B7100 3pt hitch...how to attack?

[timcote42]

Greetings, it's been a good tractor day today. Changed engine oil, transmission/hydraulic oil, front axel oil, front wheel oil, coolant fluid, cleaned hydraulic filter, changed fuel filter and explored this thing I bought off Ebay two months ago.

Mine came without attachments for the 3pt hitch, but I am thinking I should have one so I can buy a post-hole digger (tractor came with a BH and FEL). No claims were made about the 3pt, and I don't think it's working. When I move the lever into "raise" or "lower" implement, I hear a mild squeel, the engine slows slightly but the spindles don't budge. Neither do they seem to turn freely in any position of the lever. Incidently, just below the seat I see there is a valve that turns between two positions, one of which is capped off and one of which I think directs fluid to the 3pt. For some reason, this valve isn't mentioned in my origional owner's manual.

So...shall I tear into this or am I missing something essential? Tim

 

[Tig]

That valve is used to by pass the TPH and power an accessory circuit that you would connect where the cap is now. The arrow on the handle should point to the left of the tractor (away from the cap)

 

[timcote42]

Okay, it is pointed away from the cap. The hitch isn't moving on command. Clearly, something is wrong either with the control valve for the 3pt, the cylindar, or the pump. Where would you start? Is there a simple way to test the pump, or am I best advised to just start tearing into the valve and/or cylindar assembly? Tim

 

[Tig]

Looks like you do have some sort of problem there. I have not had to repair my TPH so I have no expereince there.
My guess is that the mild squeel is the bypass valve. When my TPH reaches it's limit the squeel is quite loud.
I was thinking that you could test the pressure at the cap, but if operating the TPH loads the engine it would seem that there is pressure there.
Do you have a maintenance manual and parts catalog? Until more experience shows up here, that is a good place to start.

 

[charlz]

There is an adjustment bolt/locknut (I think on the right hand side when sitting in the seat) that controls how fast the 3pt drops. Should be right around the cap/valve you were looking at earlier. I suppose it is possible this is all the way open and simply passing all the fluid straight back to the sump. Manual says the gap between the bolt head and the lock nut should be about .1181in.

Also could be the o-ring on the 3pt piston is so totally shot that it is just passing fluid. Here is a post I made about fixing mine: http://www.tractorbynet.com/forums/parts-repairs/88048-repair-kubota-b7100-dropping-3pt.html

Mine actually moved though, just wouldn't hold an implement up.

BTW, I was successful in getting a longer lower link pin and leaving the backhoe brackets on full time. I have some pics here somewhere. Makes changing over to the hoe/taking it off almost as fast as changing an implement.

Charles

 

[timcote42]

Thanks to all. Okay, will start with the adjustment bolt clearance, look for any other valves near to the pump that might be turned the wrong way, then dig into that piston to check for O-ring deterioration.

Charlz, just for update I took my swing cylindars for the BH to a hydralics shop. Cost: $130/cylindar for pin extraction, repacking and blasting/painting the outside. They decided my rams are okay, the nick notwithstanding. Not a great price, and I'd rather do it myself, but this little frustration has taken too long not to throw a little money at it and make it all go away....

Tim

 

[Egon]

If the three point is in the up position and will not lower I'd suggest a look at the internals may be in order.

There is also a control under the right side of the seat that sets the points at which the control lever cuts out.

 

[Harry c]

Remember the 3pt is gravity down. If it is all the way up and you try to lift all it will do is squeal. Push the lever down and have a cohort push down on the lift arms and see if they will go down. Make sure the drop speed control valve is turned all the way out.