Hi,,I have purchased a Bantam 266-C to dig my basement, driveway, road thru woods, ect. I plan to sell after I'm done with these projects. Everything is ok until we found 1 problem. This machine has the "stick" controls and "bucket curl" on floor pedals. When bringing stick in, at the last of the travel, the pedal sticks down,, and you must STOMP the "out" pedal to unstick it. While it is stuck, it drags rpm way down,,as expected, but does not kill engine. This excavator sat for 2 yrs. We did not get it to stick while testing function before purchasing,,,,,,,,naturally Any suggestions for fix? I'm guessing a valve?
Could be the centering spring mechanism on the backside of the valve, could be linkage/pivots. Disconnect the linkage where it connects to the valve spool, then see how free the pedal is. If it's still sticky or stiff to move, you've got a rusty linkage or linkage pivot problem.
Pedals seem to work easy when machine not running. I will disconnect linkage to be sure though. Is this "centering" spring mechanism external, or inside valve?
Huh??? Mind you, I haven't worked on one of these, but that sounds weird. I was thinking the machine might have linkage controls as opposed to hyd pilot operated controls because hyd pilot controls generally don't have "sticking" problems. Can you give us a little more description of how the controls and pedals work the valves?
The pedals are on linkage as you say. They go thru the floor to a swivel point. There they are connected by adjustable linkage to a long rod which goes back to the valve,,maybe 6-7 feet back. When I say the pedals seem to work easy when machine is not running,,,,I meant they will not stick when pressed to the floor,,,they come right back up. So I assume it is a hyd problem as they only stick when machine is running. When you press the left pedal,,it forces the right pedal back up,,since they both cannot be down at the same time,,,,,,but when it sticks,,,you must literally "STOMP" hard on the opposing pedal to make the other unstick and return upwards. If it makes any difference,, the pedal that sticks is the one that makes the "stick" come toward the operator. The pedal to extend the "stick" does not stick(so far).
Sounds like the spool is sticking under hydraulic pressure for some reason. We used to have a 451 (predacessor to the 166) with the same controls. Left outside pedal stick out, inside stick in, right outside pedal bucket dump, inside pedal bucket curl, right stick boom, and left stick swing. Then travel levers beside the seat. I don't remember ever having them stick, of course by the time I started running it, everything was so worn out on it that it had miles of slack. You had to practically be an octapus to get the thing on or off a trailer. My 266 has the long joystick type levers, that come out of the floor, and travel pedals.
here's the 2 machines. I still have the 266.
Well that certainly is a wacky problem you got there razerface! I would sure like to know the components of the machine. How does it "make the other pedal come up since they both can't be down at the same time"? Never seen anything quite like this problem, I curious as to what's causing it.
Since we're on the topic of Bantams here's a picture of the one I used to have before the ex made me sell it :Banghead... And coincidentally it had the same problem except on mine the pedal would get stuck in the out position... I never did get a chance to fix it... I sure wish I still had it! It was old, slow, about as worn as it gets, but had good power and best of all I got it on trade for a small load of lumber! Atco, on my machine, and I'm pretty sure it's the same on his as well, the two pedals were connected to opposite sides of a shaft so that when one went down the other would go up, and then would go back to the valve bank via a long rod. Clear as mud I hope, I'm not very good at 'splainin how things work...
Great post spitzair. "before the ex made me sell it." Now there's a phrase that'll put a burr under yer saddle! I haven't worked on any of the Ko-ring hoes, seen plenty around in my life, just haven't worked on one. That's interesting you had the same/similar problem. I wish I knew more about the components on these rigs. I want to know what is causing this.
Great pics guys, I love seeing the old Koehrings! handtpipeline, any more pics of the 266? its a gem!
yep
I will be getting greasy this week end I guess,,if the rain holds off and lets me thru the mud,,learning exactly how this all works I should know how those pedals work when I'm done. spitzair,,, were you gonna work on the spool valve to fix yours? Mine is a twin to the last pic above except I think my tracks are wider. Dirt looks same color as machine!
thanks handtpipeline!:drinkup That machine is a true beauty.
Razerface, I had planned to open it up and look to see what the problem was but it wasn't really that big an issue for me so I never got around to it... I kept thinking it was likely a broken return spring... As an aside I found a C366 during my travels last week but never got a chance to stop and take pictures of it... That's a nice machine you have there handtpipeline!
We bought the 451 new in '73, then the 266 new in '78. The 266 still looks about the same, except it's been sitting in a field for about 10 yrs, and someone vandelized the dash.
Hi razerface, I had the same problem one time but with a G1000 Gradall. It was the control valve body for the swings and the night shift mechanics said they used a wheel cylinder hone to clean up the valve body bore.
hey Dave, that could be good info,,thanks. I went out and looked for the valve. It is pretty easy to get to for working on. May put some wrenches to it this weekend. Was your bore scarred, corroded, ridged, or something else?
Ok, I just need to say this, can we get some pictures please? That would help us to understand this a bit better.
Easy now guys, be very easy with this. And I'm not saying it wasn't a proper fix for dozerdave, I'm just saying be gentle doing this. The tollerance's between a valve spool and the valve body bore is very very close. If the bore is too large, by mere thousandths, you'll have excessive internal leakage that will affect function performance and generate heat. You would only want to hone the bore if you knew for sure this was a problem. And even then...very carefully.
Hi razerface, I have no idea about the condition of the bore of the valve body as the night shift mechanic worked on it and ATCO is right. It is noplace to get carried away with the hone.
ok,ok,,, I won't attack the bore. Thanks for the warning. I plan on taking the "cone" looking things off the back of valves and cleaning whatever is in there. That is my start. Well, I think I forgot some key info,,,,The pedal only sticks at the end of travel ,,and when a load is applied . If you just move it back and forth without hitting the end of travel(stick coming toward me),,,it won't stick. Also, as we have been playing and trying to learn the machine,,,we find it seems underpowered on the hydraulics in general. As the oil warm up,,it is doesn't have the turning power it should. It won't turn with the tracks in high ,,you must shift to low to turn. We have to pick 1 end of tracks up with boom to turn them. It has 1 new track motor and 1 rebuilt . I am wondering if both problems are related. I am looking for hydraulic filters to clean or replace,,not finding any yet.
This may be a totally crazy idea, and I am clueless on Ko-ring machines. But your original post stated you operate the bucket and stick with foot pedals. In normal trench digging, you would extend the stick and bucket and drop the boom. Then, you would start to retract arm to dig trench. You raise the boom and curl/roll bucket as needed to hold grade. But the arm is just steadily being retracted. Correct? My crazy question; would the control valve for the arm retract possibly have a detent that you could select (at the very end of pedal travel) that holds the arm in retract mode while your digging? Someone tell me I'm crazy.
I don't think so. It will stick only when arm(stick) is under a load,,anywhere in it's movement arc if load applied, or at the end of movement when the cyl is at the end of travel ,,which puts a load on it. For instance,, in the middle of the arc,,,if moving in the air,,,it will not stick. If you let up on the pedal, the arm stops. In the middle of the arc,,if dropped down in the dirt and made to dig,,,when pressure is applied from dirt resistance,,,the pedal will stick and the "stick" will keep moving until the end of the stroke,,and then you must put your whole leg into the kick,,to unfreeze the pedal. That would be a real mean detent!!!
I hear ya bro. Ah, it was a crazy thought. Much like you have a crazy problem!
I have another question. Maybe nothing, but I'm curious. When you operate arm in, does the control rod pull the spool out of the valve body or does it push the spool into the valve body?
control rod is going "in" to the valve. It took 20 gal of hydraulic oil to get it up to the "low" mark on the tank. I found filters and got everything looked at and changed,,,it did not help the weak condition of the machine. There are 3 separate hyd pump systems. I assume this,,,1 digs, 1 moves tracks, 1 rotates???? What is common to all 3 pumps that would make all systems weak?
Heck, I'm out of ideas at the moment, I just don't know anything about the machine or its components. Sorry I couldn't help ya much.
weak Ive never worked on this machine, but having messed on old Drotts, that has mechanical linkage. What kind of Hyd oil are you using? Old worn machines, need thicker oil What kind of engine? Im thinking it is a Detroit 4-71, how is the fuel filters? Is the engine turning up? This has nothing to do with with the linkage, but, it could be a power issue. I would disconnect the linkage on both ends and check the binding. I am thinking those valve bodies like that, has a spring inside. Move the value in and out and see if you feel any binding. If so it could be broke and binding in the housing. Make sure a rod end is not binding. Does the shaft leak, or loose in the value body? Good Luck and keep us posted
1. 46 hyd oil 2. The engine cranks and howls,, no problem there. 3. Linkage moves easily and no sticking with engine not running. The sticking isn't mechanical,,,it's hydraulic. That valve needs to come apart,,,,,,,,,,,
Hi razerface,Your bantam is set up the same way as my Hy-Hoe with the hand & foot controls & 3 pumps.when you say "when bringing the stick in at the last of the travel ,the pedal sticks down".I am thinking you are bottoming out the cylinder and still holding the pedal down.Now this should not make the foot pedal stick under normal conditions,but if the relief valve is not opening properly on that valve body then it could cause the valve spool to stick in a kind of a "hydraulic lock".try this ,the next time this happens shut the machine off and see if the pedal returns on it's own.If that's the case,then I would try backing off the relief valve & checking pressures.
Hey 25c,, you might have missed the other explanation(sorry, my fault)where I added that it will stick anywhere on the stroke when pressure is applied. So if I drop the bucket in the dirt when the arm is halfway back,,and push the pedal to dig,,,when the arm comes back and picks up pressure from digging,,,the pedal sticks. It almost feels like,,when the sticking is starting,,that the pedal "pulls itself"down. On the other hand,,,would the relief valve stick on low pressure? This machine seems underpowered on hyd pressure on all three systems. When the oil gets hot we have to help the tracks with the boom to turn. If we were in the mud,,it probably couldn't get out by itself. On the digging hyd's,, it is weak also. I have seen the arm drop and "wait on" oil to fill cyl to get it moving again. What would affect both of these circuits?
I think you need to find that gremlin that's messing with your valve and beat the snot out of him! I do declare you have the craziest problem I've heard of. You said when the sticking begins it seems the building pressure is forcing the pedal down, never heard of anything like that. Valves just don't do that, or, ain't supposed to. I think even if the return spring was broken it wouldn't do that. Can you send a pic of the valve for us to look at?
I ran into a problem like this once on a slightly larger machine. What was happening, as the load on the main frame increased, the valve linkage was put in a bind because the frame was cracked. As the two frame pieces moved in different directions the linkage was not able to align itself as the later cable controls could and would bind until the load was removed. Actually it was a blessing, if it had been cable controls a lot more damage may have occurred before it was noticed. instead a couple hours fabricating and welding fixed the problem.
hmmm,,,,machine broken in half,,,theres a cheerful problem! Well,, I guess I'll get under there and look while my brother works the arm. I'll wait for a day he's in a good mood so we don't have an "accident" while I'm under there!!!! BillG,, don't the rules say "whoever thinks it up has to check it"..or something like that? Just kidding,,my brother likes me,,,,,,,I'll be OK.
Koehring C-166 excavator Hello...I have a Koehring C-166 excavator that I have owned for about 5 years, and has been a good machine. I use it for various jobs on my property,but it has sat for about 9 months and now the hydraulics aren't working properly. I have replaced the suction filter in the tank, double checked the fluid level and only the right track operates. The left track and all the rest of the hydraulics don't work. Can anyone give me any advise what the problem coud be? Thank you.