Sudden Slow 3 PT

[Smalljobs]

I'm approaching 100 hours now on my Jinma 284 and suddenly the TPH has slowed down. For the first 60-70 hrs I was using a Jinma chipper having a posted weight of around 800 lb. I was always raising and lowering the chipper when I moved the tractor around and I could always raise it at idle.

Now I have a Rubbermaid barrel counterweight with 7 bags of Sakrete weighing 80 lb each and some misc hardware totalling around 575# plus the 7 gal of water used @ 8.3 lb/gal = 630 lb. The cross shaft goes through the middle of the barrel. When I finished the barrel 2 weeks ago I'm pretty sure I could raise it on "idle". Now it won't budge until I raise rpm to around 1200.

In the last 2 wks, I've been doing a lot of loader work on an up and down incline and find the power steering to be occasionally sluggish in each direction. The first time it happened I raised the wheels with the Koyker bucket, cycled them back and forth and it all cleared up.

I have not changed the 3 PH adjustment for lift range or stroke.

I wonder if the sluggish steering and now slow TPH are related and what is going on? I'm concerned it may worsen and I'd like to get this resolved before winter. On top of this, I have all the fluids for the big fluid change but don't want to change anything until I understand the TPH problem.

Loader and steering work fine but TPH problem persists.

Any ideas would be greatly appreciated.

 

[greg_g]

Sounds like the counter-weight sits farther away from the tractor than did the chipper. Lift capacity is based upon the center of gravity of the load being ~24" behind the lift point. All else being equal, if the center of gravity of the counter-weight is farther back than the center of gravity of the chipper - it's going to represent more "weight" to the hydraulics.

//greg//

 

[Smalljobs]

Thanks Greg,
The CG of the counterweight is 25" back from the C/L of the toplink pin closest to tractor. It's 32" from the C/L of the TPH upper arms that do all the lifting. That's the point where the arms exit from the housing.

The heavier (borrowed) Jinma chipper is no longer here and I don't recall the location of the pins and especially the flywheel.

 

[Diamondpilot]

Steve, I have seen your counter weight and its not a CG problem. Think of what a Bush Hog weighs and how far back the CG is on these things. I put my money on one of 3 things. Since your tractor is a newer model I would first change the suction side spin on filter. Next thing would be take apart the priority valve and clean it up. Last and hopefully its not the case is a pump that is going south.

Chris

 

[erj]

Steve,
Did Bolton Power change out the original fluids before you got it?
RonJ

 

[Smalljobs]

Bolton Power did all the right things, changed fluids, adjusted clutch, etc. Now it's time for my own fluid change.

 

[erj]

Steve,
Do you have a pressure gauge to tell what pressure you have in the hydraulic system?
RonJ

 

[Smalljobs]

Ron..tks,
Pressure gage is on my workbench and just arrived. More to follow.

 

[greg_g]

Thanks Greg,
The CG of the counterweight is 25" back from the C/L of the toplink pin closest to tractor. It's 32" from the C/L of the TPH upper arms that do all the lifting. That's the point where the arms exit from the housing.

Actually that 24" is measured from where the vertical link pins to the lower lift arm. Too bad you don't have the chipper anymore to see if it still raises faster. If it didn't, you can reasonably conclude that the problem is hydraulic. But without something else to compare to lifting the counterweight, we're still at the guessing stage.

//greg//

 

[bjr]

Why can't this be as simple as a blown oring on the power piston of the 3pt? bjr

 

[Bob Rooks]

Why can't this be as simple as a blown oring on the power piston of the 3pt? bjr

A blown o-ring or seal wouldn't necessarily slow it down or require more power to move it, but would definitely prevent it from staying up.

 

[Smalljobs]

For some reason the problem has gone away by itself. Maybe the machine knew I'd been talking to Chris and was about to perform some hydraulic surgery on the priority valve so it suddenly cured itself.

 

[Bob Rooks]

A wise machine indeed, but time will tell.

 

[greg_g]

Maybe the machine knew I...was about to perform some hydraulic surgery on the priority valve so it suddenly cured itself.

I believe that's a good thing. Sometimes over-thinking an issue can lead to more problems than one originally intended to fix.

//greg//

 

[Diamondpilot]

Glad it went away. Now more seat time and less time wrenching.

Chris

 

[Brad_Blazer]

Good news. If it comes back you know it's not the pump. You said you were using the loader on a slope. Depending on the vent location (not in the top center of the tank), on some tractors (like mine) the fluid will get pushed out of the vent when working on a slope. So it may be a good idea to check the level.

Also, when you change fluids start draining by disconnecting return line at the pump to make sure you are getting free flow.

Brad