Undid a pilot hydraulic line and lost forward movement.

[Toddgarage]

Think about it like this. A carburetor, like a hydraulic system, has a fair number of adjustments on it and messing with them those adjustments can cause issues. It’s important to slowly and methodically go at the problem without twisting all the screws around and changing the original settings.
-did you check pilot pressure before this?
-do you hear the drive motors making noise in forward but just not moving?
-do you have pressure leaving the joystick?
-have you checked all electrical systems?

In my experience: the joystick takes pilot pressure from the charge pump (accessory pump), 200-400psi and then distributes that pressure to the drive pump or loader controls. The pressure after the joystick will swash the drive pumps into action and create pressure/flow for the drive motors. The further you push the joystick the more you swash the drive pump and the more drive motor action you get. (This is a simplified explanation.)
-A chunk of o-ring or debris could be preventing the drive pump from a swashing in a particular direction.
-Maybe you’ve changing the flow or pressure settings on something by screwing those screws tight?

I’ve been here. It takes time to trace your procedures backwards and figure out the root cause. Then your can truly figure out what was wrong in the beginning.

Work safe, Todd

 

[Mark250]

The resolvers are just single ball bearings .250 i think. When you undone the allenkey screw did you lose that ball???

 

[antpoo]

I found the joystick to be very durable and robust, I tampered with all four of the Allen key screws thinking it was as way to undo the resolver valve, yet it did not upset reverse and right turn function.

I can see by the diagram above that
If there is a blockage in the resolver it is in the D and C Port.

However when I push joystick in forward I feel absolutely zero resistance, no feeling of any fluid moving through or engine pump noise, which makes me think maybe the spool/plunger is malfunctioning.

I definitely have pilot pressure to the joystick, so it’s either locked up because plunger spool not aligning correctly to allow flow to the resolver, or the ball resolver is seized creating a check valve that won’t allow flow toward to main pump.

I’m taking a day off. Has been 3 days non stop trying to solve this problem. But I’m getting closer, And learning a lot.

 

[antpoo]

Well thanks to me I have finally found the problem after days.

I lost forward control after unscrewing a ball resolver Allen key ball seat that I thought was how to separate the resolver from the upper valve.

What actually happened was as I unscrewed it, it sheared in half and upset the ball seat position causing the check valve to fail, instead causing fluid to deadhead and neutralise the C-port which controls forward and left function.

It doesn’t look like a replaceable screw so a whole new resolver needs to be ordered. $715 including oring set.

 

[Toddgarage]

It’s always nice to find a problem and relate it to the root cause of the original issues.
I can’t think of anyway to repair that… also don’t know if they are rebuildable. Either way, less than 1000$ to move forward, not to bad.

 

[antpoo]

It sure is. It took 5 days of stripping and rebuilding over and over, and studying schematics, and getting covered in hydraulic oil, I was always so close, but no amount of reading was enough to teach me that the screw had sheared in half.

Had to learn that the long slow way.

But even though I knew I was up for $700 on finding the problem, The relief of actually finding it was definite.