Backhoe Is "Creeping" of the FEL & Backhoe Normal ???

Don_Curley · Jul 4, 2001

Is \"Creeping\" of the FEL & Backhoe Normal ???

I asked the sales manager at my Kubota dealer whether or not the LA402 loader and B4690 backhoe would maintain their "raised" positions over a period of time (e.g., overnight), after shutting-down my B2910. Although I had initially assumed that there would be a certain amount of hydraulic system pressure "bleed-down" (and hence, lowering-down of the loader and backhoe), the sales manager indicated that this should not happen and that the hydraulic system would maintain the last position of these items over an extended period of time. Well, either his input is less than accurate, or else something is wrong with my tractor's hydraulic system, because both the FEL and backhoe "creep" to lower positions after I shut the tractor down (especially after an hour or two ... and most noticeably overnight).

If on the other hand, this "creeping" is normal, how the heck are you supposed to come back to a backhoe that has been removed (for the use of other rear implements), and properly back into it for reattachment to the 3PH ... if it has "relaxed" into a postion that does not allow for this?

Don

glennmac · Jul 4, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

I have had a BX and a 2910 and both would show noticeable leakdown of the FEL and a weighted 3ph after 24 hrs. I would say this is normal. I've never noticed it after a "couple" of hours. But to suggest that it would not happen at all is, I think, simply incorrect. I dont know about backhoes, but there is a recent thread on backhoe leakdown remedies.

Bird · Jul 4, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

Don, a few years ago Kubota replaced all 4 cylinders on the FEL on my B7100 because it would gradually lower even with the engine running. At that time, they gave me some number (which I don't remember) that would be "within specs"; i.e., for the FEL to lower at some specified speed over time without the engine running is considered normal. Mine happened to have been well outside those specs. They first thought it might be leaking back through the valve, but eventually determined it was defective cylinders instead.

Bird

Jag · Jul 5, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

Don, leak down was one way to see how much a tractor was used. I remember several old-timers looking at a Ford 8N or 9N and checking how fast the 3pt would bleed down. It is not a good idea to leave any hydralic attachment up. Every manual I have ever seen tells you to lower all attachments to the ground before leaving the tractor.

On disconnecting the BH. I always lower mine down on blocks for safety, and pull the outriggers up and tie them to take up less space in the shed. To reatach you back up near the BH, hook up the pump or quick-connects to the tractor and use the hydralics to pick up the the BH, back on under and lower the hoe down onto the supports and make all the connections. It can be a little tricky at times. You really need a level place and good access. I dropped my BH off once on a slight slope and it took several men, a small boy and old mule to rehook it.

kubmech · Jul 5, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

Don, the creeping you have described is normal. Most of the leakage is past the valve spool with a very small amount past the cylinder seals. I'ts acceptable as long as it is'nt enough to cause a noticeable power loss or excessive drift down while operating. Loader should be stored with loader bucket flat on the ground and backhoe stabs on the floor and boom against the boom lock.

frank_f15 · Jul 5, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

kubmech: then why is it that my 98 b2400 and my my friends kubota 14 years old (can't remember the model, but slightly smaller) when they are sitting side by side, his fel does not drop an inch while mine creeps down, it will drop a foot in 1 hour. also have seen a neihbors old ford parked for days with the fel in the same raised possition. would seem to me that if everything is holding the fel should not drop. would appreciate any additional info, before i call my kubmech./w3tcompact/icons/smile.gif

kubmech · Jul 5, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

That's a little more info than your previous post. Mostly depends on the guy that machined your valve housing and spools. Although I've seen em' vary by that much, and still be "in spec'', kubota seems to refuse to publish drift specs for some reason, but J.D. has, and for a comparible loader/backhoe your well within limits, both companies use Danfuss or husco valves, and right now, I think, Husco is the valve manufactorer for both, and we have seen our share of problems with the Huscos. Could be something more. Have it checked out.

Don_Curley · Jul 6, 2001

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

Thanks to all for the input. When I was talking to the service manager at my dealer today (about my engine knocking problem described in another thread), he acknowledged that a certain amount of leak-down on the FEL and backhoe is normal (and basically said their sales manager was full of it for telling me that leak-down would not happen). He mentioned that some commercial construction equipment uses special hydraulic valves and cylinders that have extremely low (if non-existent) leak-down rates ... however, if Kubota had used those items, the purchase price of our tractors would have skyrocketed by several thousand dollars.

You know, I wonder, would adding some Viagra to the hydraulic system at my 50 hour service cure this problem? /w3tcompact/icons/wink.gif /w3tcompact/icons/laugh.gif

Don

atk_man · Feb 26, 2002

Re: Is \"Creeping\" of the FEL & Backhoe Normal ???

I am noticing more and more this creeping problem in my 79 B7100. The problem is that it is not consistent. Sometimes it will "creep" down quite fast. Sometimes not at all. Sometimes it seems to vary with how high the loader is. Sometimes it seems to happen more after running the engine full throttle for a while. (This tractor has the pump at the front.) One thing I have noticed is that after running at higher rpm's there are some small air bubbles in the resevoir.

My question is where do I start? Rams? Pump? Control Valve?

So far it hasn't stopped me from doing the work I have to, but I do need to develop a plan of attack.

Thanks.