3-Point Hitch siromer wont lift

[dewson]

Well IT could be the diverter not returning to main position to feed 3PH, or the rotary vane pump/steering assembly is leaking past, allowing flow out of the diverter which keeps it diverted to the priority/steering port.

One way to break this tie, short of swapping one out, might be to plug that priority port, and deny flow to steering the same way the steering box should when you are not turning the wheel. If working properly this should make the diverter valve flow fluid to the 3PH. You could plug the port to the steering fairly easilly with a metric bolt put in place of the hollow banjo bolt. Doing this would have one of two outcomes
1. The diverter will function as designed and send fluid to the 3PH, indicating the steering vane pump/valve is the issue.
2. The diverter valve will stay stuck in divert. Since this port is now blocked for testing, the pressure will build till it exceeds the relief pressure in the diverter and fluid will flow out that 4th diverter port . The 3PH will continue not to function. You may hear the added load on the engine, but it should only build as much pressure as the system does when you turn the steering out to one steering limit or the other. On mine it builds about 500 PSI. To confirm that the diverter relief function is working properly before you block the port, you can start the engine and while idling, turn the steering all the way to a stop and see how the engine responds. You should hear it load down a bit when the steering reaches an end stop. IF it stalls the engine at idle, it may not be relieving properly, and may not be advisable to do the blocked diverter port test as without a relief, would completely dead head the pump with a malfunctioning diverter valve.

Hi thanks again for the reply maybe there is a fault with either the steering ram or the column because as you say with yours the flow doesn't cut off until you steer , with mine the flow is returning to the reservoir through the pipe on the left without touching the steering wheel but it appears to steer fine to me, looks like steering circuit is continually flowing pumping. On the hydraulic cover under the seat I removed a small cover with three bolts and can see the oil returning with engine running and nobody touching the wheel . Could be the seals in the steering ram bypassing ? thanks again for your help Dewson

 

[RonMar]

Fluid should only be able to get to the ram when you turn the wheel. If fluid was headed to the ram it would be pushing the wheels left or right. If the ram was leaking past, the wheels would not turn or turn sluggishly when you turned the wheel.

In thinking about this some more, I went out and pulled the output line on my steering valve/rotary vane pump to check, and surprisingly(well not really when I think about it) there is fluid flowing out of it whenever the engine is running. So some assumptions I was making earlier are incorrect. And if I had thought about it a little more, it probably would have come to me then. You need flow to control flow, so there is always some flow thru the steering valve. It is when the steering is operated, that more flow is demanded from the system, and the diverter shifts more flow to the steering, denying flow to the 3PH in the process. SO either the diverter is faulty, or the pilot flow thru the steering is excessive, causing the diverter to remain diverted to meet this demand. After this revelation, I am thinking the only way to troubleshoot this further is to swap out a part. My first choice would be the diverter as it is less expensive and easier to access and swap. Here is some additional info on the diverter from Johns Jinma website.
DiverterValve

 

[dewson]

Fluid should only be able to get to the ram when you turn the wheel. If fluid was headed to the ram it would be pushing the wheels left or right. If the ram was leaking past, the wheels would not turn or turn sluggishly when you turned the wheel.

In thinking about this some more, I went out and pulled the output line on my steering valve/rotary vane pump to check, and surprisingly(well not really when I think about it) there is fluid flowing out of it whenever the engine is running. So some assumptions I was making earlier are incorrect. And if I had thought about it a little more, it probably would have come to me then. You need flow to control flow, so there is always some flow thru the steering valve. It is when the steering is operated, that more flow is demanded from the system, and the diverter shifts more flow to the steering, denying flow to the 3PH in the process. SO either the diverter is faulty, or the pilot flow thru the steering is excessive, causing the diverter to remain diverted to meet this demand. After this revelation, I am thinking the only way to troubleshoot this further is to swap out a part. My first choice would be the diverter as it is less expensive and easier to access and swap. Here is some additional info on the diverter from Johns Jinma website.
DiverterValve

Hi Ron at last the hydraulics are lifting, the pump must have had enough pressure to work the steering but not enough to open the diverter, I took a chance and changed the pump and filter and now my problems are solved, thanks for your help and support regards Dewson