420 dead hydraulics

[MarkP]

About the middle of this past week I started the 420, lifted the blade just fine and drove it over to the barn to store. Today I needed to move it so I started it up and now the blade won't move at all. No up, no down, no nothing. Plenty of hydraulic fluid and it looks nice and clean. The day I moved it to the barn it was about 25 degrees out and it worked fine so don't think the fluid was frozen or anything odd, it's about 40 out today. This is a single cylinder system and has worked just fine in the past. Any ideas what would make the hydraulics stop working suddenly like that?


Update: So after a few hours I went out and started it again. This time when I tried the hydraulics they lifted the blade. The hydraulics groaned a bit the first time or two like it might have had an air bubble or low fluid?? Again, the hyd. tank reads full. After a couple times up and down the hydraulics ran smooth and quiet as they should. So back to the question, anyone have an idea of what may be going on here?

Mark

[JD440ICD2006]

A long shot but it sounds like there could be moisture in the hydraulic system.
Moisture will do strange things. Sometimes it will freeze and cause problems and then other times it is not in the right place or does not freeze enough to stop things.
If it has been more than 6 months since you drained the hydraulic system completely, this may fix it for a while.
The reason I say "for a while"? I used to keep my "toys" outside at times. I have learned that keeping "toys" outside can create many issues, especially in cold weather.
Some folks think that if it has not rained, there will be no moisture issues. What really happens is this. Mositure is created by the heating and then gradual cooling. The colder it is, the more moisture is created in places that you do not want water. Humidity is also a factor.
You will still get moisture from the cooling, but if it is a place that is not freezing (outside), at least it will not stop your hydraulics.