Kobelco hydraulic excavators

[SK80CS]

SK80CS strange hydraulic problem

Hi Adam,
I have an SK80CS LF01-000540. I have a strange hydraulic problem. Left track is slow and will stop, Right side normal, Arm in is slow, Arm out normal, bucket close is slow, bucket open is normal. left boom swing is slow, right boom swing is normal. Slew appears normal, dozer appears normal, boom appears normal. If you engage the right track while using any of the slow functions, they speed up. We swapped the two main pressure lines on the pump and nothing changed.

Any ideas what could be happening ???

Arm out will also stall the engine, but I believe that's a different problem ...

Best regards,
Mick

 

[MR. KOBELCO]

Hi Adam,
I have an SK80CS LF01-000540. I have a strange hydraulic problem. Left track is slow and will stop, Right side normal, Arm in is slow, Arm out normal, bucket close is slow, bucket open is normal. left boom swing is slow, right boom swing is normal. Slew appears normal, dozer appears normal, boom appears normal. If you engage the right track while using any of the slow functions, they speed up. We swapped the two main pressure lines on the pump and nothing changed.

Any ideas what could be happening ???

Arm out will also stall the engine, but I believe that's a different problem ...

Best regards,
Mick

hi mick,

obviously be sure to swap the hoses back to the way it was.
questions;
- do you have the shop manual to refer to?
- does your machine have factory auxiliary hydr plumbing, if so are you using the plumbing for an attachment ?
ie.; hydraulic thumb or such...
- have you taken hydr pressure readings from pressure test ports on the pumps?
- what is your engine rpm ? at lo-idle and hi-idle
- i would ask that you e-mail me your info along with the data that i ask for below, so that i can respond, my e-mail is " hf_hydraulics@hotmail.com
- the test ports on the pumps are a 1/4" jis bspp thread - that is bspp with an o-ring
gauges 2 X 6,000 psi
1 x 1,000 psi
with 6000 psi gauges on each main pump
boom up over relief and record
with travel sprockets in the back,
then stall tracks going forward by pin in sprocket jams against the frame and stall both together and record
then stall in the reverse direction too
what is even helpful since your gauges are in is to stall each circuit and record also
ie;
arm out
arm in
bucket dig
bucket dump
swing right and then left (teeth locked in ground)
dozer is usually a seperate gear pump
pilot pressure is also needed
etc...
adam

 

[shinigamix2x]

Good day to you all, here's my small problem:

SK210LC Dynamic Acera ~ YQ08

Machine can’t left-track and swing at the same time, When the travel-left lever is fully or half-way activated, the left track motor works fine, but when we engage the swing lever, the pump stalls, makes a loud noise like when you’re doing “boom over-relief”, then the left track motor slows down a lot.
Same thing applies as to when you’re swinging either left or right, it works fine but once you activate the travel left lever while swinging, same thing happens, the swing slows down a lot and the pump makes that loud growling noise.

I’m quite new to these things, but thanks to Adam I was able to do the following checks.
• Checked solenoids on solenoid valve block ~ all solenoids are ok
• Checked Pressure Switches on pressure sensor block ~ all pressure sensors are ok
• Checked Independent Travel Solenoids ~ Solenoids are ok
• Checked pressure readings on Mechatronic Screen ~ operated machine and recorded all pressure readings. All Pressure Reading Are OK
• Also not really relevant to this, but for testing purposes we’ve reset the stepping motor adjustments (A&B adjustment, Also reset the voltages to the solenoids using the mechatronics)
• Engine RPM is ok
• Pump 1 and Pump 2 Pressures are ok

Everything else on the machine is working fine, Dig, Dump, Swing Left, Swing Right, Boom Up/Down, and Stick In/Out, Travel right, left etc. I'm supposed to check the port relief valves after but the machine went out to work that same day and didn't get the time since. But then again i'm not sure which relief valves to check.

Thank you all for your time, please share some ideas.

 

[Porter]

A friend recently had the swing motor stolen from a K905 in Eastern CT. He finally found a reman replacement but if you heard of anyone selling this part *used* in Eastern CT I would appreciate it.

 

[StumpyWally]

hi tom,

the way i normally check for internal oil bypass on a hydr cyl is quite simple.
start the machine and operate the cylinder in order to extend out the rod right to the end of its stroke.
shut-off machine, relieve the pressure off the hyd tank
carefully undo the hyd hose that connects to the rod end of the cylinder,
place this hose from the rod end into a 5 gal pail,
cap off the machine - open end of hyd line/tube,
start the machine and operate it as to extend the rod once again, same as before,
if the oil exiting the hose into the pail is more than a teaspoon
then the cylinder will require overhauling.

sometimes hyd thumbs do drift over time. some drift is normal.
if you tend not to use the hyd thumb too often we have initiated a mechanical lock unto the arm
so when the hyd thumb is parked against the arm it can be locked so you do not have to keep intermittently having to repark it
over and over thru a job.

cheers!
adam

Adam:
Thanks for the advice on checking for oil bypass on hydraulic cylinder. But one question...why do I have to "cap off the machine - open end of hyd line/tube" when I try to extend the rod, won't this machine end be under no pressure (unless the control valve leaks a little)??

Also, regarding the drifting thumb, what do you mean "we have initiated a mechanical lock unto the arm"?? Do you mean that Kobelco now builds such a lock into their new machines? Or that you have added such a lock in the past? Any ideas on how to add one to my machine??

Finally, can you help me obtain a shop or repair manual for my excavator for future reference?? It is a 2005 New Holland EH 80 (Kobelco), s/n or pin # N5TA18019, Machine # LF04-02072, Isuzu diesel engine # CC4JG1-272608 with a build date of Feb 9, 2005, 600mm wide steel tracks, 2.07 meter arm, 3.72 meter boom. I have the original packing list from Kobelco to CNH America.
Tom

 

[MR. KOBELCO]

Good day to you all, here's my small problem:

SK210LC Dynamic Acera ~ YQ08

Machine can’t left-track and swing at the same time, When the travel-left lever is fully or half-way activated, the left track motor works fine, but when we engage the swing lever, the pump stalls, makes a loud noise like when you’re doing “boom over-relief”, then the left track motor slows down a lot.
Same thing applies as to when you’re swinging either left or right, it works fine but once you activate the travel left lever while swinging, same thing happens, the swing slows down a lot and the pump makes that loud growling noise.

I’m quite new to these things, but thanks to Adam I was able to do the following checks.
• Checked solenoids on solenoid valve block ~ all solenoids are ok
• Checked Pressure Switches on pressure sensor block ~ all pressure sensors are ok
• Checked Independent Travel Solenoids ~ Solenoids are ok
• Checked pressure readings on Mechatronic Screen ~ operated machine and recorded all pressure readings. All Pressure Reading Are OK
• Also not really relevant to this, but for testing purposes we’ve reset the stepping motor adjustments (A&B adjustment, Also reset the voltages to the solenoids using the mechatronics)
• Engine RPM is ok
• Pump 1 and Pump 2 Pressures are ok

Everything else on the machine is working fine, Dig, Dump, Swing Left, Swing Right, Boom Up/Down, and Stick In/Out, Travel right, left etc. I'm supposed to check the port relief valves after but the machine went out to work that same day and didn't get the time since. But then again i'm not sure which relief valves to check.

Thank you all for your time, please share some ideas.

hi,
please be very aware...
all the propovalve solenoids do show and display a pressure value
in the monitor but,...
this is only a calculated pressure...you must tee into the pilot line at the particular spool cap or port that the signal ends
in order to confirm 100% that you are indeed getting the pressure matching what the display screen says should be there
this is based upon the mA signal.
also, i had just fixed one machine yesterday
the screens all looked fine, but when i teed in a pressure gauge it always read zero.
end result i came to was that even though the mA signal was present the c-1 mechatro-controller was not able to provide it the necessary voltage behind the mA
to shift the psv solenoid valve. i replaced the c-1 mechatro-controller and regained the psv signal pressure.
machine is now performing 100%.
cheers!
adam

 

[MR. KOBELCO]

Adam:
Thanks for the advice on checking for oil bypass on hydraulic cylinder. But one question...why do I have to "cap off the machine - open end of hyd line/tube" when I try to extend the rod, won't this machine end be under no pressure (unless the control valve leaks a little)??

Also, regarding the drifting thumb, what do you mean "we have initiated a mechanical lock unto the arm"?? Do you mean that Kobelco now builds such a lock into their new machines? Or that you have added such a lock in the past? Any ideas on how to add one to my machine??

Finally, can you help me obtain a shop or repair manual for my excavator for future reference?? It is a 2005 New Holland EH 80 (Kobelco), s/n or pin # N5TA18019, Machine # LF04-02072, Isuzu diesel engine # CC4JG1-272608 with a build date of Feb 9, 2005, 600mm wide steel tracks, 2.07 meter arm, 3.72 meter boom. I have the original packing list from Kobelco to CNH America.
Tom

hi tom,
if you do not cap off the machine you'll lose alot of oil.
usually when the machine is running each circuit not being functioned will register 200 or so psi.
you will empty your tank!

on the other note please e-mail me...so i can return info
my e-mail: hf_hydraulics@hotmail.com
cheers!
adam

 

[MR. KOBELCO]

2003 SK200FR-LC with erratic(jerky) swing both directions,worst if multifuntioned

hey again,
just a reminder i need you to e-mail me all your info.
i'll need to set you up as so i can send info
e-mail: hf_hydraulics@hotmail.com
cheers
adam

 

[shinigamix2x]

Thank you Adam, will work on that as soon as the excavator returns to the garage,
On another different note,
We're doing a restoration on a SK330LC Dynamic Acera, (YC06). Right now i'm getting no where looking for the connectors for the solenoids and pressure sensors on the Hydraulic Pump. If you can supply these for me i would greatly appreciate it. Though i know it will take some time to ship from Canada to the Caribbean but i don't mind that at all. Also the connectors for the Stepper motor as well. Been looking around, liaised with a few kobelco dealers but no luck.
Thank you for your time.
Best regards.

 

[IH560JL]

Anyone have info on kobelco sk50ur with yanmar 3tn100 engine, looking to buy, told engine has a "tick" have not heard it run yet. I know it was not setup for us market. All working is in japeneze symbols. Where can i get a free english manual? Thks jim 8156260328

 

[MR. KOBELCO]

Anyone have info on kobelco sk50ur with yanmar 3tn100 engine, looking to buy, told engine has a "tick" have not heard it run yet. I know it was not setup for us market. All working is in japeneze symbols. Where can i get a free english manual? Thks jim 8156260328

hi,
since this machine is grey market i would advise run the opposite way.
unless you purchase the following 2 manuals if you have any questions on the machine or need parts without them you'd be sol.
the only manuals available to purchase will be from Farmers Equipment in the usa.
an operators and parts catalogues.
the repair or service manuals are not obtainable at all.
cheers!
adam

 

[dattuan]

Dear all !
I have a Kobleco SK330-6, now travel left is fine but travel right is slow and bucket dump and digging are slow, when I work other functions ( boom up -down, arm in-out) , travel right is fine. Can U help me !..Thanks very much .

 

[MR. KOBELCO]

Dear all !
I have a Kobleco SK330-6, now travel left is fine but travel right is slow and bucket dump and digging are slow, when I work other functions ( boom up -down, arm in-out) , travel right is fine. Can U help me !..Thanks very much .

hi dattuan,

i require your serial number - YC06- or YC07-
e-mail this to me at " hf_hydraulics@hotmail.com "
i'll see what i can offer for you to check
cheers!
adam

 

[muddog]

Muddog,
I'll send you a pm about our brand of slewing rings for your machine.
Bolts for the upper frame come out, bolts for lower frame. Disconnect hoses and undeck. It's a chore. If you don't have a service manual I am sure Adam can help you with detailed steps.

Thanks for the info, I will contact them next week. I've been told there is a video someone posted of the slewing ring replacement in the field. I have looked, but have not found it. Do you have any info on this? If anyone knows where to locate it, I would deeply apperciate it.
Thanks,
Muddog

 

[muddog]

info

yes,
finaldrive is correct, please e-mail me your info with a fax # to " hf_hydraulics@hotmail.com "
cheers!
adam

Hi Adam, Hope you have enjoyed Your time off. Finally got the fax to work and also recieved the copy in the mail. Non to determine the best way to block and jack the machine up to make the repair it. Have a Very Happy New Year.

Thanks for the info,
Muddog

 

[domsant17]

I have a sk75ur that is having fuel problems. It seems as if the machine unprimes itself every time I shut it down. No visible fuel leaks. the fuel all seems to bleed back to the tank. I hope I am using this forum properly. This is my first time.

I agree with mr. Kobelco. all you have to do is to check/change the two check valves found inside the fuel feed pump. It's the inlet and outlet check valves, sometimes only the tensioner spring is the culprit. you can buy the set of check valves with the spring.

 

[LACHAU]

Dear all !
I have a Kobleco SK330-6, now travel left is fine but travel right is slow and bucket dump and digging are slow, when I work other functions ( boom up -down, arm in-out) , travel right is fine. Can U help me !..Thanks very much .

Dear Mr.DATTUAN,

Tôi nghĩ một vế bơm của bạn bị lỗi rồi (vế bơm dành cho chân bên phải. Bơm số 1). Bơm này đồng thời cũng dành riêng cho Bucket.

Khi bạn thao tác BOOM hoặc ARM, hai bơm một và hai sẽ hòa với nhau. Nên lúc ấy chân phải lại chạy tốt (lưu ý van TRAVEL PRIORITY trong van phân phối).

Bạn xem trên màn hình có báo lỗi gì không?

 

[CM1995]

Lachau, we are going to need your last post translated to English please. In the future please post in English, as it is the Official language of Heavy Equipment Forums.

Thank you,
CM

 

[joshua23]

Hello, I'm having a problem with our Kobelco sk200lc mark IV excavator. When i go out to start it up it cranks and starts normal but once it starts its idle is very low and it will not throttle up. It just started randomly doing this and im wondering if it is a problem with the stepping motor. Im not getting any msgs. or codes on the screen. After it sits and idles rough for a bit it will gradually idle up on its own then after that it all works normally. Any suggestions? Thanks in advance! Josh

 

[LACHAU]

Dear Mr.DATTUAN,

As Mr.KOBELCO said; you should tell the serial number of your machine.
I think the No.1 main pump has gotten trouble. This main pump is supplied pressurized oil for Bucket and Right travel.

While you operated BOOM or ARM, the two main pump are merged so that the right travel has been OK. (It through the TRAVEL PRIORITY valve at Control valve)

How is the monitor display? What error code ??