Sounds like swing motor seal went bad. Need to measure case drain off motor. Motor could possibly be shot
Mbar said:Sounds like swing motor seal went bad. Need to measure case drain off motor. Motor could possibly be shotClick to expand...Not necessarily shot, it could be rebuildable
Good dayThe attached may be helpful.Kind regardsUffex
One more question.it seems everyone agrees the swing motor needs to be replaced or rebuilt.I have talked to the local Takeuchi dealership and they say the swing motor is on back order but costs $22,500.00. And they do not sell rebuild kits or individual components of the motor.The part number is HMS072AG8TA. I found it through a Chinese company called Urparts. They ship via dHl and claim it will arrive to my door in Texas in 4-6 days. Through them it’s 2,100 with shipping. I’m a bit worried about send 2000 bucks to China but don’t see any other options?
Worth a call
Hi JeremyMy suggestion would be to check out the case drain pressure first, normally those components are good for 10,00 hrs, other components can have an adverse effect on the life (A worn slew ring bearing) for example. Take it one step at a time measure the case drain when you swing-slew, I interpret you are going to have to pull the transmission- ask for dealer support at this point, if the machine is young they should take an interest. We are here to give you support, many guys subscribing have a vast knowledge, treat it all as a learning curve.The case drain should be low less than 12.psi.Take careUffex
Serial number for machine and part number from Takeuchi.One serial number range crosses to a Hitachi ZX120.You didn't state how many hours on unit.Since you're essentially down, pull the hydraulic filter and inspect for brass.
I don’t know what part of Texas you are at, but there is a very good hydraulic shop in Irving, Texas. They could possibly build your swing motor or find you another. I had a drive motor that the dealer wanted 10,000 for and they had one on the shelf for 2,500.
See if there is a manufacturer id tag on the motor
Probably a poclain.
Another simple test that doesn't require gauges is a flow test. To do this put the casedrain hose into a pail, with the slew stalled start the engine and rev to wide open throttle, activate the slew fully for 1 minute then shut everything down. Now measure how much oil is in the pail.Scratches on valve plates and swash plates can be lapped out as can the brass ends on the slippers if the motor isn't to bad a shape else were. New bearings should be easy to find, the part numbers for those can be found on your bearings and cross over to many different manufacturers ie SKF, FAG,Timkim etc. The outer shell should also be replaced with the same manufacturers bearing.Purchasing parts from the machine dealer is something I've avoided because they charge like a wounded bull. An example, planetary drive and motor from the dealer $14000, rebuilt with new parts $4500
Here’s a pic
Here’s the part from China, they sent me a picture of it and it’s an exact match as the one on my machine.
I appreciate all the great advice on troubleshooting and testing but I’mEmbarrassed to say I’m not sure what a lot of it means. I’m not much of a mechanic.I’ve boiled it down to three options: 1. I found another dealership that will put a new swing motor in for around 12,000 dollars.2.I could pull the pump and have someone rebuild it for a lot less.3. I could wire $2000 to China and try to buy the one in the invoice.my question is this, before this happened the swing break was not working. If I understand correctly the swing brake is inside the swing motor, so I figured if I did but the new one it would solve that problem also. Do you think if I have it rebuilt that they rebuild the brake part of it too?Sorry if these are dumb questions.Thanks in advance
2600 hoursheymccall said:Serial number for machine and part number from Takeuchi.One serial number range crosses to a Hitachi ZX120.You didn't state how many hours on unit.Since you're essentially down, pull the hydraulic filter and inspect for brass.View attachment 250512View attachment 250513Click to expand...
You can give Tracy Triplettt a call at SHP Hydraulic Pump Service in Pacolet SC.
good dayItems 17>21 are the swing (Parking brake) part of the motor assembly.Kind regardsUffex
My opinion is this. Don’t buy the one from China. If you don’t feel confident doing any of the tests that people are talking about, it might be time to look for and call in a reputable mobile mechanic, or have it brought to an reputable independent mechanic, $12,000 seems like an awful lot of money to have a swing motor replaced. Like I said, it “sounds” like a lot, but I haven’t ever had to do one or have one done so I really don’t know if it’s expensive or not. I would reach out to some of the places people have recommended on here and give them the numbers off your swing motor and see what they say. Also, I would have to imagine that your swing brake issues probably had something to do with the failure. If the hours are correct that seems like a premature failure but stranger things have happened. What’s the overall condition of the machine?
Don't send squat to China. Start looking at the options you have been given by others. Google that Hitachi model number and see what pops up. Trywww.flinthyd. com also. I bet there is one around and at a good price.
You may have blown seals in the brake I would tear it down and see what is going on before replacing HSP is a good place to send it if you don't have anyone near you
Jeremy, if you go down the China route then you and your son can get mechanical and pull down this motor. They aren't that complicated. A clean work place is essential and doing stuff in an orderly manner like laying out the parts as the come out and the correct way up. Assembly is the reverse procedure so last parts out are first parts in. There are plenty of blokes here who can help and advise.An Australian expression " have a go ya mug" applies as you'll gain more than you'll lose and end up with a better quantity job than the China purchase if done correctly.
I've had swing brake issues in the past with one of my Bobcat machines and find myself wondering what will come of this issue for the OP. Based on the way that the OP has responded I think that he will likely go with the Chinese swing motor. He said that it is the exact same motor with all the exact numbers as his OE motor. It seems as though he is very reluctant to disassemble the original part to investigate, or hire a mobile mechanic to check things out either (which is possibly going to be the quickest way to get him up and running, and keep the high quality OE parts in place too). Based on his picture the motor is made by Hitachi. If one is dead set on throwing a new swing motor at the problem then looking for this via a Hitachi dealer seems like a good option (as suggested by others). Furthermore there are many other sources for Hitachi motors and pumps within the US. While I do subscribe to the belief that it is always better to source parts within the US (especially vs. China) a big concern for me would also be whether, or not, could trust the product that he is possibly going to source from China. Even if the item looks to be exact/OE, is it counterfeit? What type of guarantee does it have and will they even honor it? Who pays for shipping if returned? What if the second unit is subpar? Just too many unknowns for me to feel comfortable.To the OP: Based on my 40 years in excavation, I think that you have been given some sound advice on how to proceed in a way that will work best for you in the long run. Sure, it is possible that, even after you go through some trouble shooting, you may end up having to replace the swing motor anyway. But once you mentioned the swing brake not working, most everyone here, including myself, feel pretty strongly that your entire issue (or rather both issues) might be resolved with some new o-rings. I do have one line of thought that has me question this but I will address that below. Regardless, I hope you get it fixed either way. If you are not comfortable tearing into things on your own, hopefully you can find a good mobile mechanic in your area (those guys are super busy in my area right now and backed up for some time) that can help you get up and running without much drama. If you do, will also have made a relationship with some one who could be there for you don the road as well (for whatever issue/s that may arise in the future).As it relates to the swing brake. The OP has now stated that the swing brake "was not working" before he noticed the oil leak. I wish we had a better definition as to what the exactly means. For the benefit of the OP, and anyone else who may not know, lets talk about some of the basic operating principles of the swing motor (at least as I understand them. Feel free to interject/correct if I may not be completely accurate). Lets use heymccall's diagram (thank you for posting it) to help illustrate. The swing brake (spelled like brake, not break, because it provides braking) is usually found at the top of the swing motor. If you look at that image everything shown on the left side of the diagram makes up the parts of the swing brake. It is a wet, multi-disc unit (more like a clutch). Within the assembly is a/are spring/s which are always trying to apply pressure to the discs and plates which forces them together. When the plates and discs are pushed together they create the friction required to make it so that he swing is locked. When locked the super structure of the machine will not rotate separately from the undercarriage. When the operator asks for the machine to swing (by moving the appropriate lever) hydraulic oil is routed to apply pressure to a pressure plate (usually known as the piston), which then starts to over ride the pressure applied by the springs. This allows the plates to separate, reduce, and ultimately relieve, the friction that has been preventing the swing. Of course oil is also directed into the motor so that hydraulic force is applied to the direction that the operator wants to swing. With that in mind, if the seals on that piston are bad the swing brake usually doesn't release. This makes the swinging very difficult, and often doesn't happen at all. If the OP's definition of "the swing brake wasn't working before the oil leak" is that it wouldn't, or was reluctant to, swing then I think that a bad piston seal is quite likely the cause of excessive oil bypass and case drain pressure. If the swing brake would not stop the slew when the operator released the handle then we may have a different issue unless hydraulic oil pressure is also used to apply the swing brake in this particular swing motor (this is where a mechanic can chime in to confirm, or deny, if hyd pressure is required toapplythe swing brake vs. just toreleasethe brake). Case drain is the "waste oil" (I use that term because the oil doesn't apply any force to the intended function) that has leaked past seals in a given compartment. It is common for many hydraulic motors to have a certain amount of case drain oil so there is usually a return line to drain said oil back to the hydraulic tank.If the piston seal, of the brake, is bad then excessive case drain oil pressure will likely be the result. Case drain pressure is generated when there is more oil trying to get back to the hydraulic tank than the line can easily flow without creating a restriction. That is why many have suggested that you check the pressure in the case drain return line for the swing motor.Whew!! I'm out of breath now!In any case, I'm not overly confident that we will hear back with the final result. The OP only has (10) posts, and just joined the forum on the 18th. One can easily conclude that he did so only to resolve this issue and we may never hear from him again.Vetech63, are you on the back of the D&SNG in your profile picture?
I, the original poster, am still here!When this breakdown happened I did my best to learn how the offending mechanism worked, list my option on how to fix the issue, and get the opinions of folks like yourself who know way more than I.initially I noticed when traveling the (forgive the lack of proper terminology) cab, would swing and the boom would turn to the lowest point int the circle, when digging I would swing to my dump point and release pressure on the stick to stop the swing but it would continue another 45 degrees or so. With the great info supplied by some of the awesome people on here, and some digging into the parts catalog I purchased online I began to form a rudimentary idea of how it works.I continue to use it for a couple more hours until ALL the hydraulic oil in the machine drained out the gear oil fill tube on the swing motor.After weighing all my options I decided to take it to a hydraulic repair shop near me. I spoke with the owner and he seemed confident that he could rebuild the pump and fix the brake at the same time. He seemed very knowledgeable and honest. The ballpark quote to fix it was very cheap compared to the Chinese swing motor that was $1300 plus $700. And VERY VERY cheap compared to the $22,500 the the Takeuchi dealership quoted me.I did not mean to leave anyone hanging it’s just a busy time around head weaning calves and getting cows moved around in advance of pending cold fronts. I will post and update when I get the excavator back from the shop. Feel free to ask any questions and I’ll do my best to answer.ThanksJeremyDGODGR said:I've had swing brake issues in the past with one of my Bobcat machines and find myself wondering what will come of this issue for the OP. Based on the way that the OP has responded I think that he will likely go with the Chinese swing motor. He said that it is the exact same motor with all the exact numbers as his OE motor. It seems as though he is very reluctant to disassemble the original part to investigate, or hire a mobile mechanic to check things out either (which is possibly going to be the quickest way to get him up and running, and keep the high quality OE parts in place too). Based on his picture the motor is made by Hitachi. If one is dead set on throwing a new swing motor at the problem then looking for this via a Hitachi dealer seems like a good option (as suggested by others). Furthermore there are many other sources for Hitachi motors and pumps within the US. While I do subscribe to the belief that it is always better to source parts within the US (especially vs. China) a big concern for me would also be whether, or not, could trust the product that he is possibly going to source from China. Even if the item looks to be exact/OE, is it counterfeit? What type of guarantee does it have and will they even honor it? Who pays for shipping if returned? What if the second unit is subpar? Just too many unknowns for me to feel comfortable.To the OP: Based on my 40 years in excavation, I think that you have been given some sound advice on how to proceed in a way that will work best for you in the long run. Sure, it is possible that, even after you go through some trouble shooting, you may end up having to replace the swing motor anyway. But once you mentioned the swing brake not working, most everyone here, including myself, feel pretty strongly that your entire issue (or rather both issues) might be resolved with some new o-rings. I do have one line of thought that has me question this but I will address that below. Regardless, I hope you get it fixed either way. If you are not comfortable tearing into things on your own, hopefully you can find a good mobile mechanic in your area (those guys are super busy in my area right now and backed up for some time) that can help you get up and running without much drama. If you do, will also have made a relationship with some one who could be there for you don the road as well (for whatever issue/s that may arise in the future).As it relates to the swing brake. The OP has now stated that the swing brake "was not working" before he noticed the oil leak. I wish we had a better definition as to what the exactly means. For the benefit of the OP, and anyone else who may not know, lets talk about some of the basic operating principles of the swing motor (at least as I understand them. Feel free to interject/correct if I may not be completely accurate). Lets use heymccall's diagram (thank you for posting it) to help illustrate. The swing brake (spelled like brake, not break, because it provides braking) is usually found at the top of the swing motor. If you look at that image everything shown on the left side of the diagram makes up the parts of the swing brake. It is a wet, multi-disc unit (more like a clutch). Within the assembly is a/are spring/s which are always trying to apply pressure to the discs and plates which forces them together. When the plates and discs are pushed together they create the friction required to make it so that he swing is locked. When locked the super structure of the machine will not rotate separately from the undercarriage. When the operator asks for the machine to swing (by moving the appropriate lever) hydraulic oil is routed to apply pressure to a pressure plate (usually known as the piston), which then starts to over ride the pressure applied by the springs. This allows the plates to separate, reduce, and ultimately relieve, the friction that has been preventing the swing. Of course oil is also directed into the motor so that hydraulic force is applied to the direction that the operator wants to swing. With that in mind, if the seals on that piston are bad the swing brake usually doesn't release. This makes the swinging very difficult, and often doesn't happen at all. If the OP's definition of "the swing brake wasn't working before the oil leak" is that it wouldn't, or was reluctant to, swing then I think that a bad piston seal is quite likely the cause of excessive oil bypass and case drain pressure. If the swing brake would not stop the slew when the operator released the handle then we may have a different issue unless hydraulic oil pressure is also used to apply the swing brake in this particular swing motor (this is where a mechanic can chime in to confirm, or deny, if hyd pressure is required toapplythe swing brake vs. just toreleasethe brake). Case drain is the "waste oil" (I use that term because the oil doesn't apply any force to the intended function) that has leaked past seals in a given compartment. It is common for many hydraulic motors to have a certain amount of case drain oil so there is usually a return line to drain said oil back to the hydraulic tank.If the piston seal, of the brake, is bad then excessive case drain oil pressure will likely be the result. Case drain pressure is generated when there is more oil trying to get back to the hydraulic tank than the line can easily flow without creating a restriction. That is why many have suggested that you check the pressure in the case drain return line for the swing motor.Whew!! I'm out of breath now!In any case, I'm not overly confident that we will hear back with the final result. The OP only has (10) posts, and just joined the forum on the 18th. One can easily conclude that he did so only to resolve this issue and we may never hear from him again.Vetech63, are you on the back of the D&SNG in your profile picture?Click to expand...
The swing brake, at least on my Caterpillars, is misleading.The brake is applied at machine off. When pilot is engaged, the brake remains applied until ANY boom, bucket, or arm function is requested. At that point, the swing brake releases and the swing remains stopped, due to dead ended oil.If a swing function is requested, the swing brake will release and swing will occur.Here's where it confuses. When you stop swinging, it's NOT the brake that stops you, it's the dead ended oil.Once all boom, bucket, arm and swing motion requests stop, the brake applies 6 seconds later.If you have a "fine swing" option, and it's activated, a small crossover passage between the CCW and CW oil supplies is opened, allowing for "finer" control of the swing, giving the dead ended oil a place to go slowly, giving "finer" control.Nutshelled...swing motion is stopped by dead ended oil. The brake is only to prevent unwanted movement when not operating.
JeremyWillis said:I, the original poster, am still here!When this breakdown happened I did my best to learn how the offending mechanism worked, list my option on how to fix the issue, and get the opinions of folks like yourself who know way more than I.initially I noticed when traveling the (forgive the lack of proper terminology) cab, would swing and the boom would turn to the lowest point int the circle, when digging I would swing to my dump point and release pressure on the stick to stop the swing but it would continue another 45 degrees or so. With the great info supplied by some of the awesome people on here, and some digging into the parts catalog I purchased online I began to form a rudimentary idea of how it works.I continue to use it for a couple more hours until ALL the hydraulic oil in the machine drained out the gear oil fill tube on the swing motor.After weighing all my options I decided to take it to a hydraulic repair shop near me. I spoke with the owner and he seemed confident that he could rebuild the pump and fix the brake at the same time. He seemed very knowledgeable and honest. The ballpark quote to fix it was very cheap compared to the Chinese swing motor that was $1300 plus $700. And VERY VERY cheap compared to the $22,500 the the Takeuchi dealership quoted me.I did not mean to leave anyone hanging it’s just a busy time around head weaning calves and getting cows moved around in advance of pending cold fronts. I will post and update when I get the excavator back from the shop. Feel free to ask any questions and I’ll do my best to answer.ThanksJeremyClick to expand...I'm glad that you were able to find some assistance locally. It sounds like it will be at much less expense and risk too (as others had advised here)! Win-win for you! I think you'll be glad you did in the long run as well. Thanks for the update.
It is also good to build local relationships like that. Hoping it all goes well and if you need, this shop can help you in the future.
As above
Quick update. The excavator has been at the hydraulic shop for over a month!!!! It’s finished now, picking it up Monday. The seal on the bottom of the swing motor where the spline comes out, just above the reduction gear was blown. He took apart the entire swing motor and rebuilt it. So it essentially like new. What worries me is that he said everything in the motor was in excellent condition (minus the blown seal). He told me it would have taken around 4000 psi to bust the seal. But with no other problems found in the motor I’m concerned that we fixed the seal but not the cause of the failure?The other thing I’m worried about is that before this breakdown the swing brake was barely functional, if at all. It would over swing way past the point you that you stop slewing. I was expecting there to be something wrong with the brake system in the motor but when he rebuilt it all he said it was all perfect? He hasn’t been able to test the brake since it’s in the shop but I’m assuming it still has the same problem. I guess that process of elemintion would tell us that the problem isn’t in the motor, if my understanding of the way it works is correct that would only leave the solenoid that engages/disengages the brake? Your thoughts?thanks
I would say you are going to want to install a pressure gauge in your case drain line when you put this fresh motor on. Maybe something downstream has failed?
Forgive the dumb question but I’m not much of a mechanic. To do that I guess I can just put a “tee” in the line and put a hydraulic pressure valve on the T? Do you know what to look for? I’m assuming the return line would be really low pressure?
High case drain pressure would've destroyed the brass slippers.Believe it or not, seals can fail just from age, time, and exposure.As for the overswing, I believe it's a valve issue.
Thank you guys for your patience with my dumb questions but beside the over swing it also swings really bad when you’re traveling on its own, not a powered swing but it’s always swinging the boom towards the lowest side. It’s bad enough you have to drive with your feet and hold joystick pressure against the direction the boom is drifting. Just for kicks I extended the boom all the way straight out at ground level just a couple feet of the ground. I shut the engine off and got out and I could swing the boom by hand! Anyway all of this was prior to the rebuild so hopefully it’s fixed, but again the mechanic said everything in the swing motor was in excellent condition and he didn’t find anything wrong. Going to get it out of his shop and test it tomorrow morning.It just confuses me because my understanding was that the swing over run and the brake while traveling were two different braking functions. Meaning that the overswing would be stopped by deadending the hydraulics while the traveling and parked aspect would be the internal brake discs? It seems weird that both would be not working while the motor and all the internal parts were in ‘excellent’ condition?!?! I would think the disc brake problem would be narrowed down to a problem outside the motor like a valve or solenoid but I would have assumed the mechanic would have seen a problem inside the motor for the hydraulic “dead ending” brake. Aren’t they two separate systems? Or could one problem outside the motor cause both systems to not work?