Sinking B7100 3pt lift..

[HammerFour]

My B7100's 3pt hitch will lower on its own. Sometimes it holds position for several minutes, sometimes it starts sinking in just a few seconds. We had the tractor repaired at the dealer last summer to correct this problem but it started doing it again ( or was never fixed, I was out of the country from April of last year until January of this year so I didn't use the tractor right after it was "fixed" ).

Any hints or ideas? I am planning to contact the dealer to see what they can suggest.

 

[Freds]

I don't have any hints or ideas... just thought I'd mention the B7500 I had did the same thing. Usually over several hours. If I wanted it to hold position, like if I had the counterweight on it or I had it set at a certain height for brush hoggin, I would close the knob that controls how fast the 3 pt lowers.

 

[snmhanson]

My B7800 will sink slowly as well. I though maybe it was normal but maybe not? It only happens of course when it is up and I'm using another implements. It hasn't caused me any problems as I've gotten in the habit of checking it to make sure it is up all the way every now and then when I'm not using it. It would be nice if it didn't happen at all though. I'll keep an eye on this post to see if it is normal or not and if there's a remedy.

Matt

 

[RickNC]

I really don't think that it should sink that quickly. My B7100 will hold a vertical adjustment probably 30 - 45 minutes with a 4-foot rotary cutter attached before I need to bump it up a little. Without position control, any of them will droop eventually, but I don't think that your system is holding adjustment nearly as long as it should.

I would take it back to the dealer or at least call him for an explanation.

 

[HammerFour]

Ok, I put a new $2.69 o-ring on the lift cylinder and that helped quite a bit. The implement will still drop but much slower now.

BTW, it was very simple to replace the o-ring, remove the vertical connectors that join the lift arms to the 3ph arms, remove the 4 bolts holding the lift cylinder "head" on ( the lift cylinder head is the piece with the knob on it for directing the hydraulic fluid to the 3ph lift or to an accessory ), pull the head off, then work the lift arms back and forth to push the lift cylinder out where you can grab it and remove it.

Pull off the old o-ring ( mine was flattened a good bit ), and put the new one on, then reassemble.

Has anyone replaced seals in the 3ph control valve on one of these tractors? Are there seals? I am interested in getting this working as well as possible, so I am considering the control valve as the source of the leakdown now.