New Loader/Problems

[millwrightdude]

I have a new Bush Hog 2426 loader and for some reason it bleeds down. What can cause this?

 

[RoyJackson]

I have a new Bush Hog 2426 loader and for some reason it bleeds down. What can cause this?

They all bleed down...my 790 takes several hours (over night).

First question is, how fast does it bleed down?
Does it happen when the tractor is running?

A bit more information on what is happening would help considerably.

 

[millwrightdude]

It does not bleed down while running. It will bleed down a few inches is a short time.

 

[john_bud]

Hmmm - loaders when new (not just new to you) won't bleed down. My 2000 L3410 kubota will stay up for more than a MONTH.

If the loader is brand spanking new just put on, it may have air in the cylinders. Go full and hold for a count of 3, then full down and hold for a count of 3. Repeat than 5 times. All the air should be out at that point. (Same deal for the bucket curl cylinders)

If it is not air, then you have a leak. Fluid past the packing in a cylinder, fluid past the spool in the control valve or fluid out the cylinder onto the ground. A cylinder with the packing piston nut not tight will leak down.

If it is new and under warranty, talk to the dealer.

jb

 

[RoyJackson]

"Hmmm - loaders when new (not just new to you) won't bleed down. My 2000 L3410 kubota will stay up for more than a MONTH"

This had been discussed in the past, JB....Deere even supplied one of us TBNer's with the specs of allowable bleed down.
I'll see if I can still find the link to that thread.

Frankly, I'd of never noticed it until I read that thread...I never leave my loader up if the tractor is parked. For me, that's a safety issue. I just did an experiment one time after reading that thread.

 

[N80]

My Kubota LA703 will bleed down slowly when the tractor is not running. It has done so since it was brand new. I've never checked the rate, but it is pretty slow. 3pt hitch bleeds down fast if it has weight on it, but only when the tractor is off. This has also been the case since brand new.

 

[john_bud]

"HM - loaders when new (not just new to you) won't bleed down. My 2000 L3410 Kubota will stay up for more than a MONTH"

This had been discussed in the past, JB....Deere even supplied one of us TBNer's with the specs of allowable bleed down.
I'll see if I can still find the link to that thread.

Frankly, I'd of never noticed it until I read that thread...I never leave my loader up if the tractor is parked. For me, that's a safety issue. I just did an experiment one time after reading that thread.

Like you, I normally ground my FEL and 3pt for a belt and suspenders parking brake. But, This last winter curiosity got the better of me and I left the FEL up and the 900+ # box blade up. December to Jan -> both were still up. The box blade had dropped about 1/2 way down, but the FEL looked to be about the same height.

One thing to remember about MFG specs, they are written by the MFG, interpreted by the MFG for the benefit of the MFG. Think on this one. My truck (chev duramax) uses about 1/4 - 1/2 qt of oil in 10,000 miles. That is pretty normal behavior from talking to folks and reading forums. The GM "spec" for oil consumption is based on hours not miles, but as I recall it works out to about a full qt burned every 200 miles. Hard to not fall within that spec. If I was burning a qt every 200 miles and was told that it was OK and in spec - there would be something else burning as I got hot under the collar!

jb

 

[Farmerford]

millwrightdude:

I have the same experience as Roy Jackson and N80: the FEL's on a Kubota B2400 and a Kubota L4330 both leak down very slowly and have done so since new. On the other hand, my old 1981 Caterpillar will stay up for days.

The B2400 has a Husco monoblock valve and the L4330 has a valve with no name (I suspect Kubota just doesn't want me to know who made it so I can't get parts from a third party). It is certainly possible to seal virtually completely against hydraulic fluid, even at high pressure: consider the gland seals around the rod in a hydraulic cylinder. But those seals have significant "stickiness" that would make a hand operated valve more difficult to operate. And those seals would be more expensive to install because of the machining required deep in the bore. Given their relatively cheap cost, the valves on our FELs almost certainly rely on the fit of the spool lands in the bores to seal against leakage rather than packing or other "soft" seals.

And, because of manufacturing tolerances, most spools are "hand fitted" to the bores. That is, a valve body is matched up to spools that result in a fit within the manufacturer's specifications. I learned that when I tried to buy a replacement spool for a Prince directional control valve, and the manufacturer explained why they do not sell spools separately.

Say, just for example, that the manufacturer determines that a radial clearance of 2 to 10 microns is acceptable. If the raise/lower spool land to bore clearance in one valve is 2 microns and in another valve it is 10 microns, both will get shipped. But the first one will leak very little (perhaps none at all if the load is light) while the second one will leak much faster.

So, I think it is just the luck of the draw whether your loader has a tight valve that leaks little or none (under light load) or a loose valve that leaks down rather quickly.

I am not particularly safety conscious, but I do let all implements down when I leave the machine because neighborhood children often "drive" the machines when I am not around.

 

[RoyJackson]

Now, my 3PH with a 600# Ballast box has been setting there raised for 3 days now.
Figures...