Kobelco hydraulic excavators

[MR. KOBELCO]

I have a Kobelco SK045 Ser. No PY02469......The hydraulic fluid has a round bolted down plate on the top of the machine, which i presume is the fill cap to the tank.......In the battery compartment right in front of that is what appears to be a sight glass and about a 5/8 bolt right next to it......I'm assuming the sight glass is for the tank & the the bolt is the pressure relief......Are my assumptions correct......Thank You

hi,
if this bolt you describe is in the tank itself it would not be the relief.
your machine likely has a pilot system relief and a seperate relief for each hyd pump.
the pilot pump relief is likely in a manifold at one end next to a couple solenoid coils.
the main hyd pump reliefs will be part of the main hyd control valve.
each circuit will have overload port reliefs.
circuit protection when the function is not being utilised.
cheers!
adam

 

[MR. KOBELCO]

Yeah the lefthand stick created quite a mess. However, my thought was that there is some cross internal leakage in the boom joystick. Somehow when the pilot system is live the control spool is seeing pressure to activate yet when the pilot system is dead that boom is rock solid and doesn't drift down at all. If it were the boom cylinder piston seal/s or the holding valve then it would still drift down when the pilot system is cut off, I think. Ow, my head is starting to hurt!

hi,
it is quite possible that the plunger tiny spool in the joystick itself is sticking or bent.
the joysticks send the pilot oil signal to the spool to allow the function.
by lifting the lever lock up you have shut off the pilot oil to the joystick.
i would look for a sticking or slightly bent spool in that dirction controlling boom down.

adam

 

[MR. KOBELCO]

Thx for the help, Rippy. this machine is new to me. I have just been thru cleaning it up and getting it running again - mini rebuild you might call it. I'll get the RH joystick resealed anyway as it's not expensive. I will also follow your suggestion and tackle the hyd problems logically one step at a time. Need to begin by checking all the pressure points (picked up a 10,000 psi gage today) as you did and we'll go from there. Won't mind replacing seals, valve spools etc, but a little terrified of a major control block or pump/motor problem. However, it appears that the system was well designed, hydraulic was very clean including the tank (not a particle in it). So the problems are likely to be seals/stuck or dirty valve/broken spring. I see that this business requires a good deal of patience to track these problems down. Would not a leaking boom cyl allow the good cyl to pass thru it's oil too to cause leak down? Thx.

hi,
just a quick note, usually in hyd cylinders if the packings go and the hyd cyl is bypassing the rod will try to extend.
the piston is the greater area so as the pressures equalize within the cyl when not being actuated the force will be graeter push extend the retracting.
if suspecting internal leakage,...
extend the cyl rod fully. shut-off machine. remove the line on the rod end. cap/plug off machine side. take hyd line/hose of rod side open to a 5 gallon pail.
for lift boom cyl do both. start machine...dead end boom up once again...if the oil exiting the hose into the pail is more than a tea spoon...overhaul the cylinder.
cheers!

adam.
remember safety comes first.

 

[MR. KOBELCO]

I had an hour so I wanted to check a few more things so just to update

Rechecked negitive pressure with a new 1000 psi gauge at test pot Pi2 and had 400psi with high idle with lever lock up.... again specs are 455-668 psi

Teed into the pilot spool caps had 300 psi at PB .....Stalling swing to the right..... and 200 psi at PA stalling to the left

I have to jump on another job so I hope to check a few more items tomorrow but wanted to update my findings

Thanks Stephen

hi,
your 400 psi read can be due to a couple things...
a worn out neutral relief poppet cartridge, is likely...
or eng rpm's are down and below spec.
less oil flow will result in a lower pressure measured.
as far as the pilot prs readings on swing spool caps...the swing pilot circuit uses a couple shuttle valves...shuttle valve can also comprise of hyd ftgs assembled together with a ball and spring...could have a bad seat in shuttle the one way or deformed ball....
when you are ready to take all your readings i would suggest you first make sure the engine rpms are well within spec.
this is the first step
and yes you are right no computer, throttle is cable.
plus no solenoid one the hyd pump.
you may always call me and i can work with you the readings to take under which conditions first.
based on the findings i can give you steps to take to correct your machine.

adam

 

[rippy154]

If it is leaking by the packing the bad cylinder will drift down.....I had a sk120 that did what you described and it was a boom cylinder that had a blown packing

does you machine have a holding valve?? I saw one on a gray market machine that had a crane Orion or something like that.... I really can't recall

it kinda sounds like s circuit relief to me but hopfully mr. Kobelco will chime in since he really seems to know hydralicd

cheers and I will try my best to help u out

stephe

Man my spelling was horrible last night....that will teach me to go on the forum on my phone while the kids are running around screaming LOL....

Anyway I don't know what I was thinking when I was thinking of a holding valve but I was thinking of a "crane style holding valve" which I saw on a gray market machine with a crane option a long time ago........ not in the sense of a holding valve on an excavator in which the way the holding vavle works by preventing natural fall at neutral position.......

Plus after pulling the records on my 120 it wasn't a bad packing but pretty much a bad cylinder....the gland bushing was wiped out and the rod was bad so I think that is why mine was drifting down......sorry for the confusion but like I said I was just talking it out which I find sometimes sparks a good idea......"sometimes"

 

[Kobe130]

Many thanks to both Rippy and Adam for the help. Once I get the RH joystick resealed and see what it does I will post the results. Also I'm going to have to investigate the low swing situation - on top of hardfacing the new bucket and thumb for this machine - sheesh! Thx again. ointhead

 

[excel.ltd]

Hi Mr Kobelco

I have a Kobelco SK75UR which im told is around the year 2000 model.The problem I have is the 'rabbit' button just randomly decided to stop working!Do you know the location of the relay for this toggle switch or have any other advice or info I could use.

Thanks for your time

David

 

[MR. KOBELCO]

Hi Mr Kobelco

I have a Kobelco SK75UR which im told is around the year 2000 model.The problem I have is the 'rabbit' button just randomly decided to stop working!Do you know the location of the relay for this toggle switch or have any other advice or info I could use.

Thanks for your time

David

hi,
the only info i have to provide you would be a faxed copy of a page taken out of the parts catalog.
please e-mail me your ser# of machine YR-#####
and include your fax number.
if i cannot figure out faxing i'll have this page scanned and e-mailed to you.
my e-mail
[email protected]
cheers!
adam

 

[skc]

i am looking for help with my kobelco sk115srdz 2004, trying to pull the radiator. cant locate a service manual, i realize this is probably easy if you know the proper order to remove but it seams that i am missing something or may need to slide the counter weight back about an inch? all the coolers are loose from the brackets and hinge has been removed for the hood but still cant get the room i need. also have trouble with a cpu failure will discuss later. any help would be greatly appreciated.
not really sure if i posted this right

 

[MR. KOBELCO]

i am looking for help with my kobelco sk115srdz 2004, trying to pull the radiator. cant locate a service manual, i realize this is probably easy if you know the proper order to remove but it seams that i am missing something or may need to slide the counter weight back about an inch? all the coolers are loose from the brackets and hinge has been removed for the hood but still cant get the room i need. also have trouble with a cpu failure will discuss later. any help would be greatly appreciated.
not really sure if i posted this right

hi,
yes she's tight...please e-mail me at [email protected] i will scan the pages you require to help in the removal and reinstall of eng rad
please also include the serial number of your machine
YY0#-0####
cheers!
adam

 

[Ronsii]

Hi Mr. Kobelco, First let me say thanks for being on this forum and offering the great help and information like you do! It is always great to get answers to questions form a knowledgeable definitive source. Now for my problem we have a case cx36b mini # N7TN62187 # PX14-17228 apx2600 hrs. bought new in 07' it has been a great little machine but in the last few months it started tracking to the left, well the other day you could barely climb a slight grade as the left track just had no power so we finally ripped the controls (floor) apart and found that the shafts and the balls in the cams for the travel valves were worn so they will not push the spools in like they should, So we called the case dealer and they said they couldn't get a repair kit for that particular machine but they were willing to try one from a PX15 series... so I was wondering if you had any suggestions alternatives to fix these valves as the dealer listed similar kits for around $360 each(2 needed) and the valve for $960 (would probably buy the whole valve for only $240 more) of course we would like to fix this as cheap as possible but understand sometimes there is no cheap option. :0

One other thing not sure if this is a problem or just an annoyance... the tracks come off a couple times a week sometimes more if the person operating it doesn't boom swivel to turn the undercarriage when in loose dirt this mainly happens when operating in rocky/sandy soil conditions (bank run/type 17) the machine has done this since new, we have tried different tensions on the track from loose to very tight needless to say we use more grease to replace tracks then to grease the machine itself, so here again I was wondering if you had any suggestions as to how we can correct this problem. The machine has standard rubber tracks the tracks were replaced a couple hundred hours ago and the carriers and idlers look ok.

Again thanks for all the help and info you provide, Ron

 

[shinigamix2x]

Good day everyone, [despite we're all here trying to solve problems on our equipment], Here's my dilema
SK210LC Dynamic Acera - YQ08: Can't Swing and Track at the same time... had this problem a while now, changed a broken hyd. pump, changed some worn out solenoids yet that one particular problem still exists... any tips or know-how to solve this?
thank you, best regards to all...

 

[MR. KOBELCO]

Good day everyone, [despite we're all here trying to solve problems on our equipment], Here's my dilema
SK210LC Dynamic Acera - YQ08: Can't Swing and Track at the same time... had this problem a while now, changed a broken hyd. pump, changed some worn out solenoids yet that one particular problem still exists... any tips or know-how to solve this?
thank you, best regards to all...

hi,
is the travel straight propo-valve turning on sending a pilot signal measured with a 1,000 psi hyd prs gauge to the travel straight spool cap ?
adam

 

[shinigamix2x]

Sorry but i can't confirm that at the moment, i've re-checked the solenoid vavle assembly though since my co workers and boss purchased solenoid and installed them - okay just bare with me for a moment: THE A1, A2 AND A7 solenoids supposed to be the same, the A2 is different, the solenoid my boss purchased YB35V00006F1 supposed to be at A8, It was installed at A1 - the hyd. control lever did not work because of this - that's when i butted in and showed them according to the catalog which solenoid is for where! With that mix-up sorted out, the A8 got it's correct solenoid, the A1 also got it's correct solenoid, the A2 however, we gotta purchase a solenoid for this - YT35V00013F1, So my question is - could this be the reason why the Machine won't Track and Swing at the same time.

A1- LEVER LOCK, A2 - ATT BOOSTING, A3-P2 NUETRAL CUT, A4-TRAVEL PRIORITY, A5- P1 NUETRAL CUT, 6- ARM V. RECIRCULATION, A7 - TRAVEL 1/2 SPEED CHANGEOVER, A8- SWING
Are any of these solenoids the Straight Propo-Valve? if not where can i find it. Also the straight spool cap!

 

[MR. KOBELCO]

Hi Mr. Kobelco, First let me say thanks for being on this forum and offering the great help and information like you do! It is always great to get answers to questions form a knowledgeable definitive source. Now for my problem we have a case cx36b mini # N7TN62187 # PX14-17228 apx2600 hrs. bought new in 07' it has been a great little machine but in the last few months it started tracking to the left, well the other day you could barely climb a slight grade as the left track just had no power so we finally ripped the controls (floor) apart and found that the shafts and the balls in the cams for the travel valves were worn so they will not push the spools in like they should, So we called the case dealer and they said they couldn't get a repair kit for that particular machine but they were willing to try one from a PX15 series... so I was wondering if you had any suggestions alternatives to fix these valves as the dealer listed similar kits for around $360 each(2 needed) and the valve for $960 (would probably buy the whole valve for only $240 more) of course we would like to fix this as cheap as possible but understand sometimes there is no cheap option. :0

One other thing not sure if this is a problem or just an annoyance... the tracks come off a couple times a week sometimes more if the person operating it doesn't boom swivel to turn the undercarriage when in loose dirt this mainly happens when operating in rocky/sandy soil conditions (bank run/type 17) the machine has done this since new, we have tried different tensions on the track from loose to very tight needless to say we use more grease to replace tracks then to grease the machine itself, so here again I was wondering if you had any suggestions as to how we can correct this problem. The machine has standard rubber tracks the tracks were replaced a couple hundred hours ago and the carriers and idlers look ok.

Again thanks for all the help and info you provide, Ron

Hi,
in regards to your travel pilot valve
valve part# PM30V00019F1 subs to PM30V00019F4
kit, seal part# PM30V00019R100
suggested list @ $ 158.42 usd
kit, repair, cam x 2, balls x 4 part# PM30V00019R200 subs to PM30V00019R300
suggested list @ $ 335.00 usd

have you swapped the two over to be sure this is indeed the problem ?
the slow track should then swap sides too.
would just replacing the 2 balls on the worn out cam itself use ball bearings of a tad bit larger diameter may do the trick ?

as far as the tracks coming off - if you are not losing grease past track adj piston and the tension is holding,...
then you may want to purchase 4 of the bolton idler track guards used on the machine if as had track chains ?
this may help.
cheers!
adam

 

[MR. KOBELCO]

Sorry but i can't confirm that at the moment, i've re-checked the solenoid vavle assembly though since my co workers and boss purchased solenoid and installed them - okay just bare with me for a moment: THE A1, A2 AND A7 solenoids supposed to be the same, the A2 is different, the solenoid my boss purchased YB35V00006F1 supposed to be at A8, It was installed at A1 - the hyd. control lever did not work because of this - that's when i butted in and showed them according to the catalog which solenoid is for where! With that mix-up sorted out, the A8 got it's correct solenoid, the A1 also got it's correct solenoid, the A2 however, we gotta purchase a solenoid for this - YT35V00013F1, So my question is - could this be the reason why the Machine won't Track and Swing at the same time.

A1- LEVER LOCK, A2 - ATT BOOSTING, A3-P2 NUETRAL CUT, A4-TRAVEL PRIORITY, A5- P1 NUETRAL CUT, 6- ARM V. RECIRCULATION, A7 - TRAVEL 1/2 SPEED CHANGEOVER, A8- SWING
Are any of these solenoids the Straight Propo-Valve? if not where can i find it. Also the straight spool cap!

i just sent you an e-mail.
cheers!
adam

 

[Ronsii]

Hi,
in regards to your travel pilot valve
valve part# PM30V00019F1 subs to PM30V00019F4
kit, seal part# PM30V00019R100
suggested list @ $ 158.42 usd
kit, repair, cam x 2, balls x 4 part# PM30V00019R200 subs to PM30V00019R300
suggested list @ $ 335.00 usd

have you swapped the two over to be sure this is indeed the problem ?
the slow track should then swap sides too.
would just replacing the 2 balls on the worn out cam itself use ball bearings of a tad bit larger diameter may do the trick ?

as far as the tracks coming off - if you are not losing grease past track adj piston and the tension is holding,...
then you may want to purchase 4 of the bolton idler track guards used on the machine if as had track chains ?
this may help.
cheers!
adam

Hi Adam, Thanks for the quick reply, as for the cams we pulled them apart and flipped the cams around and turned the shafts over as they were worn on one side and the balls in the cams were worn about 1/8 inch(depth) to a flat spot some more than others, didn't switch sides may do that next time we have some down time just flipping them around made a marked improvement and nearly eliminated the play in the hand travel controls from side to side. One other thing I forgot to mention in the first post was if you moved the left control forward then also pushed it to the right(would move about 1 inch) it would speed up the track and would nearly track straight I suspect from the wear on the shaft and the sides of the balls actually both controls would sway side to side but the left control made a noticeable difference in track speed/power when you tilted it.

On to the track problem, I am pretty sure grease is not leaking but I will investigate this just to make sure but tension seems to hold right where we set it right up until the track comes off... I will also look into the idler track guards you mentioned, another idea we had was next time we put new tracks on it we were thinking about switching to regular chain and the bolt on rubber road pads as we have talked to some other operators running them and according to them they never come off.

Thanks again, Ron

 

[eric12]

Hi Mr, Kobelco.
i have a 1999 kobelco sk 200 lc that is dead. i was traveling along the job with it and it popped a 20 amp fuse for the starter circuit which killed the key switch and pretty much everything else. i had herd of a 30 amp fuse hidden inline behind the seat on the ground so i found that and it was good. any suggestions on where to start tearing the machine apart? it happened about 4 years ago also and after searching all over and testing all sorts of switches and parts it magically started and we had not had a problem since until now.
thanks for any help, Eric

 

[MR. KOBELCO]

Hi Mr, Kobelco.
i have a 1999 kobelco sk 200 lc that is dead. i was traveling along the job with it and it popped a 20 amp fuse for the starter circuit which killed the key switch and pretty much everything else. i had herd of a 30 amp fuse hidden inline behind the seat on the ground so i found that and it was good. any suggestions on where to start tearing the machine apart? it happened about 4 years ago also and after searching all over and testing all sorts of switches and parts it magically started and we had not had a problem since until now.
thanks for any help, Eric

hi eric,
please provide both your e-mail and serial number
yqu-#### to " [email protected] "
and i'll see what i can send off to you to help.
the 30 amp fuse located in behind the cab seat is for the cummins eng fuel shut-off solenoid.
when you replace the 20 amp fuse and turn the key switch please advise at which position the fuse actually pops.
on, acc, start, and so on...
cheers!
adam

 

[Kobe130]

Hi Gents, just starting to check hydraulic pressures on my SK130lc. According to Kobelco the traction motors need to be stalled and pressures measured at stall. In order to do this it looks like they offer a special tool which locks the sprocket but our local Mazer Group parts guys are not familiar with it. I think they`ve only been handling Kobelcos for a short while. Was wondering if this is something that most guys just fab up to hold the sprocket. Looks like the proper way to do it is to lock both sides at the same time. Don`t want to break anything! From the Kobelco test procedure sheet I could not really see what it looked like. Also I presume that by secondary pilot pressure they mean pilot pressure right at the (for example) swing control valve. Do you T into that pilot connection or dead end it to the gage or does it matter.