Kobelco hydraulic excavators

[Kobe130]

Kobe130 Swing Problem.

Thanks GrandKobelco and Adam. I did discover a fitting with stripped threads (previous mechanic) where the fitting appeared to sit normally but as soon as I turned a hose fitting on the end it basically fell out of the swing control motor valve block. In the process of repairing it now I presume it was leaking hydraulic resulting in loss of signal to the pump regulator. Many thanks for your help.

 

[MR. KOBELCO]

Adam, I believe that was high idle, hydrolics warmed up, and safty lock disengaged ( ready to work )
Also my stick cylinder, the one on top of the boom, is leaking oil externally from the seal. I have had it resealed twice. First time lasted about six months second time only lasted about a month. I don't EVER "chop" with the machine but I do run a Tramac 900 hammer sometimes. are some seal kits better than others or should I look for another shop to do my cylinder repairs ??
And yes it is an Isuzu engine.
Thank you for shareing your knowledge and insights !! If you ever make it to centrial Texas I'll buy you a steak dinner

hi,
oem seals are good even better than aftermarket, but we do send off our hyd cyls to get overhauled at a reputable hyd cyl shop.
he uses aftermarket seals, and we have had no come backs.
by the way,
in regards to B10 pilot sensor,
if it is indeed providing an input signal to the c-1 cpu then the computer will think you are using your travels when you are also running the upper machine functions.
when you operate the lower travels and upper at the same time the cpu basically divides the hyd pump flows as so you are one pump for upper (P1) and the other runs the lower (P2).
i would suggest that this sensor if problem is replaced to correct machine functions.
cheers
adam

 

[gregor1978]

Hello Mr. Kobelco,

I still did not diagnose the couse of problem.

One hose going on to the valve P2 is flexible and You can see when pressure raise there.
I did not have stalling pin or simmmilar so I did not measure travel relief.

I found one old block and I took out travel relief and I change it with the one on right travel block ( because it concern bucket and boom). There was no change.
I took out also main relief and replace it with one from working exavator- there was very slight difference - bucket very slowly closed. I test everythink with bucket 1,2 m3 ( largest).
With original relief valve could not close in wet mountain of soil. I heard pump regulating and relief opening but the bucket could not close. So I gues all the flow goes out over relief.


I noticed that original relief is not like it should be from catalog but it is like on SK200 sn YNU7922. It has o-ring and back up ring. I noticed that this valve Was leaking a little bit because some part of back up ring ( where it comes together) was missing and o ring there was also a little deformated. Also this time when reliefing wheezing was heared- I think that oring and back up ring on relief. But I think this leaking could not open main popet? There must be a leak on cone or between popet and housing if oil is going from spring chamber of popet to tank?
Could constant leaking on oring and back upt ring cause housing deformation?
I also put on a little bigger oring without back up ring and wheezing was canceled but bucked still could not close. If thinks ware o.k. bucket should pull machine farward.

But if I go to the last time measurment of pump going on valve block on P2 conection ( measurment was the same when I changed the pump lines).
When the boom is lifted to the end and comand for lifting is still there the flow reading for P2 was 60 l/min. If comand for lifting is relised and pressed again than flow on P2 goes only to 26 l/min.
Why regultaor once close the pump on 60 and once on 26 l/min?
Also once litfting wit flow on P2 of 60 l/min and second no lifting with 66l/min.

I also turn in the small screw for flow on regulator. When this was done machine was fater with no load and the engine felt it very hard. When put under load thinks ware the same - no power. Should I put in larger screw on regulator to regulate pump to min a little slower? I think not.

I do not have any idea more...

 

[MR. KOBELCO]

Hello Mr. Kobelco,

I still did not diagnose the couse of problem.

One hose going on to the valve P2 is flexible and You can see when pressure raise there.
I did not have stalling pin or simmmilar so I did not measure travel relief.

I found one old block and I took out travel relief and I change it with the one on right travel block ( because it concern bucket and boom). There was no change.
I took out also main relief and replace it with one from working exavator- there was very slight difference - bucket very slowly closed. I test everythink with bucket 1,2 m3 ( largest).
With original relief valve could not close in wet mountain of soil. I heard pump regulating and relief opening but the bucket could not close. So I gues all the flow goes out over relief.


I noticed that original relief is not like it should be from catalog but it is like on SK200 sn YNU7922. It has o-ring and back up ring. I noticed that this valve Was leaking a little bit because some part of back up ring ( where it comes together) was missing and o ring there was also a little deformated. Also this time when reliefing wheezing was heared- I think that oring and back up ring on relief. But I think this leaking could not open main popet? There must be a leak on cone or between popet and housing if oil is going from spring chamber of popet to tank?
Could constant leaking on oring and back upt ring cause housing deformation?
I also put on a little bigger oring without back up ring and wheezing was canceled but bucked still could not close. If thinks ware o.k. bucket should pull machine farward.

But if I go to the last time measurment of pump going on valve block on P2 conection ( measurment was the same when I changed the pump lines).
When the boom is lifted to the end and comand for lifting is still there the flow reading for P2 was 60 l/min. If comand for lifting is relised and pressed again than flow on P2 goes only to 26 l/min.
Why regultaor once close the pump on 60 and once on 26 l/min?
Also once litfting wit flow on P2 of 60 l/min and second no lifting with 66l/min.

I also turn in the small screw for flow on regulator. When this was done machine was fater with no load and the engine felt it very hard. When put under load thinks ware the same - no power. Should I put in larger screw on regulator to regulate pump to min a little slower? I think not.

I do not have any idea more...

hi gregor,
first thing, i agree do NOT attempt to adjust any of the hyd pump adjustment screws.
i have a few questions...
1) when accessing the serviceman's maint screens in cab display (dash), are you able to read an engine rpm "comp value" and when the engine is running does it read the rpm sensor "measure value" ?
2) are you able to tee into both the "pi1"/"pi2" pilot hoses with 1,000 psi hyd prs gauges ?
as well as get into the hyd pressure test port located on the pf solenoid manifold block itself too ?
3) i ask to record and advise the pi1/pi2 nega-con hyd pressures in neutral - both at engine lo-idle and then both at hi-idle "H" mode
4) i ask to record the pf solenoid proportional hyd prs at hi-idle "H" mode, and when you operate the machine does the c-1 computer vary this hyd pressure during movements ?
5) i ask that you then pay very close attention when,
- have arm all the way in to cab
- then moving the stick (arm) out away from cab - quick full stroke of joystick control lever - during engine hi-idle "H" mode
- monitor the pf solenoid hyd pressure gauge and also in the cab dash the engine rpm drop during this movement
6) please then report this hard data for review
thanks
adam

 

[Oliver]

Hello, Mr. Kobelco

We have a SK45 Kobelco serial# PY03114. We have tried to find some information on the year model, and if in fact it is a SK45 I have ask Kobelco, They cannot locate the serial number. I am sure the machine was Imported. Will you help me?

Thank you
Oliver

 

[Iron Mechanical]

I finally got a S/N kobelko sk350lc yc08u1942 with engine abjo8etm the engine has a miss is there any way to isolate the injectors electronicly and can I pull fault codes through the dash. Where can I get a manual for this model I have found online manuals for all the older machines but nothing for the tier 3 machines. Thanks Jason

 

[kp100]

SK 60 1995 LE-17572. Well after 100 hours of on again off again service screen showing the wrench symbol it is back on for good. Worked fine all last week, run every day. Sat over the weekend and now have nothing but the wrench. After 2 days I guess it is not coming back on. Found a very recent Cluster controller but am hesitate at buying a third one. Still no clue as to why they fail or even if that is the problem. Should I be changing the wiring harness before ruining a third controller? How much is a new harness installed???
In too deep now.

 

[MR. KOBELCO]

Hello, Mr. Kobelco

We have a SK45 Kobelco serial# PY03114. We have tried to find some information on the year model, and if in fact it is a SK45 I have ask Kobelco, They cannot locate the serial number. I am sure the machine was Imported. Will you help me?

Thank you
Oliver

hi Oliver,
please e-mail me direct @ hf_hydraulics@hotmail.com
i'll see what i can muster up and send you.
sorry for delayed response.
adam

 

[MR. KOBELCO]

I finally got a S/N kobelko sk350lc yc08u1942 with engine abjo8etm the engine has a miss is there any way to isolate the injectors electronicly and can I pull fault codes through the dash. Where can I get a manual for this model I have found online manuals for all the older machines but nothing for the tier 3 machines. Thanks Jason

hi Jason,
i believe/think in an earlier post of yours i suggested that it would be best that you give me a call at work.
i'm in ontario.
my work # 1-905-888-9070
be sure to specifically ask to speak with me.
plus please e-mail me at " hf_hydraulics@hotmail.com " too.
ser# helps, its a hino j08e diesel eng
it has a separate ecu for eng and special hino dx software only released to the kobelco dealers if they made the expense to purchase it.
the only way to isolate fuel inj is with the software
if any fault codes displayed they'd be stored in the dash error history
as for a shop manual $500.00 - $600.00 dollars
i may have mentioned in my earlier post as well about bad fuel, contaminants such as a single water droplet will steam the tip off the fuel injector
i sell oem new replacements cheaper than i can purchase off cnh/kob themselves.
but you need hino dx software to program codes of each inj in the cyl you installed
likely due to water in fuel tank from condensation, dirty fuel or the use of non-apples-to-apples aftermarket fuel filters will cost you in these new common rail fuel systems.
the sk350 and some other models offer a opt kit to better the existing fuel filtration system in more severe working environments.
its worth the expense for if not we had one customer whom had to learn this themselves after we stressed what effects would be,...$ 10k later
he is now listening and will not chance any aftermarket filters.
call me if you want any help.
take care, chat tomorrow
adam

 

[MR. KOBELCO]

SK 60 1995 LE-17572. Well after 100 hours of on again off again service screen showing the wrench symbol it is back on for good. Worked fine all last week, run every day. Sat over the weekend and now have nothing but the wrench. After 2 days I guess it is not coming back on. Found a very recent Cluster controller but am hesitate at buying a third one. Still no clue as to why they fail or even if that is the problem. Should I be changing the wiring harness before ruining a third controller? How much is a new harness installed???
In too deep now.

hi,
please e-mail me at " hf_hydraulics@hotmail.com "
have your mailing address etc...
i'll quote you, but i'd want it at my shop this way i'll be on-hand to oversee the job myself.
adam

 

[Pane]

G'day

I'm in Australia and have a sk120 mark 5 super, the computer screen is all grainy and can't be read easily, where can I order on from? I checked with the dealer here and they wanted $1200.
MOdel number is lp15880

Cheers

 

[gregor1978]

Hello Mr. Kobelco,

I was on Linde hydraulics service training in Germany and was not able to reply You faster than now.
I will measure those values and than report to You next time when wisit this machine.
Now when I see this machine shematis of hydraulics system when I close eyes, I think that maybe also travel priority valve could couse this problem. Theoreticaly if this valve stucks in the midle position could cause pressure drop across itself. I dont know how big this p drop could be - but if big enaugh some power could be wasted there and than less will be awailable for other attachment.
Because bucket with pressure of 280 bar should pull complete machine when closing ( extending buck. cylinder). This machine reach max pressure and have no power. I think if everithink normal working this machine should pull itself with bucket at 250 bar?
On my first visit I noticed that cold machine had power on all attachments and than geting hotter power starting to go away..At that time I also noticed from pi signals that pump 1 is not engageing when closing the arm under full load, because pi1 was cca. 50 bar so pump 1 was at min. Also when closing arm under heavy loads for pump conflux is responsible travel priority valve and also arm conflux sequence.

On my last visit power on bucket was missing already when machine was cold.

Could all that be somehow conected that firstly problem started with wormer oil and now is present already with cold - i think now on travel priority and conflux pilot ?
What You think?

Thanks,
Gregor

 

[Vivian]

Mr. Adam, thanks so much.......

 

[gregor1978]

Hi Mr. Kobelco,

Today I pass by machine and I quickly measure some values.
1.) I could read engine rpm.
660 rpm and pf=30 bar
1300 rpm and pf=16 bar
1500-2150 rpm pf= 20 bar

2.) Yes, but today I did not have the time to measure Pi1 and pi2.
3.) Last time wasboth Pi at full speed 48 bar
4.) Yes at engine full speed 2150 rpm comp. vary the pf pressure. Like:
boom up 24 bar and 36 bar when reaching end
bucket opening 18 bar and 18 when reaching end

bucket closing 16 and 20 when reaching end for two seconds and than 16


arm retracting 10 bar and 30 bar when reaching end
arm opening 30 bar and 20 bar when reaching end


5.) ful rpm 2150 and starting arm away from cab pf goes dynamic 22bar-30-40 and 20 when reaching the end
rpm fell down from 2150 to 2073-2053
6.) raising boom 2150 rpm pf: 26-30- and stops at 40 rpm
rpm fell down to 2057-2029

Regards,
Gregor

 

[MR. KOBELCO]

Hi Mr. Kobelco,

Today I pass by machine and I quickly measure some values.
1.) I could read engine rpm.
660 rpm and pf=30 bar
1300 rpm and pf=16 bar
1500-2150 rpm pf= 20 bar

2.) Yes, but today I did not have the time to measure Pi1 and pi2.
3.) Last time wasboth Pi at full speed 48 bar
4.) Yes at engine full speed 2150 rpm comp. vary the pf pressure. Like:
boom up 24 bar and 36 bar when reaching end
bucket opening 18 bar and 18 when reaching end

bucket closing 16 and 20 when reaching end for two seconds and than 16


arm retracting 10 bar and 30 bar when reaching end
arm opening 30 bar and 20 bar when reaching end


5.) ful rpm 2150 and starting arm away from cab pf goes dynamic 22bar-30-40 and 20 when reaching the end
rpm fell down from 2150 to 2073-2053
6.) raising boom 2150 rpm pf: 26-30- and stops at 40 rpm
rpm fell down to 2057-2029

Regards,
Gregor

hi,
note:
engine specs
lo-idle = 875 rpm ( +/- 25 )
H mode (hi-idle) = 2320 rpm
S mode (hi-idle) = 2000 rpm
FC mode (hi-idle) = 1600 rpm
DECEL = 1050 rpm
( +/- 50 rpm )

pf sol hyd pressure at hi-idle under no load = 3 bar maximum

note: on arm in digging if the primary hyd pump (p2) does not reach X pressure the secondary pump (p1) which confluxes in to help will not receive the signal
from the arm sequence valve.

i am leaning to your fuel injection pump is worn out.
your engine rpms are low plus your pf solenoid pressures seem too high.

cheers
adam

 

[MR. KOBELCO]

G'day

I'm in Australia and have a sk120 mark 5 super, the computer screen is all grainy and can't be read easily, where can I order on from? I checked with the dealer here and they wanted $1200.
MOdel number is lp15880

Cheers

hi,
$ 1200 seems a fair price.
the cab display part number is locked off to my region on that model.
i have sold cab displays (which are a computer themselves too - " C3 ") for $ 2000.00 cad +
that seems cheap to me.
if much for you, try googling people have told me theyre available aftermarket out of singapore ?
adam

 

[gregor1978]

hi,
note:
engine specs
lo-idle = 875 rpm ( +/- 25 )
H mode (hi-idle) = 2320 rpm
S mode (hi-idle) = 2000 rpm
FC mode (hi-idle) = 1600 rpm
DECEL = 1050 rpm
( +/- 50 rpm )

pf sol hyd pressure at hi-idle under no load = 3 bar maximum

note: on arm in digging if the primary hyd pump (p2) does not reach X pressure the secondary pump (p1) which confluxes in to help will not receive the signal
from the arm sequence valve.

i am leaning to your fuel injection pump is worn out.
your engine rpms are low plus your pf solenoid pressures seem too high.

cheers
adam

Hi Mr. Kobelco,

What you write is all true but is not the main problem. When I disconect the el .wire to Pf solenoid, all problems are still there and also engine stalls when you push pump to hard. If I tried realy hard to lift lift ful bucket of rocks I coukd lift it litle more quicker than whith computer help.

What I found up:

1.) when prop valve disconected pf=0
2.) I tried to close bucket ( to fill it with 1-3 inch rocks) but bucket did not want to close and the pressure riest in moment to 290 bars ( I monitor only P1) and pump regulatet to 0 I think and engine did not felt enythink.
Than I pull right travel comand when all machine was blocked with bucket in rocks and I saw that travel relief is set to 350 bars. After that I pull travel comand to cca. 300 bar and also engage bucket for diging. Than sudenly bucket started to move ( close and loading the rocks) at pressure of cca. 200-250 bar. After that bucket and boom worked almost good ( but cca. 1/3 to slow) and arm still did not have power to tow complet machine when closing.
When bucked now was closing under heavy load I could here whiseling from valve I think.

I also notice that full loaded bucket is lifting with boom at 150 bar and real slow.
So I think that travel limiter could be cought somwere in the middle and throttle main flow. So could that be the couse? Could pilot pressure which suppose to lift the travel priority spool againstthe springs when engaging both travel and attachment leaks to that spool wheen it should not?
I attached the picture from which I think that is seen that this spool is forced in upper position ( from brown color which sould be oposide with bright part).
I will try to attach the immage here.

Regards,
Gregor

 

[ser repair]

problems with sk210lc hydraulics

I'm trying to get some help with locating the ports and fitting sizes for a sk210lc, s/n yoo7-uo978. For now I think I need to check the main pump(s) and pilot pressure ports. Problems are reported and seem to be 1. lack of didding power especially with the stick and bucket while cold. I have been told it get's worse after warming up. 2. the swing creeps even when cold. It has a Kawasaki pump with #'s as best as I can read "type" K3V112DTP.
Thanks for any help,
Ser

 

[gregor1978]

View attachment 92070

Hi Mr. Kobelco,

What you write is all true but is not the main problem. When I disconect the el .wire to Pf solenoid, all problems are still there and also engine stalls when you push pump to hard. If I tried realy hard to lift lift ful bucket of rocks I coukd lift it litle more quicker than whith computer help.

What I found up:

1.) when prop valve disconected pf=0
2.) I tried to close bucket ( to fill it with 1-3 inch rocks) but bucket did not want to close and the pressure riest in moment to 290 bars ( I monitor only P1) and pump regulatet to 0 I think and engine did not felt enythink.
Than I pull right travel comand when all machine was blocked with bucket in rocks and I saw that travel relief is set to 350 bars. After that I pull travel comand to cca. 300 bar and also engage bucket for diging. Than sudenly bucket started to move ( close and loading the rocks) at pressure of cca. 200-250 bar. After that bucket and boom worked almost good ( but cca. 1/3 to slow) and arm still did not have power to tow complet machine when closing.
When bucked now was closing under heavy load I could here whiseling from valve I think.

I also notice that full loaded bucket is lifting with boom at 150 bar and real slow.
So I think that travel limiter could be cought somwere in the middle and throttle main flow. So could that be the couse? Could pilot pressure which suppose to lift the travel priority spool againstthe springs when engaging both travel and attachment leaks to that spool wheen it should not?
I attached the picture from which I think that is seen that this spool is forced in upper position ( from brown color which sould be oposide with bright part).
I will try to attach the immage here.

Regards,
Gregor

I realy think that travel block is either defective or have some problem with piloting travel priorty spool. But how could I test that be sure?
I could check pressure which come from A2 ( independant travel valve), but how could I see that servo pressure does not leak throgh travel spool and goes to travel prioriti valve to engage it?
Or how could I test travel block for leaking? Normaly P1 should go from A port to D port but if leaking from A to C flow could be throtled and reliefed than to tank on arm side section of the block.

Regards,
Gregor

 

[rioncrsn]

kobelco 150 1991 ymu283

1) are you having trouble searching for new o.e.m., remanufactured, reconditioned, or new aftermarket replacement parts?
2) is your machine acting up and not running the way it should?
3) do you require help pin-pointing the root cause of the problem?
4) do you have any unanswered questions?
5) are you looking for manuals specific to your model and by serial number?

please post your topics here. i will do my best to help out.
as i am also sure and gladly invite the other experienced kobelco mechanics on this forum to ring in with advice as well!

thank-you!

i have a kobelco sk 150 all the hyd. work good except the lift boom had a frien of mine, which is an older man and retired mechanic look at it. he said after running it that a solenoid was not working properly and telling the second pump to cut on when the lift boom was being used. just wondering if you agree and if so were do i look for this solenoid and is it something i can fix myself. Thanks in advance.