Loader "float" freeze-up in winter

[Dr. Bob]

Could anyone advise me on this problem with my B7800/LA402?
When the temperature is below freezing, It is either difficult to get the loader control into the float position or if it goes in it will not lock in the float position (I have to hold it there). My suspicion is that there is a little water in that part of the system and it is freezing. In fact, if I take my wife's hair dryer (with her permission, of course!) and heat it up, it will work. But once it is shut down and sits in the freezing weather for a while, the problem reappears.
Any suggestions? The tractor is coming up on its 300 hr service that requires changing the hydraulic fluid. Is there anything special I should drain during that operattion?

 

[bigdad]

Check out the many threads on loader float freeze-up. It's an easy fix.

 

[johnk]

I think you have water in the valve. I had the same problem with mine when it was under warranty. They replaced it with one with a hole in it so the water drains.

 

[john_bud]

Agree, water is your enemy.

The side of the valve opposite the handles has a cap. It unscrews. You should do that and clean it out. There probably is a vent in the cap, but it also probably has been painted over and is no longer a vent!

Try to take the paint off the end of the cap with paint remover. The vent is usually expanded (foamed) metal like a sponge and is easy to clog up. If there never was a vent, you can drill a 1/32 hole. Just test fit it and mark where the bottom will be and drill there.

It's also possible that there is some water in the oil that is freezing. Next time you change hydro oil, extend the loader cylinders all the way out for both boom and bucket. Drain the oil, then float the boom down and muscle the bucket around so it will also retract. That will get more of the fluid out. Then fill with clean fluid. It's not unheard of for water to accumulate in loader cylinders. Mostly in tractors that are infrequently operated.

 

[7800DUDE]

I also had that problem when under warranty they also put a one with a hole in it an solved the problem.

 

[Killer_B]

I also had that problem when under warranty they also put a one with a hole in it an solved the problem.

Ditto my B7610, except it was out of warrantee. Easy fix, though.

KB

 

[Egon]

I have had that problem the odd time. Usually running the tractor and getting the oil warm in the hydraulics has nullified the problem!

 

[638]

If the oil is not milky looking, there is not any water in the oil.

ron

 

[N1ST]

Anyone know when abouts they made the drain hole part of the production tractor?

 

[rbargeron]

When the valve spool moves back to the float position it displaces a small amount of air in the back end of the valve. If the oil is too cold it's too viscous to let the air flow forward around the spool to relieve the pressure. The trapped air acts as a spring, pushing the valve forward from the float position. I use a bungee to hold the valve handle in the float position. Once the oil warms up a little, the valve will stay in the float position by itself. I think the "drain" hole is really there to vent the air out.

 

[Ob1kubota]

Dr. are you using SUDT or AW hydraulic oil?

 

[Dr. Bob]

Thanks to everyone for the suggestions.
John Bud: Thanks for the details. I will use your suggestion about the loader cylinders when I do the 300 hr hydraulic change.

I had heard from another Kubota owner about removing the "caps" and draining the oil out.

Can you drill a 1/32" hole in the caps using a hand drill?? Sounds like it would be hard to control and I don't have a drill press.

Ob1Kubota: I don't know which hydraulic oil I am using. It was the Kubota oil that the dealer sold me when I did the 50 hr maintainance.

683: I have not seen any milky apprearance on the dip stick for the hydro oil. So it is not a problem with water in the entire system.

When you are sitting on the tractor loking over the valve assembly, is it the left for right cap that needs to have the hole drilled in it?

Your guys are great!

 

[Ductape]

Dr., as was stated earlier...... your freezing has nothing to do with the hydraulic oil. Its all in the moisture that collects in the "caps" on the backside of your valve body. I had the same problem with my B2400. I removed the cap on mine...... only to hear a clink, clink. Looked at my floor to see springs and little steel balls (tiny ball bearing sized) under my tractor ! It took me putting it together and taking it apart about a dozen times to get my float to work again. This was the night of a large snowstorm...... i see you are smart enough to take care of the problem before you actually need to. I recommend you drill a small hole at the lowest point in your cap(s) with it on the tractor. Really no need to remove it as long as you can get at it with a drill. Under the cap is dry, provided you have no hydraulic leaks in there. Just be careful to stop drilling when you get through the cap.... though i don't see you hurting the spring in there by the drill touching it for a second or two. I also used the little hole i drilled to spray some lube up in there with the "straw" that comes on the can of lithium spray lube from time to time. Good luck !

 

[art]

The hole will help, another step is to fill the cap with a low temp grease.

 

[rbargeron]

The hole will help, another step is to fill the cap with a low temp grease.

But where will that grease go when the valve spool moves into the cap? Won't it tend to block the motion?

Here's a typical float spool - it's longer than a 3-position spool. Usually there's a spacer or a longer cap - it needs an air space at the end for the spool to enter.

This diagram is for a Cross BA valve - others I've seen are very similar.

 

[MarkLeininger]

I also had that problem when under warranty they also put a one with a hole in it an solved the problem.

Ditto on my 2710, bought it in November, couldn't use the loader in January. The dealer came to the house and replaced the valve.

 

[Dr. Bob]

Ducttape: Thanks for the warning on all of the little ball bearings and springs that are located under the cap! I was looking at the parts manual and noticed all of these little parts and was wondering just how smart it was to open this up.

Now my last question (I hope): Do you drill the hole in the very bottom of the cap, as in the end of it, or do you need to drill it in the side, but at the very lowest point? It would certainly be easiest to drill it in the bottom of the cap since it is flat rather than on the side where it is not so flat.

Thanks for the complement on thinking of solving this problem before before the next snowstorm. Thinking of it is easy; doing something about it is another story!

 

[john_bud]

The "best" is at the lowest point so it will drain completely. But an easy to reach place is probably 95% as good. When using a small bit in tight places, be sure to use a drill set and then high speeds and a very light touch. If you see it start to bend, it's broke --> so don't press hard.

 

[Ductape]

Dr. Bob, as John Bud said...... if you can, drill the hole at the lowest point on the cap. On mine, this was not in the center of the cap, as my loader valve sat at about a 30 degree (?? maybe) angle. Obviously the closer to the bottom you can make the hole...... the more water you will get out of there. Unfortunately for me, i had no exploded view of the valve body to use. It was challenging dabbing heavy grease on those little steel balls to get them to stay put while i tried to get that cap back in place. I'm confident i used a few expletives that night.

 

[Dr. Bob]

SUCCESS!!!
I drilled a hole in each of the detent caps (1/16", a little off center, towards the bottom).
Results, when viewed from the driver's seat: from the left one a little black oil ( about a drop came out); from the right one a few drops of water came out.
When I lowered the bucket (I had it fully raised to allow easy access), a few drops of the black oil came out of the left one and a "gyser" of water came out of the right one when I pushed it to float!

Seems that amount of water could easily have been freezing and causing the loss of the float function during sub-freezing weather.

A few learnings from this episode:
1. buy a good drill bit. The first ones I bought were from the local parts store and they didn't even complete the first hole. DeWalt bits went right through.
2. Looking on-line, it is suggested to drill metal at slow speeds. So, I put away my DeWalt electric drill (3000 rpm) and got out my battery powered, slow speed drill: much better results!

I don't know if it was the better bits or the slower speed, but the result was day and night.

Thanks to all who contributed advice. This site is great!

Now I can't wait for Winter so see if it solved my problem. Ooops! I really can wait. I hate Winter.