This was a great explanation. I have a Hitachi ex230lc and i was curious about why the swing does not feel very accurate. My swing motor probably doesn't have the valve to stop the back and forth after i stop swinging. I read that checking the swing relief valves for contamination may help as well. Thank you again.
I just discovered your channel today , and the subjects are all clearly and in depth explained. This is realy helpfull and also enjoyable to watch , thanks !
Nice video, thanks for posting...I have a Hitachi EX120-3 with the same swing drive shown in your video with the anti-reaction spool option. Oil literally sprays out from under the front anti-reaction spool cover and bolt holes when swinging left. I replaced the O-ring under the front spool cover with an OEM JDeere O-ring and lapped the cover flat but it still leaks terribly. I'm thinking there might be a problem with the front swing relief valve after watching your video. Can swing relief valves be serviced/cleaned or just replaced?
Okay, well my mate has a 3t Bobcat Excavator, I think from their now discontinued series (machine's at least 8, not more than 15 years). I work on it for him, it has a good bit of rock to and fro on the swing bearing and almost every pin/bush is wore out on the boom, most concerning for me is it has free slew/swing movement at least to a degree (I haven't tested in depth), could this be related to the wet brake on the drive? Or maybe just that swing bearing again allowing all that free play between teeth? I also operate & work on a Komatsu LC605 Crawler Crane, which seems to be based on a 8.8t Komatsu PC80LC, the slew function is very slow, does seem to lock, but may have the free lift function you mentioned. I assume this is all by design - But what would be the cause of the slow slew/swing speed? Just a lower flow rate or maybe a greater gear reduction? It also seems to pull to the left when tracking, I figure this might be a tensioning issue, but it is a pain to check as it obviously lacks a standard boom with which to lift a track off the ground, is there another way to check or could it be something else?
Awesome instructional video, thnx! Ques- On a mini (hitachi 35), is there oil in the reduction drive? Wondering if that is something to change (not clear from the documentation) ~
Thankee, Think I'm ready to rebuild mine now... and figure out why its never really stopped swinging, it would slow down, but never stop, unless engine was off, then it stopped hard, so its either a secondary solenoid, or the pilot pressure is remaining on.
Is it possible to manually release the swing break? We are working on a bobcat e26 and have it halfway apart and meet to swing it a little bit to get bolts out.
Greta video. I have a ? Komatsu Pc 60. When u push left or right to swing sometimes the brake activates n abruptly stops. If I push a little coward adding the crowd cylinder it swings nice. So it seems the swing function is not always activating that pressure valve u talked about. Where would u start ur diagnosis? Thanks
How do the track drive motor's fluids get through the slewing mechanism? I presume there are no limits on how many rotations in one direction are allowed?
Can you help please. My Cat 311C swing motor, just serviced with new seals broke the two bolts holding it and bent the plate holding shaping it like a bowl. The left track motor has no movement. Both track motors were replaced recently. Where would such high pressure be coming from to bend the 10mm steel plate and lift up the whole swing motor. Your reply would be highly appreciated as the mechanic can't work it out. Just replaced the main hydraulic pump as well. It did the same thing , broke the bolts and bent the plate an don movement in the left track motor? Jason
Im running a 308 cat im geting a slight grinding noisewhen im swinging back as long as i swing slow it doesn't do it but when i dig fast it does it im not sure what it is it just started a couple days ago
I could come up with 50 reasons for any particular excavator. Multiply that by the hundreds of models with different systems from 2 dozen manufacturers... probably a thousand things could be listed. I'd have to run the machine, do some visual and basic tests, then hit the schematic and start looking for what's common to the swing and blade functions if I thought the symptoms were connected. I have 35 years experience working on heavy equipment and I wouldn't even begin to guess over the internet- waste of everyone's time.
working on a 425 bobcat mini excavator .If the seals were bad on the swing motor would that cause low system pressure throughout the entire hydraulic system.We have checked everything filters ,pump filters.main reliefs cannot figure whats going on.Buddy of mine told me if seals were bad in swing motor it could cause low pressure through the hydraulic system
@@hydraulics yes we did cut open old filter just pretty much a normal dirty filterFlow tested the hydraulic pump all up to spec.We tested main relief at main relief port on the excavator. by deadheading all functions.When we first start machine pressure reads over 3000 psi after 5 minutes drops to 2400 after 30 minutes drops to under 2000 psi.Main relief on control valve is the only thing we have not swapped over.Is it possible its bad ?Is a way to bench test a main relief valve?
I've got a question I hope you can help with. I have 2001 Cat 313B cr, if I'm on a slope my swing brake locks after 5 seconds and releases if I bump and hydraulics bucket, boom ect BUT my cab starts to swing towards gravity (downhill). Is this normal? I figured it would hold after the swing (park) brake is released. Thank you!!!
Loss off brake release pressure will cause swing to lock . Check for blown orings in pilot brake circut . Friction discs worn out also. Pilot Hydraulic pressure release discs. Rare for discs to wear out since they only hold machine not stop swing .
Hi! I have a Hitachi Zaxis 120 leaking Hydraulic oil from gear oil filler and dipstick on the swing motor. Any help or advice would be much appreciated.
The main seal at the bottom of the shaft of rotary group has probably done its work. Cause of it can be a high case drain pressure, so it’s probably necessary to also replace the rotary group. Also check if the case drain hose isn’t clogged so the pressure doesn’t build up in the hydraulic motor, because that could be the cause of the blown seal.
@@zanpetric4008 Thanks for the reply. it wasn't clogged. Rotary manifold rebuild didn't solve issue. (i didn't think it would but boss told me to do it.) We ended up replacing swing motor which solved our issue. Suspected valve plate or axial piston failure.
@@_maxstockwell rotary manifold has no connection to the swing motor, except the case drain in some cases from the final drives. By rotary group I mean the swing motor cylinder block pistons and valve plate (not rotary manifold). Your analysis could be correct. It’s good that you fixed the problem, but I still think the motor could be rebuilt. I just fixed mine (slew drift and low slewing power) and changed the main seal, rotary group and bearings (altogether about 700-800$/€ but nit the oem parts). Machine is tak 1140 which I believe has the same motor as yours-hms072?
That was a video that every owner/operator appreciates thank you for your time and I'm speaking for all of us. Thank you
You are such a dude! Working on a rotary... not had much luck... now I know what is wrong. Cheers, from the UK!!
Dang you answered a lot of questions...but made a lot more!!! Great video to start diagnosing a problem!!!
Incredibly helpful for the issues I’m diagnosing at the moment. Thank you.
This is incredibly helpful as I work to build my heavy equipment knowledge to learn to operate new machines at the mine.
Excelent lecture. I love your style of explanation. Stays in the head.
This was a great explanation. I have a Hitachi ex230lc and i was curious about why the swing does not feel very accurate. My swing motor probably doesn't have the valve to stop the back and forth after i stop swinging. I read that checking the swing relief valves for contamination may help as well. Thank you again.
Sounds great....loved this training
Thank you so much. Good explanation.🇹🇷
That is exactly what i wanted to know! great Video. Thanks.
Such a great video...off to fix my swing brake now.
I just discovered your channel today , and the subjects are all clearly and in depth explained. This is realy helpfull and also enjoyable to watch , thanks !
Glad it was helpful!
Great video. Thanks man
Nice video,and very nice explained. Can t wait to see more. Thanks
Great video! Very educational. Thank you
Nice! Thank you.
Appreciate your explanation awssum❤
Nice video, thanks for posting...I have a Hitachi EX120-3 with the same swing drive shown in your video with the anti-reaction spool option. Oil literally sprays out from under the front anti-reaction spool cover and bolt holes when swinging left. I replaced the O-ring under the front spool cover with an OEM JDeere O-ring and lapped the cover flat but it still leaks terribly. I'm thinking there might be a problem with the front swing relief valve after watching your video. Can swing relief valves be serviced/cleaned or just replaced?
Okay, well my mate has a 3t Bobcat Excavator, I think from their now discontinued series (machine's at least 8, not more than 15 years). I work on it for him, it has a good bit of rock to and fro on the swing bearing and almost every pin/bush is wore out on the boom, most concerning for me is it has free slew/swing movement at least to a degree (I haven't tested in depth), could this be related to the wet brake on the drive? Or maybe just that swing bearing again allowing all that free play between teeth?
I also operate & work on a Komatsu LC605 Crawler Crane, which seems to be based on a 8.8t Komatsu PC80LC, the slew function is very slow, does seem to lock, but may have the free lift function you mentioned. I assume this is all by design - But what would be the cause of the slow slew/swing speed? Just a lower flow rate or maybe a greater gear reduction?
It also seems to pull to the left when tracking, I figure this might be a tensioning issue, but it is a pain to check as it obviously lacks a standard boom with which to lift a track off the ground, is there another way to check or could it be something else?
Awesome instructional video, thnx!
Ques- On a mini (hitachi 35), is there oil in the reduction drive? Wondering if that is something to change (not clear from the documentation) ~
Very good video put more video
Great video
Thanks so much for this video
Thankee, Think I'm ready to rebuild mine now... and figure out why its never really stopped swinging, it would slow down, but never stop, unless engine was off, then it stopped hard, so its either a secondary solenoid, or the pilot pressure is remaining on.
Good Explanation
Nice video. So on my kobelco swing motor problem is that moves the rigth side on slope when I use the boom. What I can do?
Have you ever worked with Poclain motor or hydraulic pumps
Is it possible to manually release the swing break? We are working on a bobcat e26 and have it halfway apart and meet to swing it a little bit to get bolts out.
Greta video. I have a ? Komatsu Pc 60. When u push left or right to swing sometimes the brake activates n abruptly stops. If I push a little coward adding the crowd cylinder it swings nice. So it seems the swing function is not always activating that pressure valve u talked about. Where would u start ur diagnosis? Thanks
thanks for this video very interesting.
Nice video 🙏🙏
How do the track drive motor's fluids get through the slewing mechanism? I presume there are no limits on how many rotations in one direction are allowed?
Thancu weri match for very cuyt explenation swr
Tank you very much ❤❤❤
How can i hire you for a diagnosis?
Thank you very much¡👍
Grate video
Thanks for tacking 🙏🙏
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So helpful
Can you help please. My Cat 311C swing motor, just serviced with new seals broke the two bolts holding it and bent the plate holding shaping it like a bowl. The left track motor has no movement. Both track motors were replaced recently. Where would such high pressure be coming from to bend the 10mm steel plate and lift up the whole swing motor.
Your reply would be highly appreciated as the mechanic can't work it out. Just replaced the main hydraulic pump as well. It did the same thing , broke the bolts and bent the plate an don movement in the left track motor?
Jason
Amazing
So on my komatsu pc-28 it's slow to stop swinging to the left but works fine to the right so it's probably a check valve not the swing brake?
I'd check the relief valves first. Swap em left to right and see if the issue switches sides
hi.tanks
Im running a 308 cat im geting a slight grinding noisewhen im swinging back as long as i swing slow it doesn't do it but when i dig fast it does it im not sure what it is it just started a couple days ago
check swing bearing grease pan. check swing drive dipstick.
If the swing motor has internal leakage would that cause low system pressure ?
Low system pressure? Maybe when swinging... I'd need to know a LOT more
What would cause an excavator to swing extremely slow and not stop swinging on its own? The blade has minimal power too
I could come up with 50 reasons for any particular excavator. Multiply that by the hundreds of models with different systems from 2 dozen manufacturers... probably a thousand things could be listed. I'd have to run the machine, do some visual and basic tests, then hit the schematic and start looking for what's common to the swing and blade functions if I thought the symptoms were connected. I have 35 years experience working on heavy equipment and I wouldn't even begin to guess over the internet- waste of everyone's time.
working on a 425 bobcat mini excavator .If the seals were bad on the swing motor would that cause low system pressure throughout the entire hydraulic system.We have checked everything filters ,pump filters.main reliefs cannot figure whats going on.Buddy of mine told me if seals were bad in swing motor it could cause low pressure through the hydraulic system
Nope. How did you "check the main reliefs"? Did you cut the filters open to see what's in them?
@@hydraulics yes we did cut open old filter just pretty much a normal dirty filterFlow tested the hydraulic pump all up to spec.We tested main relief at main relief port on the excavator. by deadheading all functions.When we first start machine pressure reads over 3000 psi after 5 minutes drops to 2400 after 30 minutes drops to under 2000 psi.Main relief on control valve is the only thing we have not swapped over.Is it possible its bad ?Is a way to bench test a main relief valve?
@@jrac863 got a serial number of the machine?
@@mikerewegan9960 it is aacj11297 its a 2009 machine
I've got a question I hope you can help with. I have 2001 Cat 313B cr, if I'm on a slope my swing brake locks after 5 seconds and releases if I bump and hydraulics bucket, boom ect BUT my cab starts to swing towards gravity (downhill). Is this normal? I figured it would hold after the swing (park) brake is released. Thank you!!!
The friction disc are worn out
Loss off brake release pressure will cause swing to lock . Check for blown orings in pilot brake circut .
Friction discs worn out also.
Pilot Hydraulic pressure release discs.
Rare for discs to wear out since they only hold machine not stop swing .
Probably need to change the rotary group in the hydraulic motor. Check your case drain flow.
how to troubleshoot swing leaver malfunction lonking excavator
Hi! I have a Hitachi Zaxis 120 leaking Hydraulic oil from gear oil filler and dipstick on the swing motor. Any help or advice would be much appreciated.
Hydraulic leaking from motor to hear side check the motor seal
The main seal at the bottom of the shaft of rotary group has probably done its work. Cause of it can be a high case drain pressure, so it’s probably necessary to also replace the rotary group. Also check if the case drain hose isn’t clogged so the pressure doesn’t build up in the hydraulic motor, because that could be the cause of the blown seal.
@@zanpetric4008 Thanks for the reply. it wasn't clogged. Rotary manifold rebuild didn't solve issue. (i didn't think it would but boss told me to do it.) We ended up replacing swing motor which solved our issue. Suspected valve plate or axial piston failure.
@@_maxstockwell rotary manifold has no connection to the swing motor, except the case drain in some cases from the final drives. By rotary group I mean the swing motor cylinder block pistons and valve plate (not rotary manifold). Your analysis could be correct. It’s good that you fixed the problem, but I still think the motor could be rebuilt. I just fixed mine (slew drift and low slewing power) and changed the main seal, rotary group and bearings (altogether about 700-800$/€ but nit the oem parts). Machine is tak 1140 which I believe has the same motor as yours-hms072?
Is their any electrical connection with swing
There sure can be. Heck, Komatsu have an excavator with a completely electric swing motor.. no hydraulics involved . Thanks for watching!
What is a spec for case drain flow on a motor like this?
Rule of thumb, 5% of the flow being fed to it
@@hydraulicsso 5% of the main pump flow?
Have you encountered a cat excavator swing not working any idea
of course- I just showed you 30 + parts in this video, all of which could break, wear out or malfunction.
Hi cat 330DI exavator das not brack
also known as a SLEW drive
Excellent video!