Hey all. i've been trying to diagnose what is wrong with one of our machines. The throttle does not work, operators are using it with a piece of wire attached to the throttle to manually put it into an operating position (lol) I went today to take a look. The throttle actuator is a stepper motor with 2 connectors, 4 wires on one and 3 wires on the other. I measured throttle stepper motor the resistance in both phases and its 6 ohms, the same, and the voltmeter displays 0L when measuring cross-phase. Im no expert on the electrical side of things, so im not sure if that means the throttle motor is busted or not Another thing that I checked was the voltage on the 3 pin connector, cause I saw somewhere that this was the limit switch. The voltage was 13.45 volts and it did not vary when changing the throttle switch from inside the cab. However, the connector had only 2 wires coming from the source voltage (the ECU?) so this was rather inconclusive. Couldnt check the switch in the cab cause it requires a special tool to remove the bolts. The machine serial number is in the picture attached below, if anyone knows whats next in fixing this thing
1. Are there any errors on the monitor? 2. Does the throttle try to do anything with the key on or running? 3. Have any parts been replaced already?
1) The monitor shows a thousand codes, some of the buttons don't even work, some of these.codes are false positives (it says low coolant level even though it's full) so can't rely on it 2) When the key is put in the ON position, yes the throttle motor rocks back and forth for a few seconds then stops. 3) not yet
The coolant level switch is in the over flow bottle. It can be bypassed with a jumper. The metro controller on these machines can fail usually when this happens the monitor will show cpu fail or metro control fail. The limit switch on the stepper motor just connects a ground, just ohm between the two wires and see if you get a connection when you rotate the motor. If the linkage was removed from the splines on the stepper motor an A adjustment will have to be performed to calibrate its position. What does the throttle do when it's running
the throttle motor rocks back and forth when you first turn the ignition key on, but then it stops working. the switch and all the electrical side of things is okay cause I've got it checked. This machine has had the fuel pump replaced, im not sure if they removed all the linkages or not when they did it, but most likely we will need to calibrate it then. How do we do it?
There is a lengthy procedure I could look up tomorrow but hold mode till the monitor powers up then hit buzzer stop for 5-10sec. Monitor should go to adjustment screen hit buzzer stop again should go to gap stop. This moves the stepper motor to the engine stop position you need to adjust the linkage so there is a .1mm clearance between the stop bolt and the arm. Hit buzzer stop again and it should say start engine, after started hit buzzer again and it will start running the throttle up to full throttle. After it completes it will tell you max rpm reached. Then power down and restart. What does your monitor look like oval or rectangle
You are right about the injection pump link length. In this case, you must perform a type A adjustment. You can refer to the attached file for more details. Good luck.
does anybody has an electrical schematic for this machine? thanks.
Hope to be helpful. Good luck.
hey man, thanks a lot!!!!
can a pressure filter be installed after the pump, but before the valve block? this machine is not working properly after fitting a new pump + new fluid + new return filters after a pump failure. it seems weird but movements get stuck and wiggling the joysticks sorts of "unlocks" the machine, then some other movement gets stuck or slow, rinse and repeat. its very random, and all the sensors are reading fine on the monitor at least. machine is also reportedly slow with tracks, and the hydraulic hammer gives a soft punch, but it might all be related to the issue described first. after fixing the electrical issues to me this is mechanical. but is the main valve block the one giving issues? im not familiar with this. I did the procedure to set up the pumps and all was ok. debris from the pump that grenaded might be screwing it up?
hey there, you seem knowledgeable of the kobelco machines. i am now facing a weird issue with it, maybe you can tell me whats going on... after fitting a new pump, cleaning the valve block, spools, etc and fitting new fluid. there is one problem now, when working with an hydraulic hammer, the pressure of both pumps drop to 14-12mpa randomly. but if you shut off the engine and do the a-b-c adjustment the pumps load up normally to 32-33 mpa. i've been told this could be the chassis module screwing it up. but im done just throwing money to it...I need to confirm if this is true as the downtime to fix these things can be over a month, and a new one goes to $3500 around here. thanks
Hydraulic hammer / Rock Breakers are usually set up for around 15 MPa for the max relief setting and 2-2.5 MPa for the nitrogen charge. Slow or weak operation can be low hydraulic flow supply or low Nitrogen gas pre charge at the top chamber of the Hammer. Conflux switch should be set to single pump flow.
It was refilled with nitrogen prior testing. Also it is not only the hammer but the boom and tracks are slow, pump pressures are 8-9mpa for p1 and 13-14mpa for p2, they don’t seem to go higher than that, however doing the a b c adjustment shows the pumps can go as high as 36-38mpa each. what is the conflux switch and how can I verify it’s set to single pump?
Kobelco have a smart feature in their diagnostic display that allows you to monitor specific sensors and solenoid outputs that operate for each function. You can try using this feature to carry out some diagnostics to check and see why the boom and travel system is slow. The same fault could also be affecting your auxiliary output as well. It is covered in the repair manual which I assume you already have. I will email you the sections of interest from the manual.
ahh gotcha, yeah there are differences to what I’m experiencing in the machine, will check on Monday. Thanks a lot man