I am having an issue with the stick cylinder on my excavator, a 12000# Hanix without pilot controls and with a gear pump. If the stick is extended so gravity helps when you pull it in, it moves pretty fast for half the stroke, then pauses for severaI seconds once the stick is vertical. If you "stick out" during this pause it immediately moves out. Would this be a pump issue or a cylinder issue? Seems like the cylinder should only be able to fall as fast as the pump lets it but I'm no hydraulics expert. The guy I bought it from said he recently had the cylinders packed but didnt specify which ones, not sure if this would be a piston dealing problem anyway?
Good day If you have little or no creep - drift it is unlikely that the arm cylinder has an issue it could be that a restriction valve is open all of the time or could have a pump issue. Suggest you check what speed the cylinder can make with full engine speed be sure the engine revs are up to spec. If all the other function work good it is most probably a problem wit the cylinder circuit. Check the arm cylinder pressures if you have a hydraulic schematic we can help some more, if you know which Hanix could be a good idea to post this on the thread. Kind regards Uffex
If gravity doesn't help it it makes around 6 gpm which is the same as the bucket cylinder(which takes like 8 seconds to go from dump to curl). I've researched it and it's sposed to be a 14cc pump and I am not sure if it's the original pump because someone a Perkins 4-154 engine in it. I don't have a schematic but the parts book doesn't show any restrction valve, and lines go from pump through a block with check valves and then into the main valve body, individual circuits go from valve to cylinders. Not sure what the block does? No restrictor on cylinder parts diagram either. Model S&B 30 S. Engine rpms were about 2000, adjusted to 2550 and helped speed all the functions up but did not help with the stick issue.
Also-it has plenty of digging force and tracking power i'd say, just really slow. Also, no creep in cylinder at all. Once it's caught up or whatever it stays where u put it. Thank you for replying by the way. Mike
Good day Mike Often these machines are able to increase the flow for arm in -cylinder out by connection of another pump flow. Is there a switch in the cabin for increase in cylinder speed? KR Uffex
Could that be what that block is for? Both pressure lines from the pump go through it and there appears to be two spools. I haven't seen a switch but I'm still getting familiar with the machine, but I will look n get back to you.
Hi Mike A situation occurred to me from the past, when you experience this problem is it when the arm cycles above ground. If this is the case many machines do delay not so many folk excavate fresh air dare I say (No resistance against the bucket). I will try and get some information on your model but according to what I have found this machine had a Mitsubishi engine strange if its changed to Perkins. If I can find some information I will get back to you. KR Uffex
Thank you very much, I'm thinking that block is a crossover that puts flow from both sides of the pump into one circuit and it isn't working. I believe you pointed me in the right direction. I will post pics of the parts diagram n see what you think
Also on the engine....they modified the engine mounts and hood to get it to fit so I know it's not original
Hi Mike Im pretty sure this is your machine pumps please check and confirm. KR Uffex
No it does not look like mine. Here's a pic, and the one on the machine looks real similar to what it shows in the parts manual. I apprecoats your help.
That must be of a later machine it looks as though yours has twin pumps have you a shot of the valve chest, the information I have shows that the two pumps can connect to arm in cylinder out, we checked the time you had for the arm cylinder with 6 gallons flow 7.7 out 5.2 in so I believe the speed is good for one pump. KR Uffex
Common complaint, it’s just physics. A lot of the New machines do the same thing.
It's like a 5 second pause. I've ran excavator quite a bit and know what you are saying but this is extreme. Here are pics of the parts blowup for what I think is the crossover valve and another showing the plumbing. The two spool valves on the side are for the blade and boom sideshift and are completely separate circuits run off a belt driven pump. How would the crossover be actuated , if that's what it is?
Sorry about the blurry pictures. Can someone verify that it is a crossover valve? It looks like the two pressure lines from the pump go into this "block" as the parts book calls it and two out, one to either end of the valve body. There is a line that goes into the return pipe by the filter. It doesn't hook in to the stick out circuit that I can see. I'm curious how it is designed to work.
Have you attempted to make sure that there is no air in the arm cylinder circuit at all? When you say you have a 5 second delay is that when the stick is hanging perfectly vertical? Is this behavior the same at idle as full throttle or is there a difference in the lag time?
Happens when stick is vertical, yes, rpms don't seem to make much difference. I guess I've put 5 or 10 hours on and assumed the air would have worked itself out but maybe not? Would you crack the line that fills from the piston end and move the lever? Also that block has an adjustment rod with a locknut, maybe it's a pressure relief valve?
Ok. Gotta be totally straight with you. I dont see a problem. When you shift the spool, you're opening a passage to tank. Gravity takes over. The arm essentially falls till it hits the center of the arc or BDC , there it sits waiting for the oil to catch up and continue pushing. Normally the anti-cavitation function would allow enough make up oil to make it less noticeable. You seem to be working with a pair of fixed displacement pumps which won't compensate. I'd say you've got a good little machine. Uffex was trying to be polite when he said, "don't know many who excavate air."
That block I will bet is described or called out as anti-cavitation valve. If it is called out as summation or conflux then it's for 2 pump flow to gain speed. Gravity is on your side, you would only have 2 pump for arm out and boom up , I would think
Thanks for the advice, what you said makes sense. It does seem like a good machine, just slower than some. I noticed the pause moving brush. I sure appreciate everyone's feedback, I think uffex went to a lot of trouble researching it, Its good to know there are guys out there ready to help, hopefully I can return the favor. That block has an unreadable tag, simply listed as "block" in the parts book.
Good day Just caught up with your thread, the best help you can have is a hydraulic schematic and wiring diagram. for your machine, most if not all issues can be fixed with these two documents, I suggest if you intend to keep the machine try to get hold of these even if you cannot make sense of these we sure can. Have a good day. Kind regards Uffex
I will try and get those, manuals seem hard to come by. The parts book does have a wiring diagram but no hydraulic schematic. I do plan to keep it, I might buy a second newer mini at some point but this one shows 3128 hours and the meter still works, will probably run me a long time. Thanks again for your help, it is greatly appreciated. You guys probably saved me a fortune in trips to the hydraulic shop trying to fix a non-existent problem.
I see what you are describing all the time. The pump can’t put out enough oil so a suction valve opens a circuit to the tank to allow oil to be pulled into the cylinder. That provision is usually part of the circuit relief valve cartridge. Without seeing a schematic of the system we would only be guessing about which component to point at.
I don't have a schematic and I'm not sure where to find one. That block I mentioned must be some kind of suction valve? Its the only valve in any of the circuits besides the manifold that I can see. There is an adjustment on it.
What you guys all are saying is that this is inherent to a fixed displacement pump system, correct? Or is it worth having that valve rebuilt?
Good day Mike John C comment is spot on refilling of a negative pressure cylinder is provided by a simple check valve, this relies on some form of tank pressure, if you have a small breather filter on the tank try pressing the button on the top after stroking the cylinders, you should hear a rush of air if not it could contribute to your situation. Again if you had the Hydraulic schematic it would explain how the machine is meant to work. Normally dealers can get schematic it does not cost money to mail it to you, suggest you give it a shot. Kind regards Uffex
A good thing to do would be to strip down the stick cylinder and check the piston nut on the rod as it sounds loose to me, I am No expert but it would be easy to take a peep. tctractors
mce5802, you can do whatever you want, just keep in mind you're working with a mini ex . You have a simple linkage controlled valve bank. You may not have all the bells and whistles incorporated into larger/premium machines. If I were you, I'd ask the dealer servicing your area if this is normal for the line. I personally feel you're about to jump headfirst down the rabbit hole which will not you expense but also experience. My 2cents worth for the low low price of free. Good luck in whichever path you choose.
First mini I've run to speak of, you guys definitely know more about their operation than me. I think I will get engine rpms up to spec n leave it alone, use it next summer n see. will try n get schematics and service manual in the meantime. Thanks for the advice, it's always good to hear I dont have to spend money.
Good day Mike Contacted the local Hanix dealer he was real help full sent a parts book and Hydraulic schematic although its not very clear to my 70 year old eyes but I can see an adjustable restrictor on the negative side of the cylinder you could try half a turn may help your issue. Checked the parts book could not locate the valve but if you follow the tube from the cylinder you should be able to find it. Keep smiling Uffex
Missed one point pump "G3" has a possibility to help at low pressure via valve R4 this is the pump for the Dozer and swing cylinder I assume theses are working OK.
Update explanation
Again, thank you uffex. I can't view these files righ now but will try again when I get home. The pump for the blade works but is real slow. It may have too large of a pulley the guy mentioned he changed it. The block I mentioned before is bolted to the two valves for the blade and boom pivot, so what you said makes sense. I wasn't expecting you to go to all this trouble, but I greatly appreciate it. Could it be the auxiliary pump is turning too slow and causing this problem?
Good day Mike We can discount tank pressurisation as your machine is devoid of such a device, in view of what you stated regarding Pump 3 I would say there is a high probability that you put your finger on the cause of the issue. I have checked there is no specification for the P3 and I can only suggest you measure the revolutions and see if any label on the pump gives us the displacement, we can work out the flow from that info. You could appeal on the forum for other Hanix users to measure there dozer speed it would give us a base line to work from. Kind regards Uffex
Ok I will post a new thread, but I think you are right. I've found pictures showing the pump on an original mitsubishi engine and it shows it mounted directly to the timing cover, presumably splined into a gear driven off the crank. Who knows if the guys who did the motor swap paid any attention to the reduction, I'm guessing they did not. The blade will easily lift the weight of the machine, but moves pretty slow going both up and down. The blade has two cylinders, so I would guess it requires considerable flow to move at a reasonable rate.
old thread i know. i have an old sb30 i just picked up and wondered if yall had anymore pds of service etc. i cant find an id on the engine and i need a starter. local rebuilders cant find parts either
Good day I suggest you use the on line calculator to establish if the cylinder speed is correct click on the link. http://www.calculatoredge.com/ Kind regards Uffex
Ok, first, welcome to the forum. Go on over to "new member introductions " say hi and tell everyone what you're up to. Now, let's go back and start over. What I'd ask is to start a new thread. Make sure to list your machine model and serial number. If you can, include your engine model and serial number. A lot of folks won't pick up on a zombie thread cuz it's usually some foreign entity trying to pedal their products. Good luck.
ive searched and looked through the new threads and noone responds to new threads. Its a nissan sb30 with a 3 cyl diesel. all my research said they came with 4cyl diesels. there are no serial #s or markings on the engine. i drug this think out of a barn and been running it a year until the starter went out. took it to 3 starter rebuild shops and they cant find parts for the starter. ive ordered 3 starters online that looked exactly like the starter i have but bolt patterns where off or they was smaller. but ill start another thread if it can get my equipment going
If new threads are left hanging, it's usually because no one has anything to share. I won't usually get involved unless it's Komatsu or Volvo related. But general knowledge, everyone has their own twist. I don't know if there are still pic restrictions for new members or not, but if you can attach pics and any numbers you can find, no matter how obscure, that will give everyone a chance to help. Good luck. And mostly, welcome
This is common on most excavators, the stick is pulling the rod out of the cylinder by gravity, normally there will be an adjustable restrictor on the cylinder out line that can be adjusted to compensate for this and allow the piston to not run away from the oil. I'm not familiar with your brand of machine but a schematic will show if you have such a restrictor
Please note the recent posts. The original concern is corrected, another member is now having issue with obtaining a replacement starter for a similar machine.