was about a quart max.

 

[Tomtint]

My update, as I posted yesterday I installed 4 Kubota shims in the valve. I have a set of Cat Skidsteer forks that probably weigh 300 pounds, and it has always been a struggle to load or unload my 8' sander from the back of my truck. The Bota just did not have the sack to do it. Well, I just went out and gave it a shot and it now has absolutely no problem what so ever. The 4 shims bumped the pressure about 500lbs and clearly that worked. This will likely be the heaviest thing the tractor ever lifts and it may only be a couple times a year. So all in all, I think it was .75 cents well spent.

 

[bumperm]

Bought a gauge and quick connects some time back, just haven't gotten to it. After dinner I hooked the gauge up to the FEL on my B3350. The shop manual says it should be 2400 to 2450 psi. Mine measured 2050 psi. 20% lower than minimum spec is pretty dismal and is probably the reason my BH77 is so easy to max out. I will check the power beyond pressure going to the hoe to make sure the relief valves in the hoe are set reasonably when I get a chance.

Going in, there were 3 shims totaling 2.31 mm I ended up adding 1.90 mm to get to 2500 psi. Checked the stabilizers and boom and dipper on the hoe and they all bypass at 2,500 psi. This should make a major improvement in the backhoe for sure. I'll be using it tomorrow to replace a 4" drain line, but that won't be much of a test. Some aspen tree stumps will provide that later. Woohooo!

 

[spock]

Is this adjustment in the same location on the Grand L3430?

Thanks

Spock

 

[spock]

LA723 loader BTW.....

 

[teg]

I don't know your model but would guess it's about the same... but it's ONLY a guess. Can you post photos of the area?

From a manual found online, it looks to be about the same (pg. 424):
http://www.kubota.cz/data/manualy/l-30-wsm-en.pdf

 

[bumperm]

If you hook a shop vac up to your hydraulic fill port, you can remove relief valves, fittings etc. (or change filters etc) without significant loss of fluid.

 

[newbury]

Kubota loader valves typically don't have relief valves in them. They rely on the system relief ONLY. The BH's may be powered from a PTO pump, so the controls DO contain a relief.

If you have a BH and want to bump pressures, you DO have to coordinate the change with both system and BH relief.

Explain "coordinate"? Do you mean just keep it under the BH's PRV?

After reading this thread, admittedly fast, and others on this subject to the point my eyes are about to lose focus, let me see if I have this right.<snip>

It's only a little over 300 posts!

Checking pressure at the loader work ports does not check the 3pt.

You only have one relief valve and it uses shims. It is on the bottom of the loader valve. It is the relief valve for the tractor hyd system.

If you want to test the 3pt you need to find another gauge insertion point. Loader plug in will not work.
<snip>

But if I set the PRV for 1900 won't that be the max throughout the system?

Well, I've read through 29 pages of this thread! Wowza talk about keeping it alive!!!<snip> I have a shop vac, but I never did see a pic on how to hook that up???
<snip>
2. How do you hook up the shop vac?
<snip>

It's in the thread. I just reread the entire thread and saw the pic with the vacuum hose in the fill port.

If you hook a shop vac up to your hydraulic fill port, you can remove relief valves, fittings etc. (or change filters etc) without significant loss of fluid.

Warning - one poster in this thread reported his vacuum sucked in fluid.

I finally tested my B7610 and it read 1700 off a loader port. Spec is above 1900 (1960?, it's in my WSM). Spec for my Woods BX70 BH is above 2000.
Main points I remember from the last 300+ posts for the procedure:
Keep it clean
Test and record, if below spec go for it, expect to need 0.1mm of shim for each 38PSI bump on the bigger tractors
Have shims on hand
Put a vacuum on the fill port
Maybe plug the vent hole
Have a plastic plug for the actual drain hole
Have a clean pan for fluid if the above 3 fail
The spring is not likely to spring out and go shooting across the shop (one of my concerns)
Record what IS there
Shim a little
close it up and torque to spec
Remove vacuum and plug
Test again
Repeat if necessary

So in my case where I'd like to add about 250lbs of pressure I'll plan on needing 0.6 or 0.7 mm of shim.
I should probably put in 0.3 to start.
Does that sound right?

Any other tips? Any youtube videos of the procedure on a B7610?

One of the scary things is when everyone says "it's easy", but their equipment is different (L3400 vs B7610) and something goes wrong.

 

[bumperm]

Warning - one poster in this thread reported his vacuum sucked in fluid.

.

I suppose to have that happen one would need to insert the Shop-Vac nozzle into the fill port to a point where the nozzle is too close to or into the oil. This is probably bad form and not recommended. So check the length of your hose and the level of your oil before starting :c).

Not sure of any reason to plug the hydraulic oil vent, at least so long as there's no dirt around it that might be sucked in when the vac is on. A good shop vac won't even know the vent is there, in fact it's easier on the vac to have some air leakage so as not to overheat the motor. When you completely block the vac nozzle you can hear the speed increase as the vac's impeller blades cavitate and lose efficiency, the motor also loses cooling air, so it's advisable to either limit the time the vac needs to be on, or provide some degree of air leakage (it'll still maintain enough vacuum in the hydraulic reservoir to prevent leakage).