I have a Kobelco SK200LC Mark IV Serial# YQU3989. When I put the machine under strain, the hydraulic system will kill the engine. I've had the engine checked out and there doesn't seem to be anything wrong with it. In researching this problem, it seems the hydraulic regulators(compensators?) on the pump should kick in and relieve the pressure in that situation instead of dragging down the engine. If they somehow are adjusted too high, the main relief valve should kick in. At least that's my understanding from my research. I purchased a shop manual that cost a pretty penny and it doesn't show me how to adjust those valves. Is there some documentation that shows a step-by-step procedure for doing so? Thanks in advance for any help.
Unless someone adjusted the regulators before, you should never have to adjust them. If engine power is correct then the pump solenoid should stop the hydraulics from overloading the engine. The pump solenoid should destroke the pumps and allow the engine to run at full rpm
I had a diesel guy check the engine and he says it's putting out what it needs to. So if the pump solenoid goes bad, that's how the engine gets overloaded? How do I check that? Also, is there a set of solenoids? The problem is worse on the boom out and in, but it will stop the engine on the bucket dig.
It does not pull down the pressure, but reduces the pump's flow, thereby reducing the load power (which is the pump's power consumption) to match the engine power. That adjustment is done by the regulator. The regulator works by two parts: electrical and mechanical. Even if the electrical part works well but the mechanical part is stuck, the regulator will not be able to adjust the pump power to match the engine power, then the engine will still be overloaded. I suggest you try to adjust the regulator to see if it still works. Try loosening the 2 screws to see if there is any change? I also have attached a file for your reference about the regulator of SK200LC mark IV machine
Breauxlg did you get the issue resolved. I’m having a similar problem with a Doosan solar 225lc-v. Did you have the regulators adjusted?
LACHAU, thanks so much. I'm going to try that just as soon as I can get back to the machine.
I'm going to try that this evening if I can get back to the machine. I'll post the results.
I had the same problem with a Kobelco SK200. The engine ran fine, but the RPMs were too low and it would put a strain on the motor under a heavy load.
Okay, sorry it took so long to get back to you. I tried adjusting the regulators and was able to make the bucket work the way it's supposed to. It doesn't kill the engine, simply loses power. The stick control will still kill the engine, however and trying to use multiple functions - stick, bucket, lift bogs it down severely. I did change the fuel filters, but I was told by my local Kobelco service center to make sure the screen filter going into the injector primer pump is not clogged. That will be my next step since the Kobelco service folks would not be able to get to me for a bit. I'll post results here when I try it. Thanks again for all of your replies and input.
Since my last post, i had my fuel and hydraulic pump pressures checked by a Doosan Tech and everything is in spec. He recommended changing the proportional valve on the hydraulic pump. He believes the proportional valve is not working correctly and sending to much oil to the front pump causing an engine overload situation. So I've got the proportional valve and I am swapping out tomorrow. Ill post results if that cures it next time I'm out with the excavator. Fingers crossed lol.
I wish my pump would stall the motor............ my pump is that tired it can’t dig water does that machine have the “A” mode function? If so, try running on that mode. It makes the pump and motor work together better without so much loading up of the engine. A= auto M= manual B= breaker They are just work modes
Okay, was able to adjust most of the functions to get decent functionality, but the adjustment for the left/right travel felt very different from the other three. After breaking the lock nut, it turned very easily by hand. The local Kobelco service guy said if he sent out a mechanic, they would just pull the pump and send it to a local hydraulics shop, so my son-in-law and I pulled the pump and brought it in. The cylinder on that housing was scarred among other problems and their list of parts without the housing was $2,500 and they said the lead time on the housing was 20 weeks. I found a housing that was in stock but was $1,500. So I would have $4,000 in parts plus labor to fix the pump. I ordered a new aftermarket pump with a one year warranty from Conequip for $5,900 delivered. It's coming in Wednesday and I'll let y'all know what happens after we put it back in. The pump did not have any trash in it. We pumped out and drained the hydraulic tank and check all the filters and found no trash, so I guess the scarring happened at some point and they just cleaned up the fluid after that.
Como te fue??
L