I was looking at a 3.5t mini digger today (1988 Yanmar YB351, about 5000hrs); all looks to be ok with it (tracking straight, track chains not worn, engine quick to start etc) except she was unable to lift herself fully using the dozer blade and boom together. It would lift one or other end of machine at a time but not both together, so looks like its only fit to lift 30-50% of weight of machine. I also lifted it up on each side using boom to inspect track sag; no problems here with lifting. I also found the boom, dipper and bucket movements a little sluggish unless the engine was revved well over halfway (2450rpm max from engine plate), but maybe this is normal for this machine. Could this be an indicator of weak or worn hydraulic pump? or engine? or both? The engine loads and black smoke comes from it if I press the breaker pipe pedal (blanked off). I was under the impression that all mini diggers should be able to lift themselves fully & have been trying this test successfully on a couple of Kubotas. Thanks for all help here guys. I would have bought her today but this threw me. Anthony
I would expect it to. I've got a vintage Takeuchi TB15 (not a TB015) with a blown drive unit. It tracks in a circle really nicely. I lift the machine with its blade and it's leaking main boom and slide a pallet under it. I then use the fork to move it where it needs to go. Lift the machine again and remove the pallet and get to work. I hire a newer TB15 when I need it and that can lift itself as well. P.S. if anyone has a drive unit for a TB15 I would love to know.
Keep walking unless it's real cheap. If it can't lift itself it won't dig real well, as that is the digging force. However it may be as simple as resetting the relief valves, you won't know until you test the hyd pressures.
It Depends on how the set up with the pump are. Some minis have a twin pump set up with blade and swing on a smaller pump with lower reliefs and the main pump with work equip on a higher relief so you need to work blade down and boom lower to fully lift tracks off ground.
Yeah generally you put blade down first to make sure that the the machine is stable and going up straight, then use the boom to lift machine. However the fact remains that if the machine can't lift itself there is a problem.
yeah....uh, normally you dig with the bucket lifting instead of pushing down on the ground lol I wouldnt judge anything on it being able to lift itself. there are too many factors come into play, 1.maybe it wasnt designed for it 2.How far extended was the stick is the biggest factor! 3.How many times in normal life do you need to lift the machine just to watch the tracks go 'round? most Mini-Ex machines ive been on takes a little 'operators touch" to be able to lift the machine completely, you may have to hold the blade lever in the down position while you wiggle your stick while applying down pressure with the boom etc. but i deffinatly would not be scared of it just because it wont pick itself up completely, now if if wouldnt pick up one side with the boom over the side it would concern me, and even at that i would test pressures if i was interested and concerned. Pj
In order to 'excavate' with a bucket you need to 'dig' it into the ground. Guess you're thinking about mass excavating. Yes a proper excavator is designed to have enough power to lift itself, even if the boom and arm are extended, this is to say the breakout force is greater than the weight of the machine, otherwise you are using an inefficient machine. Or to put it another way the power of the hydraulics have to overcome the weight of the machine and not vice versa. I usually have to fully lift the machine up three or four times per job, twice just to expand/retract the tracks and the perhaps once or twice to clear the tracks of dirt. Also yesterday I did a job that required the machine to get over a 18" high garden bed with a questionably built wall around it, Was quite handy to be able to use the blade and bucket to gently place the machine on the top and to try and keep the weight off the wall. Yes some of the older machines do require a bit more to lift themselves but my I stand by my earlier comment that unless the machine can be bought cheap or a least fully assessed as to what could be the matter with it, I would not buy it.
You do realize that cylinders have more power one direction as apposed to the other dont you?..... Break out force has nothing to do with applying down pressure So youre telling me that everytime you fill your bucket you pick the machine up off the ground? maybe you need to learn some new digging techniques, there is no reason you should have to apply down pressure to fill the bucket every time.....try digging at the end of the trench or hole that is closest to you. there is no way that I will believe that the 10-12 mini hoes I have owned and operated was weak on power......especially not the brand new ones . There is NO POSSIBLE WAY that anyone could say without a doubt that ALL machines are supposed to operate exactly as another brand would. maybe the machine he is looking at is a conventional machine and the blade is 1 foot farther away from the idlers than on a zero tail swing machine, or that the one he is looking at has a longer stick than the others or its just that the manufacturer couldnt see any possible or theoratical reason for the need to make thier machine do what is being described. or maybe there is something wrong with the machine it's hard to say, but untill someone with the same model of machine makes a post.....and maybe even post a pic of boom/bucket placement with the tracks completely in the air I'm not being mean or doubting your ablility as an operator but maybe a little more finnesse instead of brute force would make your machines last a little longer that's all.... Pj
I operate in all sorts of conditions and job types, this means that 'sometimes' I need to apply full down force on the bucket in order to penetrate the material. Unfortunately I don't just work in nice conditions with soft loamy soil. Sure most of the time I have the blade out front to give more 'pulling' power but sometimes the blade is out the back to give more penetrating power. On some jobs I may even swap around and start with the blade out the back and once have a hole to work in, will spin the undercarriage around. And it is not a matter of brute force but rather getting the most out of your machine.
...My '02 Tak 016 will lift itself, however I do need to have the boom in close.This machine requires raising to extend or retract the treads. Granted this is a mini,1.75T,and I'm not a professional operator but I would guess that at lower engine speeds it would be normal for the equipment to respond slower.IIRC there was quite a discussion re: engine speed 'Do you run @ 100%' or similar was the thread. The black smoke would scare me off though. But I'm in California.The officials want me to be scared of black smoke Good thing I'm under 25HP!. Skies. Jay.
I ran a cat 307 a couple of years ago and when we used other attachments we had a valve by the engine compartment we had to turn,now I know for the hammer it supposedly redirected the oil flow but im wondering if this machine you mention has the same setup or if it would even make a difference on it or the cat.
In mining we pick one side of the machine up to turn it,less wear on the tracks and less chance to lose a track,it also is easier on the ground in environmentally sensitive areas. In pipelining it's imperative to know how to walk over an excavated ditch to redig it and in construction it's how I have allways dug trench for culverts,dig both sides,lift and turn and walk off the trench. I did a culvert type excavation last month and the new boss said"thats nice but how are you gonna get out without flipping"? I lift and turned and walked off and he just shook his head and drove away.
My Grey Komatsu PC50 uu-1 has 3 fixed displacement pumps. Its a simpler system and is stout but slow. It has linkge controls like an older tlb. The pumps are linked one for each track or for each of the digging motion. The thing will walk and boom but will track to the right run the stick walking it will track left. It will pick its self up with blade and boom together but the functions cant be used full force together. The boom will over ride the blades lift. Also when picking it up the relif vlave for the blade will open sometimes wen lifting its self.
Note that the force that is going to raise the machine up, has to be vertical.So you need two movements, boom down and stick open. Hope that helps!
didnt read all the posts but have you checked to see if the merge/divide valve is working?????