I am having problems with my personal boom truck. It is a stinger II TC-125 1. The hoist has quit working. All other functions working. I have moved the hoist hoses to the extend section and the winch works off that section. All the valves including the hoist valve are in one bank, But the hoist appears to be working off a seperate section of the vickers pump on the pto . Also I have pilot pressure to the hoist valve. Any ideas or explanations of the hyd circuit would be greatly appreciated.
I have seen one section of the pump lay down , if that's happened be careful the junk can pollute the whole system . You would be correct the Winch on some models has its own section .
Quite often the pump has a section just for the winch. If the hoses are the same size, could try putting the hose from the other section of the pump onto the winch section of the valve, that will tell you if it is valve, and/or pressure relief, or pump. You might also want to try running a hose from the winch section of the pump to a pail to check for flow volume. If it is flowing enough oil, it might be that the pressure relief failed, and is dumping pressure back to tank. Only other thought is that the o-rings on the spool of the valve failed, and the oil is going from pressure port to return, no matter what position the valve is in, but I think that would be more unlikely.
hoses can collapse internally, thus acting like a valve closing .
The hoist has a 1'' pressure hose and the other is a 3/4. I will have to make some hoses and try the swap because I have already pulled the pump once and could see nothing wrong with either cartridge. However I keep coming back to the pump. The thing that is blowing my mind is the valve section. It too has been disassembled. Two basically seperate pumps both flowing into the control valve without a mid inlet section? The part of the pump that works every thing except the hoist is set up as a power beyond circuit for the outriggers. So how can the main control valve be a power beyond valve and not at the same time? What am I missing? This crane had boom end controls for a bucket and they have been bypassed long ago. However on the hoist section there are three 1/4 "pilot" lines when only two are needed on the other valves. At least one or the hose come from a valve mounted on the side with the swing motor, I have no idea what that valve is. There are no electrical wires to this valve, only many hoses and what appears to be screw in check valves. Could this be for some sort of spool to change from power beyond to not? I may be way ahead of myself. I need to start with swapping the pump hoses!