Hydraulic hiccups

[IslandTractor]

My 2007 Kioti DK40se with 500hrs has been pretty much flawless since new. Hydraulics including two rear remotes and a diverter valve have been maintenance free other than routine fluid and filter changes.

Yesterday I mowed and grappled and then shut the tractor down normally. I disconnected the grapple hydraulic lines per routine in preparation for mounting a tree boom. This morning the tractor started right up and all hydraulics worked. However, as I was backing up it felt like I ran over a rock or small stump. Tractor went "bump" then it happened again a few seconds later. I dismounted and found no rock etc and as I was checking the tractor "bumped" again. I could see it jump slightly just as it would if you ran over a rock. Engine purring along at idle. About ten seconds later it happened again and this time I was behind the tractor and saw the 3PT arms move slightly in association with the bump. Flail mower mounted but not engaged. I checked the levers for 3PT and draft control and both were in middle and 3PT responded normally to lever. It seems the 3PT arms moved (caused) each bump. Hydraulic fluid is full. Bumping continued for five minutes and then stopped. Everything works.

Any idea what caused this?

 

[oldpilgrim]

air in lines?

 

[IslandTractor]

air in lines?

I wondered about that but:

1) wouldn't air clear in a couple of passes through the system? This bumping went on for five minutes.

2) how did air get in? It's never happened before and I didn't do anything different.

 

[MtnViewRanch]

Shouldn't the draft control lever be all the way forward unless you are using the draft feature? Typically when doing some sort of dirt work, certainly not with a flail mower. :confused3:

 

[oldpilgrim]

I wondered about that but:

1) wouldn't air clear in a couple of passes through the system? This bumping went on for five minutes.

2) how did air get in? It's never happened before and I didn't do anything different.

1) it would seem so
2) dunno, why not try and disconnect all your quick connects and then reconnect. I've heard of that sometimes helping with hydro issues.

 

[murphy1244]

Shouldn't the draft control lever be all the way forward unless you are using the draft feature? Typically when doing some sort of dirt work, certainly not with a flail mower. :confused3:

+1 on that Brian, lever should be forward.

 

[IslandTractor]

+1 on that Brian, lever should be forward.

Yes and that is where the lever was when the "bumping" started. I put it in the middle just to see if that ended the anomaly.

 

[murphy1244]

Yes and that is where the lever was when the "bumping" started. I put it in the middle just to see if that ended the anomaly.

Sorry Ed,I didn't see that.

 

[IslandTractor]

Sorry Ed,I didn't see that.

My initial post was vague on that. I basically never touch the draft control as I don't plow so it always is fully forward (except when trying to figure out if it is related to "bumping".