LA853 Frozen Control Valve

[4630 GSTC]

I have had an ongoing problem with my FEL bucket curl once the temps get below freezing. It goes away once the tractor has run for 1/2 hour or so. I finally traced the problem to water in my control valve. There are two rubber caps on top of the control valve. The inner cap (on the left if looking from the seat of the tractor) has a tear on the top which has allowed water to get into a breather hole (unsure of the function). I left the tractor outside last night and to replicate the problem and sure enough, when I removed the rubber cap there was ice coming out the breather hole and the bucket curl would not work.
My question: Has anyone taken this apart to dry, clean, or lubricate? If so, is there anything to beware of in the way of springs, bearings, bushings or the like. Does anyone know of a diagram available depicting this? Mine is a cab tractor if that makes a difference. I have my garage all heated and would like to tackle this problem this evening before I go play on my neighbors frozen driveway.

 

[B2400]

Allow it to warm up,melt and then maybe a liberal dose of WD40 as it is a water dispersant?!

 

[john_bud]

There probably is a bunch of springs and maybe detent balls.

There is a web location where the parts break down for that loader lives. Someone here should be able to direct you.

Attached is a exploded view of the 723 valve. Yours will be similar.

 

[4630 GSTC]

Thanks for the diagram, very helpful. On my 853 the caps are on the top, as opposed to the diagram you sent. This, coupled with a leaking rubber cover allowed the water to leak in from the top and work its way into the assembly through the air hole on the end cap. My question to all is this, if I unscrew letter F or P what happens to A-Z?http://www.tractorbynet.com/forums/images/smilies/smile.gif
Last night when I used the loader I left the rubber caps off to see what would happen after it thawed and I used the bucket curl. Sure enough, probably 1/2 teaspoon of water spewed out that air hole as I began to curl the bucket. Thanks for the info.

 

[Ductape]

I've only had experience with vavles with the caps lower than the valve body. The cure is to drill a small hole at the lowest point on the end cap, to allow the moisture to drain. I suspect on yours that would be about where the top of the threads would be. On mine, when i removed the cap, i had balls and springs all over my floor and it took a couple hours to figure out how they all went back together. It would have saved me alot of aggrivation to drill the hole while the cap was still on the valve bady. I suspect with your valve "upside down"....... you are not going to want to drill the hole without removing the end cap first. You are certainly on the right track figuring your problem is the moisture that has gotten into that end cap........ unfortunately i can't tell you what will pop out if you remove that cap.

 

[4630 GSTC]

Unfortunately my caps are already drilled. This, coupled with the tear in the rubber boot caused water to leak in rather than allow air to leak out. There must be someone out there who has taken this unit apart or has knowledge of the hazards in doing so. I talked with a mechanic from the dealership where I purchased the tractor. He did not seem to be familiar with unit and advised that if the joystick were in the neutral position that it would not be under any pressure? or cause any flying parts. Thanks for your input Ductape. I fear that your experience with removal of the end cap is exactly what I can expect.

 

[art]

We also add grease to the caps to lower the amount of air room for condensation.

 

[4630 GSTC]

Art, have you had one of these units apart? I assume that you must have taken it apart to add the grease? What type of grease would you recommend? I would think that the grease may take awhile to warm up if it is below zero? I still haven't heard enough reassurance to dive in and take this ticking bomb apart. Anyone else have any ideas regarding this? Thanks.

 

[Ductape]

Are you near your Kubota dealer? I'd stop in and ask parts or service to print you out an exploded view of your valve. When i had mine apart on my B2400, it was frustrating, but not terribly difficult to get it back together. Certainly not worth taking to the dealer and getting charged shop labor. If i'd had access to an exploded view, i would have had mine apart, cleaned up, drilled, lubed and back together in a half hour. How i didn't lose the metal balls (the size of BBs) in the wooden floor of my barn i'll never know. Mine, i just used white lithium spray grease, injecting it through the small hole i drilled with the included little red straw thingy. Once i got the water out of the cap, i never had another problem. You won't want to hear this........ but with mine, once it was below freezing, my valve would NEVER thaw out and work properly, no matter how long i ran the tractor. The ice inside the cap was just too far remove from any bit of heat in the hydraulic oil.

 

[4630 GSTC]

Well, I finally did it! I called another Kubota dealer (not the one that I bought the tractor from) and talked to a mechanic who gave me the courage to delve into the unit. A few turns with a 1 1/4 open end wrench to start it, then I ever so carefully unscrewed the assembly from the control valve. Once the last thread was barely touching, out came the water. Probably 1/2 shot glass or so onto the floor. I slowly back it out the rest of the way and carefully took it completely off. To my amazement, nothing went flying. I dried everything with a hair dryer, sprayed it down with RemOil, and put it back together. Curiosity was killing me, so I also removed the other cap to check for water. No water, and a thin coat of grease on the spring assembly. Put it back together.
Made a makeshift cap cover from the old one, some silicone, and a 1 liter Mt. Dew bottle cap (perfect fit). Sprayed a little black paint on the cap and I think I am back in business. Nearly 4" of fresh snow on the ground and still snowing. Time to hook up the blower and go play, I mean work. Thanks to all that contributed, and hopefully this will help another.