Slack in FEL dump circuit

[PaulT]

I recently noticed that my 402 FEL has play in the dump rams after the tractor sits for a few hours. This never happened before. I got the 2710 in May and have used it often over the summer. I only noticed it about 6 weeks ago. If the bucket is off the ground, after a few hours, or overnight, I can rock the bucket back and forth with my hand. The rod is moving in the cylinder and all the pins/bushings/etc. are tight. Starting the engine and rolling back the bucket tightens up the hydraulic circuit, and it doesn't slack up again while I'm using it. It really isn't a problem, but I'm curious why it just started recently. I haven't noticed any leaking aroung the ram seals. Any thoughts??

PaulT

 

[Mike_Dumond]

Paul, you may not be leaking fluid out, but you may be sucking air in. Check the fittings, and always park with implements lowered. That way, neighborhood kids can't accidently lower them on their friends.

Keep the greasy side down.
Mike

 

[Bird]

Paul, mine does the same thing (I assume you're talking about with the engine off). I don't consider it anything unusual or important. When I start the engine and move the bucket that takes the slack out of it. Hmmm . . ., of course you're talking about leaving the bucket off the ground and I don't do that. When I park it, I let the bucket down, and when I park it overnight, I not only let the bucket down, but then move the joystick in all directions after killing the engine to relief any pressure in the lines. So maybe I wasn't comparing apples to apples here./w3tcompact/icons/wink.gif

 

[PaulT]

Bird,

I, too lower my implements at the end of the day (box blade/FEL) and release the pressure in the valve. Its just that sometimes I shut off the tractor during a project while I use a rake or shovel for a while/w3tcompact/icons/shocked.gif! It happens in either case, as long as a few hours have gone by. Sounds like we have the same symptoms. Did yours always do this, or did it happen sometime after you started using the FEL? I think I must be sucking in some air somewhere to get the play, and using the curcuit purges any air that has entered. While I don't think the air in the system is a problem, I think the location of the air leak (if it is a leak) could be - seals or something that someday will leak fluid out instead of leaking air in. The fittings are all tight. Could the quick-disconnects be the culprit? They don't leak fluid under pressure, so I don't think they would leak air when pressure is released.

PaulT

 

[Bird]

Paul, I'd be afraid to say for sure, but I think mine has always done that, and I believe the one on the B7100 did, too. I've just kind of considered it normal. Another thing I've found is that the first time you start to curl the bucket back, when it hasn't been used for awhile, is that it may "dump" forward an inch or two first before starting to roll back. So if I intend to move something where small increments are critical, I always move the bucket both directions first.

 

[Joe_W]

My 2910 started doing that recently while I was using it. I have over 200 hours of hard work on it since I received it on June 8th of this year. I first noticed the looseness while driving over rough ground with the bucket empty. I saw the top of the bucket jump up and down with the bucket in a mid-curl position. I locked the brakes, got off the tractor with it running and was able to move the bucket up and down very easily by hand at least 4 inches. I noticed that the curl cylinders would move about an inch in and out when I did this. I checked the pins and they seem tight, and the fittings have all been greased regularly. When using the loader all seems to work as normal, so I haven't given it too much thought. When I first got the tractor I went through some leakage at the couplings on the control valve, but those were repaired with new o rings and I have not seen any leaks since then. Maybe Kubmech can shed some light on the situation. If there is a problem, now would be an ideal time for me to take it to the dealer, as we are ankle deep in mud right now.

Joe W.

 

[bcarter]

Paul,

I've got the same set-up and the same symptom. Can't say that its always done it but I certainly have noticed it recently. My bucket teeth stick up a little when the loader is on the garage floor - If I step on the teeth (which sometimes happens as I try to sqeeze around the bucket when the garage door is closed) the bucket will move a little.

I was starting to wonder as you did if this was normal or not. Given that more than a few folks seem to have this problem, its starting to look that way.

Bill

 

[Youare]

I have a Kubota L3000DT with FEL with about 30 hours on it. I noticed the same thing with the bucket sitting on the floor when I steped on it it rotated very freely. I have even noticed that when the tractor is running I can take the edge of the bucket and rock it by hand. When I used the front edge of the bucket to back drag some dirt once a little down pressure made the bucket roll. I didn't think this was normal but thought it may need time to break-in.

All my other hydraulic experience tells me that you can't compress a liquid and if the valve to that side of the cylinder is closed it should not allow the rod to move in te cylinder. Then I thought maybe there was some type of relief valve in the line to prevent damage. I would like to know what is normal.

Randy

 

[kubmech]

Slack in the hyd. circuit after sitting is normal. You're looking at a few combinations of things that will cause this. Hot fluid cooling over a period of time as well as normal leakage in the circuit (esp. when cool) Cylinder seals are not perfect and do bypass slightly (very slightly) the loader control valve spool is just a metal to metal seal and will bypass over a period of time. It does'nt sound like you have anything to worry about.
As far as play in the bucket while in use, some of you have 3 position loader valves and some of you have 4 position valves. The difference is (on the newer machines) The 3 pos valve has a regen circuit which is always activated in dump, while the 4 pos valve only activates regen in the far right detented position. If your not activating regen during the dump cycle you will have play in the bucket cylinders.

 

[PaulT]

Thanks, Kubmech

I'm sure I speak for everyone here when I tell you how fortunate we are to have a bona fide Kubota mechanic willing to provide free consulting and advice. If you ever make it to upstate NY, I've got a hot meal and a cold beer with your name on it - its the least I could do. Its people like you willing to contribute your knowledge that makes this site so great!

PaulT