I am new to to the forum and just purchased my first excavator for farm use. The machine has several issues such as non of the hydraulics work and the machine will not turn over from turning the key. I can jump the starter and the engine runs good. When I turn the key in the cab, all I hear is a click behind the seat. Would this be a relay problem, a starter solenoid that has gone bad? How can I narrow the problem down? Thanks for any help.
There is a lot of model Kobelco excavator SK200LC. You should mention the serial number of your machine or take a picture of the machine's monitor let we can help you.
Yes, that would probably help. The Serial number is YQU4681. Similar to the first picture. Thanks
Been a while since I worked on a mark 4 but from memory there is a starter safely solenoid which is usually the problem. Take down the belly plate under the engine and as you look from the back of the machine forward it should be mounted on the cross member in front ot the sump. Check have you power here with key in start position. As for the non functional hydraulics take down the belly plate underneath the cab and you will see a manifold with three solenoids bolted to the manifold directly under the cab door. The rear most solenoid should be your dead man solenoid( I think) check if there is power coming to solenoid with safety lever down. If you have power to solenoid push in the little button in the middle of the solenoid and if the hydraulics come live then solenoid is faulty
Fantastic. Thanks for the help. I will work on it this weekend.
I located the battery relay on the frame and next to it is a heater relay. Both go to the starter. I will put a test light to see if I get voltage when the key is turned on the battery relay. I am trying to figure out which of the relays near the CPU is the starter relay.
Hope to be helpful. Good luck.
Thanks for the schematic (it really helps with the red outlining the circuit). I know the fuse was blown that goes to the key SW, but when we replaced the fuse it did not blow or make a difference. I know I am getting current to the starter as I can jump the machine at the starter. There are two relays near the ECU. I think the starter relay has four blades for the plug. I will try to see if I get current out of the relay when the switch is turned. I wish I knew enough to "jump" the connection or the relay to see if that is my problem.
Terminal 30 is fused battery power, terminal 87 is the load ( starter), terminal 86 is from the key or another relay, terminal 85 is ground. If you jump 30 and 87 that will make the starter engage.
Hey Paul. Do you have an image or picture of the terminals? My wiring schematic does not have any numbers. I did call Company Wrench and they wanted $750 for a starter relay. Ouch
This is the type of relay that I was referring to.
That is a big help. I will make a jumper and see if it is the relay. I appreciate the help.
That doesn't necessarily mean that the relay is bad because it starts when you jump those wires. It only means that those wires are still good. You will have to test your other inputs to know if the relay is bad. If all other inputs test good then the relay is bad.
Update: The starter solenoid located under the tractor was bad (thanks Kobelco Ireland - post #4). I replaced the solenoid and it now starts by using the key. However, the machine will not shut off when turning the key in the off position. The electronics in the cab also do not turn off. The problem with the hydraulics was due to the safety switch in the cab located under the locking handle to the left of the seat. The switch was completely removed. I completed the circuit with a bridge wire and will be replacing the switch. All of the hydraulics move painfully slow. Not sure if it is a stuck hydraulic solenoid, the pump or the computer. This is the next problem that I need to figure out.
Glad to hear you got the starter figured out. I’m having the same issue with my sk135 with not shutting off with the key. You may try doing an “AB” adjustment once the “A” adjustment is complete it will show FINISHED with the RPM then it should on some models go into the “B” adjustment which will load test the pump then computer will shut machine down. Once that’s done its complete with the “AB” adjustment.
Has your machine Cummins or mitsubishi engine. Cummins would have a stop solenoid, mitsubishi would use stepper motor to stop engine. Can you read idle rpm and max rpm on your dash. Your machine (mark 4) only has A-adjustment and needs a special cable plugged into the controller to carry out the adjustment
I have a Cummins Engine. Now I reach behind the fuel pump and starve the engine to cut it off. Can you point me in the direction of the "A Adjustment" and do I need a diagnostic computer to do this? My instrument guage is very basic. Also, I did not see a stop solenoid in the parts manual, is this located next to the starter solenoid? Thanks for the help, I am new to excavators!!!
Can you post up a picture of your injection pump. The stop solenoid will be located at injection pump. If you push the buzzer stop button three times the rpm should appear on screen.
According to your machine serial number, It is SK200LC mark IV M/C "minor change". Therefore you should follow the procedure "A" adjustment for M/C machine. I'm sure that after you perform "A" adjustment, then you can turn off the engine by key. Good luck.
The A-adjustment for your machine only sets low and high rpm. Shutting down engine is done with a stop solenoid. Post picture of injection pump and we can point out the stop solenoid
There used to be a "kill cable connected in the back but there is not any cable connections (the joy of purchasing a used machine).
Can you post a wider picture of the pump. Do you know if that's the original engine. I will be honest I never seen anything only a rotary injection in a kobelco powered Cummins. Even the procedure posted above by lachau for your serial number is for a rotary pump set up.
There is no telling if this is the original motor. Someone made the comment that it looks like they took the top part of the machine and dropped it on a different bottom.
I hope I am wrong about the engine hopefully someone can confirm
so picture looks like shut off for cummins 5.9 if am right will need electrical solnoid to turn on/off fuel
Does the motor that handles the governor also increase the throttle (motor speed of the engine)? Probably a stupid question, but the accelerator dial in the cab does not work - at all. I am trying to figure out how to increase the engine speed. I appreciate all the help!!! As you can figure out, this machine needs a lot of sorting out. If I can figure out how to 1) increase engine speed 2) get the hydraulics to speed up with more power and 3) turn off the motor - I will be happy.
years ago did conversion from mtubusi engine to cummins on kobelco log loader was sitting on crane carrier lower
can show pic of out side of injection pump ?
The arm in the above picture moves to the left to increase rpm. When the Dial in the cab is increased the stepper motor should push the above arm to increase the engine rpm. Have you any faults on the monitor in the cab. Can you post pictures of the linkage between injection pump and stepper motor so we can try figure out if it's original or something someone cobbled together. Have you tried disconnecting the throttle linkage and running engine at high rpm to see if hydraulics improve with increased rpm.
OK, that is a big help. So the governor motor does control overall engine speed. I have not tried to increase engine speed to see how the hydraulics worked. The linkage was not attached when I received the machine. It was very hard to turn the shaft coming out of the fuel pump - by hand. I can use a pair of vise grips to turn it (temporarily) to see if it increases the hydraulics. The previous owner stated that engine speed did not help the hydraulics. I do know that when I turn the key before starting, you can hear the stepper (governor) motor turn a small amount. I am positive that the acceleration dial inside the cab does not move the linkage
The shaft should have some spring pressure pushing back against you
You are right. SK200LC mark IV shutting down engine by "ENGINE STOP SOLENOID" and It also has an "ENGINE STOP RELAY". We can find its location in the attached document.
Thanks for the diagrams. My guess is that I have a Lucas pump. Now for the update: I had a Kobelco Dealer stop and look at the machine. They stated that the wiring had to be replaced as there is cuts, wires that have been burned (probably driving through a burn pile) and some that are just deteriorated. They did not want to undertake the challenge - if they did it would cost more than the machine is worth - which I understand. The bad wiring would explain ALOT of the problems with the machine. I have both wiring harnesses (part numbers 2479u1970 and 2479u1780-006). Is there a way to start with the replacement of the harnesses (ie: start at the ignition and work back)? Again, I am very appreciative for the help!!!!
2479U1970 is available from Kobelco it is in Japan the other 2479u1780 is in stock in the states at Texas.
Thanks Dirthog. Those are the two harnesses that I have to put in. The previous owner gave the new harnesses to me when I purchased the machine.
OK had to do those a couple of times just make sure you mark everything well.
OK, I have replaced both main harnesses that go from the cab to the engine and hydraulics. Everything worked (still sluggish) when we left. Today, the engine fires up, but no hydraulics (this machine is driving me nuts). The only item I could think of is the safety switch under the handle which is bypassed (waiting for a replacement switch). It was still bypassed. I have no hydraulic functions at all. The only think different was the switch behind the seat (release or KPSS) was switched when we put the seat back in place. Can anybody give me help on what to look at? I do not have any errors showing on the display. Thanks for the help!!!!
Read post #4 again.
Kobelco Ireland - THANKS you were correct. The safety solenoid would not open. The solenoid has a plug with two wires (connections). When I test for power one terminal in the plug has power the other does not. I am guessing that the solenoid requires two power sources - one to open the valve and one to close. I am not sure which side is being powered (open or close)? Although we changed the two main wire harnesses - the hydraulics worked when we were done, so I am guessing that it is the solenoid. If I energized the side to open the valve, then disconnected the power, would the valve stay open? Right now I had to push the button on the top to make the hydraulics work. THANKS FOR ALL THE HELP!!!!!!!
There should only be one terminal on the plug with power the other is an earth. Current energizes the solenoid to open it and when power is taken away a spring inside the solenoid closes it
On the side that did not have positive power, it did not read positive or negative. I would think the solenoid would get the negative from being screwed into the valve block. If it is supposed to be negative, that may be my problem.
The coil inside the solenoid is isolated from the valve block so needs to be earthed
You were exactly correct. Once I ran a ground to the other side, the hydraulics started working (still slow). I have figured out that people that travel and fix equipment for a living and know what they are doing, avoid "Projects". So I am trying to fix as much as possible (new wiring harness, the machine actually turns on when the key is turned, the starter solenoid does not spin after the motor starts) - all have been fixed. I plan on having the machine as much in normal working order as possible - before asking a professional to look at the hydraulics to see why we are in limp mode. I do have a question, the governor motor has power but does not work. At the motor, we have 24 volts, but at the RPM dial inside the cab, we only have 6 volts. Is this normal? This is the next area that needs to be fixed. I should be receiving the new governor motor this week. Thanks for the help, it has been invaluable!!!!
Don't go poking too many wires to do with the throttle as you could easily damage the controller. Also if key in on and you force the motor to move it will damage the controller. You can check your old motor on the four pin connector between the brown and orange wire you should have 5.7 ohms same on red and yellow wire. Where are you getting the 24 volts
OK, new governor motor came in today. Made sure the battery power was off during installation. Upon start up, if you move the acceleration dial above "low" the motor cycles (high then low RPM). The good news is the new motor works. The bad news is I don't know what is causing it to cycle.
After fitting a new motor you needed to carry out an A-adjustment and make sure throttle is set up in correct position. There is a special harness you need to do it
Kobelco Ireland is spot on: you’ve got to set the parameters. The reason it idles down after increasing rpms is because that’s what it is supposed to do. Please follow his direction.
OK, ordering the special harness today. I read the instructions and it seems straight forward. When I complete the adjustment A, will the machine turn off when I turn the key off to the machine? Right now I have to pull the emergency cable under the seat. Thanks for the help!!!
The A-adjustment on your machine will only set the throttle from minimum to maximum rpm. There should be a stop solenoid on your machine attacked to the stop lever on the injection pump. I can only assume someone removed the stop solenoid at some point and never replaced it
Stop solenoid should be attached to above bolt
Fuel stop solenoid looks something like above
Yes, that is definitely gone. The other challenge I am having is the shaft that comes out of the fuel pump for acceleration has a flat spot on the shaft. The linkage that connects to this shaft must have had a flat sided bolt to connect to this shaft. Well, that bolt is gone. The parts manual, the service manual and the operator's manual do not show the part. I am trying to fabricate a piece using solid square metal and shaving it down to secure the linkage and the fuel pump shaft - not fun.
i This is the bolt - sorry it is not a good picture.
Update; Waiting on the special wire harness. The RPM dial works now and I can increase the RPMs. I don't think the computer adjustment "A" will have an impact on the slow hydraulics. Are there any sugestions on what I should look at to improve the sluggish hydraulics? Thanks for all the help!!!
What's max rpm at the moment. Can you check cycle times and post results up. Check the hydraulic pressures. Sluggish hydraulics could be a number of things low pressure, low flow, pump solenoid or solenoid wiring could be in trouble
Update; I had a very skilled heavy equipment mechanic look at the machine. He stated that it appeared to be the pump based on how the machine was working and that ALL of the hydraulic functions were slow. He recommended a rebuilt pump. So I was speaking with a company that supplies rebuilt pumps and they questioned whether it was a 12 or a 14 tooth gear pump (they go through a third party that supplies the pumps). The part number in the Parts Manual is 24100N8542F1 serial number YQU4681. Can someone confirm that this is the correct pump and whether this is a 12 or 14 tooth gear pump? Thanks for your help!
Géar pump? Your main pump is piston pump k3v112dbt-120r-0e00a. The pilot pump is a gear pump. What tests did he carry out to confirm pump failure, pressures?,cycle times?, etc. the fact he said it APPEARED to be the pump don't me fill me with much confidence. That pump is electronically controlled and faulty electronics or solenoid is usually the cause of slow movement. Did he screw in the adjusters on the pump regulators to see if he could manually increase flow from the pumps
OOPS, my screw up - I think he was questioning how many splines on the shaft. I took my phone and jammed it into the pump area and took pictures. I did find a stamp (not a plate) with what appears to be K3v112 with some letters underneath. The problem I am running into - is that people that travel and work on equipment - show up, tell me what they think and leave. I realize this is a project machine - but I am willing to pay to have it fixed. It just seems like nobody has the time - and they may not. It is making me learn ALOT about the machine which is a good thing. I just don't know much about hydraulics or servo valves. I did go to U tube University to learn how the pump works so I do understand how the pistons ride on a plate that can be adjusted to increase the pressure. I will go back to U tube University and see if I can learn how to adjust the plate to increase or decrease the pressure. On Saturday, I pulled the screen filter in the hydraulic tank after draining the fluid. The screen was a mess (probably never cleaned) and my hydraulic fluid was the color of coffee with cream added to it (moisture from sitting too long?) I cleaned the filter and replaced all the hydraulic fluid with new fluid. The screen did have metal shavings but they were steel as they stuck to a magnet but no brass shavings from the pump. The cleaned filter and new fluid did not make a difference. Is there a high pressure test port to test the pump pressure? I did purchase a pressure gauge that goes up to 5000 psi. The last technician disconnected one of the wires going to a pressure valve (bottom left hand side of the pump) and it did not make a difference. He stated that my problem was not electrical - but he did not do any testing accept for removing the wire from the valve to see if it would make a difference. I guess my next step would be to test the high pressure side of the pump with a gauge and learn how to adjust the pump plate.
Sounds like a part cannon to me.
so he disconnected one solenoid and condemned hydraulic pump. We need to know the pump pressures because weather or not there is pressure will determine what direction you go with the repair. Post a few pictures of the pump and we can point out the test ports
Yes, you are correct. Disconnected one valve (high pressure valve?) and that was it. I am going to have to figure out (myself) how to test the high pressure side of the pump and how to adjust the pressure plate.
The plates you are talking about are called swash plates, changing the angle of them changes flow rate not the pressure of the pump, pressure is set be adjusting the main relief valve which is located on the main control valve(valve chest). Also what you call the high pressure valve is the pump solenoid. Post pictures of the pump and we will point out the different parts and where to attach your gauges etc.
Here are pictures of side of the pump
Another pic
One last one
Update: Brought the pump to get rebuilt (company specializes rebuilding pumps and has been doing it for 50 years). They called and stated the pump has normal wear (swash plate and piston edges) and can use a rebuild. However, based on what they saw, the pump is not the cause for the slow hydraulics. Having an experienced person pull the two main valves / solenoids.
Check your signal wire from your alternator if it does not switch from a power to a ground the machine will not shut down with the key. This can also cause issues with not starting with the key as it thinks the engine is already running
Did you check your pilot pressure that can cause slow hydraulics. Are all functions slow or just some of them? Does the machine track normally
Yes, the pilot pressure was at 800 PSI, so I think we are good there. My plan is to put the rebuilt pump back in and then try to do pressure readings leaving the pump to try to see where the pressure drops. Not sure if this is the best way to track it down, but I am running out of options? Thanks!!
Check to see if you have full main pump pressure with system held over relief. If you do have full pressure, you have a low flow problem. Are all functions slow or just some. How slow is the machine can you post up cycle time results
If the machine has set for a long time I've seen the main reliefs rust up.
All functions are slow (boom, bucket, travel and swing). Travels about 1/2 mile an hour if this gives you and idea. The system is a dual main valve system (?). A mechanic (mechanic #3) pulled the valves and stated that he did not see anything obviously screwed up. His plan is to put the rebuilt pump back in, do a high pressure reading at the pump then do pressure readings at different points as you leave the pump to see what point the pressure drops. Pump will be ready for pickup this Friday and they are replacing the valve on the pump.
Pressure is power and speed is flow. You will get good pressure readings if the pump is good and the relief valve is good and still have slow functions. If the pump isn't stroking up when a function is activated then you will get slow functions. I'm not sure how your pump flow is regulated. You will need that information from one of the other guys on here to troubleshoot that. Right now I believe that your pumps are not stroking up and your pumps don't really know that you are calling on a function.
Bigwrench - thank you that explains a lot. I did replace the governor motor and did not have any luck with the "Program A" to get the CPU to talk to the gov motor. I am able to increase the RPMs using the dial in the cab. Can I push the "release:" lever to bypass the cpu? Even if I have the RPMs high, everything is still sluggish. The pump rebuilding company did not put the original pump on the dyno when it was brought in. They just told me that "the pump had normal wear and tear but nothing out of the ordinary". They are putting the rebuilt pump on the dyno tomorrow and will provide a readout when I pick it up.
If you are using the hydraulic override that is why your functions are slow the machine controller is what controls your pump psv's. That is for emergency to get the machine to a safe location. What happens when you try to do the A adjustment, does it fail or just not start one
The first time it failed - symbol flashed a couple of times and stopped. Afterwards it will not start the process. The special plug has three connectors. I only used the two connectors that connected to the one wire coming out of the cpu. (disconnect the plug, plug the special wire harness into one end, then connect the other end of the special wire harness to the other end of the cpu wire). The third connector does not connect to anything. Is that correct? Up to this point, I have kept the machine in KSS and have not used the override - but was considering switching. Thanks for the information above, I will keep it in KSS mode. Thanks for the help.
Are you talking about a harness with a push button or harness for programming. It's been a long time but if I remember right you have to start the process with no error codes then hit the button to move through the steps
Push button. The instructions are detailed from the service manual. When you replace the governor motor, it will cycle and gives you an error. My understanding is that you follow Program A, and when you get a fail, you start again. Replacing the hydraulic pump tomorrow.
Did you adjust the linkage first
Did you adjust the linkage first
No, which may be the problem. Putting the hyd pump back on this morning. Then, I will take the linkage off (per the instructions and try again. Thanks.
Update; The rebuilt pump was put on today. The valve body located between the pump and the hydraulic tank had two valves stuck. They were cleaned and put back. Now the swivel, boom lifting, boom extension and right side track work at normal speed. The left track and the bucket remain slow.
If it's the valve I think you are talking about that should be your independent travel valve, which would separate your pumps one to work travel and one to work machine. There where allot of issues with these failing, most machines I've worked on had this valve capped off. Did you ever get your monitor working so we could check Millivolt readings at the psv's. This would help you determine if it's electrical or hydraulic issue.
Working on it tonight. Mechanic (#4) is very knowledgeable as he works for a large equipment company doing repairs. He thinks it is servo / valve related. The valves we have taken out so far, had sat for along time, were sticking and had a small amount of surface rust. We are taken them out, cleaning them and making sure they move freely. I still have to do the Adjustment A - which is a challenge as the screen in the cab is really hard to read. The instructions to do the Adj A state to disconnect the one wire and connect it to the push button. But the push button has three wires. I don't know why push button harness would have three wires when you only use the two.
It's used for multiple machines I belive the third was for large machines. You can also do the procedure without the button it's just more of a pain because every time you need to move to the next step you have to reach back and touch the two wires together. There should be a procedure in the manual for this
The first ones I would check would be the p1/p2 psvs next would be the p1/p2 unloaders or bypass cut as they call it. Simply swap p1 for p2 and see if the problem follows. If this does not change anything I would swap p1/p2 negaconn pressure sensors, then p1/p2 high pressure sensors. You can read all of these in the monitor that is why I asked. Is you monitor screen faded or did the back light go out. If the plastic is fade you can take that monitor apart and remove the cover so you can read it. If the back light went out it helps to shine a flash light into the screen
Thanks Kyle! I will try switching the items above and see what happens. In requards to the "Kobelco Special Wire Harness" needed to do Adjustment A - if I knew it was just two wires and a momentary switch, I would have saved the $250 and made my own. The back light is dim on the monitor (lens is ok). I need to figure out how easy it is to replace the internal light before spending $500. Thanks for the help, I will let you know how it goes.
Your machine is a mark 4 it does not have negative control sensors, high pressure sensor etc.
Have you checked main relief valve? If every function is " low power" or slow this would be the first thing I would check.
Ok, today I got the CPU to sync with the new gov motor. I still cannot figure out what is causing both the bucket and the left track to be slow (everything else is good). Below is the valve body next to the hydraulic tank that had two valves stuck. It was cleaned and helped alot. The second is the valve body that we cleaned that goes directly to the bucket - it did not make a difference. The last is the rebuilt hydraulic pump. Can somebody give me some help on what to check next - pictures would definitely help. THANKS
Swap your p1/p2 hoses and see if the problem follows
After reading all 5 pages.....Kobelco Ireland is the MAN! I have the same exact Kobelco and am having a helluva time with it. I will try all of the great information in here, but mine, started for 3 seconds, and then just shut down with a huge black cloud. I've had a few look at it and none had half the info I learned in here! So after a new fuel filter, new batteries and a million suggestions....I'm taking over! The thing turns over just fine, it just won't "fire", which to me sounds like the shutoff solenoid, or a relay, or even a fuse....so I'm going to get dirty! I can only hope that "The Man" still participates with the site as I would love his guidance! (Not saying there may not be another Kobelco Einstein in here, which I will absolutely welcome his....or her help!)
Yes this forum is great. When I first purchased the excavator (my first piece of heavy equipment) - I received a VERY QUICK education on having it worked on. The first call was to the Kobelco Authorized dealer and scheduled an appointment to have the machine worked on. Three days later, a kid right out of high school jumps out of his service truck, looks at the excavator and says "this is a project". He jumps back into his truck and leaves. He never touched a tool or even started the machine. It turns out, the kid lived five miles away in Hubert NC, and I was charged mileage (from Smithfield NC - 180 miles), labor, and a service call that resulted in $1,750. Next was a gentleman that worked for CAT. He cleaned the hydraulic spools, charged me a TON for hydraulic fluid and did not fix the machine - another $1,000 down the drain. Next was a young man that worked on Kobelco machines for a rental company. Scratched his head and started the machine and left - $500. Next was an older gentleman that owned his own business working on heavy equipment. He stated that I needed to have the hydraulic pump rebuilt. He did not have the time to work on it. He did not put any gauges on the pump - just guessed. Well $6,500 later the pump was rebuilt (me and a friend took it off and I brought it to SC to have it rebuilt). Still did not make a difference. Next was a company out of Morehead City. They sent a young man that worked a week on the machine (once again cleaned the spools). He could not fix it. His boss (the owner of the company) showed up and had the machine fixed in two hours. Turns out the control pilot lines were switched around. The gentleman stated that the machine was probably repossessed and the owner switched the lines around for spite. I dreaded receiving the bill, but when I did, it was only $2,800 (including the week the employee spent working on the machine). Nine months later it was near Christmas, I called his secretary and asked what the owner liked to drink. She stated Captain Morgans Black. I bought him a 1/2 gallon. When I gave it to the owner - he said "you didn't have to do this". I told him "YES I DID" as he was number 5 to work on the machine and finally fixed it. I figured out that "I better get to know how to work on this machine or life is going to suck depending on other people". This site is a life saver.
This is a great thread...amazing input by all. Amazing amount of knowledge and experience being shared.
can you tell me what is the pin needed to be shorted ? please
behind the seat by the controller is a plastic 1 spade connector you need to connect and disconnect this connector to move through the adjustment.