Hi, I have an EX200-3 it seems to have lost control of the pump displacement. Sometimes the engine is under load and stalls when any leavers are touched and sometimes it runs nice but hydraulics are really slow. I have been over it and tested voltages to and from some of the sensors and also harness checks. The voltage readings into the 2 solenoid valves are all over the show. sometimes reading a constant 24 volts and sometimes not reading anything even when hydraulics are used. Also the wire coming out of the angle sensor is only reading 3.4v where its supposed to be 4.5v +/- .05. Ive tried turning it on the adjustment bolts but can't get a larger reading than 3.4v. Ive tried replacing the sensor with another second hand one but its giving the same reading. I'm wondering how critical this is and if it can be the cause of my problems. I'm also wondering if it might be the PVC playing up but the light on top is blinking regually as its supposed to. Any help would be much appreciated. thanks
The pump angle sensor will only go to 4.5 volts when the pump is at full swash. There are 2 pump displacement solenoids on top of the pump .One swashes the pump and the other deswashes the pump.Take off the harness connectors and switch them.At an idle you should hear the engine start to load up.This is when you adjust the pump angle sensor.Loosen the 2 allen head bolts but leave them snug and turn the angle sensor.When you tighten them up you may change the voltage reading (they are that sensitive)so you may have to play with it to get the right reading.
Hi, thanks for that. It will probably explain the angle sensor issue. Do you know how much voltage should run to the displacement solenoids? It seems like everything else which is getting power from the PVC is part of a 5v system but at one point both the solenoids were reading a constant 28v except for one wire on number 2 solenoid was reading about 13v but changing. Just wondering if they were supposed to be 5v then where is all that voltage coming from, maybe a short somewhere. Im away from the machine at the moment but will get back there in a few days and was thinking to start by setting that angle sensor and if that doesn't fix it then maybe start running some wires directly from the solenoids up to the PVC. What do you think about that? cheers
How may hours do you have on the machine and has the pump ever been rebuilt or replaced in the past to your knowledge? I have seen the servo piston bores worn out on higher hour units. I also remember something about some bearing races for the swash plate that would get fretted and cause the swash plates to get stuck at times. Neither issue will leave any debris in the return filters. So if checking the electrical and electronic issues come up good it might be time to go through the pump.