Hi all, I have a problem on this machine that is doing my head in. I would like some advice before I start taking apart pumps and regulators. I get no pressure from pump 2. So swing and left track are not working. Strangely, when I press aux pedal, but only towards me, it starts working. Also for some reason, pump control pressure is always 40 bar, meaning pump should be on maximum flow. So one side of Aux is somehow making the pump work, or I am activating some combined flow somehow. Any ideas? Thanks!!!
Is that a reading from a gauge, or the monitor? If from the monitor, I would confirm control pressure with a gauge. That depends on whether you have the 2 pump combined flow kit installed or not.
Both, monitor and gauge. As soon as I put safety lever down, I get 38-40 bar. Strange is, only one side of aux pedal makes pump work. But control pressure doesn't change when I press it. Pump 1 for example, has a few bar of control pressure, and it starts rising as I move the joystick. Pump 2 has 38-40 straight away, and it doesn't change. I can see that joystick pressure rises as I move it, but this does not affect the pump. From what I see, there is non return valve at the pump, so combined valve can not make pump pressure rise.
Pump #2 provides power for swing, left track, aux. attachment and ARM too. I didn't see you mention how has ARM works. Also, where did you measure the control pressure of pump #2? Please note that to control pump number 2, in addition to the pressure from the signal control valve, it also has a "Maximum Pump Flow Rate Limit Control Solenoid Valve" to control it.
Arm works, but arm has flow from pump 1 as well, that is why it works. With gauge, I measured where hose enters the regulator (on top of the regulator), but on the monitor same pressure is displayed. And monitor pressure is after the flow limit solenoid valve, PC2 on the hydraulic diagram. I tried unplugging both flow limit and torque control solenoid as well, but no change. I don,t understand why pump starts working when only one side of aux pedal is pressed. It may be because of combined flow, but I should not see pump 2 pressure rising because of the non return valves. Except maybe that valve next to aux spool, but I can not figure out how it works. If the control pressure is 38-40 bar, straight after I put safety lever down, that it self is a problem I think. That puts the pump on the max flow. Or it should at least. Which leads me to believe that regulator is faulty, or that oil comes to dead shut and has nowhere to bleed. Again, regulator problem. But also, pump seems to be working when that AUX pedal is pressed. Unless I am reading pressure from pump 1 backfeeding to pump 2 somehow. Is there a diagram which shows which hose is connected where on the pump regulator and control block? I have diagrams, but they don't show actual connection position on the valve or regulator.
You are right. I think that you should solve this problem FIRST. when you press the AUX pedal, the pressure from pump 1 flows to pump 2 by closing the "auxiliary flow combiner valve" as shown in the attached diagram.