Our Hitachi Ex200-2 has started to have intermittent erratic track speed and underpowered hydraulics. We replaced the DP sensor a few months ago but it never solved the problem. The machine will run fine and have strong hydraulic power to all controls for awhile and then something changes and the track speed increases a lot and all of the controls become very jerky and underpowered, sometimes even killing the engine under load. You can hear the pump working hard as if the cylinders on the boom aren't evacuating. Does anyone have any suggestions on what could cause this. The were some wires damaged a few years ago when the muffler rotted out and melted some of the sheathing, but we have tried to isolate all of the wires again now. Any help would be greatly appreciated, Thanks, Angus
Hi Angus, It sounds to me like there is still a wiring issue in the back of your machine. What is happening when your symptoms start is that your PVC (Pump Valve Controller) signal is either not getting to the pump solenoids or it is getting wrong information from a sensor on your machine, in this case most likely the Angle sensor. When this happens, the pumps go to full stroke, causing maximum GPM output and in turn all your speeds will increase to full. It will kill your engine because it can't keep up with the power now demanded by the pumps. My EX200-2 had the exact same issues, replacing the wiring harness was the only way I was able to fix it. I spent days trying to fix the wiring harness but it never worked for more than about a minute or 2, then it never worked again until I replaced the harness. If you're lucky, your machine has a separate engine harness as that is a known trouble spot. The engine/pump harness is about 300-400 bucks, and shouldn't take you very long to change. If it doesn't have the separate harness you'll need the entire chassis harness, it'll run you about $1200-1500 or so (that's what mine cost 4 years ago) and take about a day or so to change out. You can read all about my adventures here: HeavyEquipmentForums Hope this gets you going in the right direction. Any questions please ask and I'll do my best to help as will other people with a lot more knowledge than me. And of course welcome to the forums!!!
Hi Spitzair, Thank you for the quick reply. I had actually read your thread earlier in the day and it seemed to be very similar to our issue. Stopped in at WAJAX yesterday and purchased the full wiring harness. Sounds like it is broken into two separate pieces for easy installation (although i doubt it will be that easy). Anyhow we will give it a shot in the next week here and let you know how it goes. Thanks again. Angus
Hello Spitzair I was able to replace the electrical system on my ex200-2 machine due to help for this forum and it work find for a while but about a few weeks later I heard a clack clack noise coming from the pump area. the next day started the machine the noise became louder and all the hydraulic was dead nothing was moving. I removed the pump and it was finish i replace the parts and reinstall and clean as much metal out of the system as i could but still nothing happens when the control levers are engage. I notice also that the return to the hydraulic tank is very heavy that it spill, when you speed up the engine the return fluid splashes all over the place could this tell me that the pump is working due to the increase in speed of the hydraulic oil as the engine is being rev higher. A spool on the 4 way side was stuck so i dealt with that. I need and idea where to start looking why is it that i cant get nothing to move could it be a valve. thanks in advance man.
Hi daddieboy, I have no idea where to even start... There should be no or very little flow back to the tank with no controls engaged... Somebody will be along soon I'm sure who has some insight... Sorry I can't be of more help.
Thanks man but could you help with with this I don't have a doctor ex but I do have a service manual, now the controllers are giving me a code where both blinks 3 to 4 times together do you know what code is it. Do you have any information on how to interpret the different flashing sequence to the code numbers provided in the manual.
I will look at my manuals when I get home tonight and hopefully have an answer for you.
I can't find anything where it mentions both computers blinking together... If you can tell us what each is blinking exactly, it will help us narrow it down... Watch each computer's flash sequence, if for example it blinks 3 times then pauses, then blinks twice, then pauses longer, that's code 32... If it just blinks steady that's normal... My guess is something in the pump was put together wrong but that's just a guess...
Hey I am loss trying to interpret the blinking sequence so i made a video. May i have you email address so i can get it to you please.
Please send email address so i can send you a video i made of what my controllers are displaying.
Sounds like you still have contamination. Pilot filter is probably plugged. Also, a relief is probably stuck open with your flow to tank
Hello Mike thanks for your input I am an Architect try to get this machine doing something. I recently removed the valve block and clean it out and did removed metal I wash and blow the block with a compressor reinstall but only the bucket moves. I removed the pilot filter and paid attention to see how fast the hydraulic oil move from the outside to the inside of the filter and that is done fast to me so when you you said plugged is that movement you are referring to and also where on the valve bank this relief valve or valves located. As i have mention before as soon as i start the machine oil flows back into the tank really fast so to me i was saying that the valve that suppose to create restriction have a problem but knowing which one blows my mind. I recently ordered a pressure gauge to assist me in my quest. please direct me where and how i should start.
Hello something I notice today in my service manual there are two return lines to the hydraulic tank both have a valve on them do anyone know the function of these valves and secondly why there is no hydraulic returning in the lower pipe that comes from the valve bank.
Hello Guy I have manage to get the machine to move but with some vibration I was thinking air in the system. The heavy return flow is what having me confuse. Help in that area.
Hey guys after cleaning and removing metal from all areas on this ex200-2 machine I finally get to function but still have two areas to deal with 1. I will like to know what could be the cause of that clack clack noise and that pulse coming from the pilot pump. 2. I tried all adjustment to the boom holding valve trying to keep it from not drifting back to the ground so quickly but it doesn't work, what else could i try.
I am looking to replace the wiring harness on my 200 -2 because sometimes when I start it, it continually bounces from full rev to idle. while its doing this, if I move the arm, the machine dies. if anyone has an opinion on this please let me know. ANd where can I find these wiring harnesses?
Hello jd560 I had that problem once and what was causing it to move like that was a bad EC SENSOR on the throttle motor which is located under the hydraulic pump check that area first before going and do that investment you have in mind. All the best man.