Afternoon All, Newbie here. Just hired a Bobcat 2.75 Tonne E272 for a week last Monday and moving in some woodland to clear it of bamboo, a bamboo stick about 15-20 mm in diameter got caught in the hydraulic pipes and pulled/ pushed(?) the projecting threaded pipe coming out of the barrel at its lower end sideways and out spurts the hydraulic oil! There is a crack about 15 mm long. Managed to get off the top pin easily - just took out the circlip and out it came. There are two pins in the bottom bracket (upper and lower) and the upper slides in and out no problem. BUT.. the bottom one I can only get to move about 1 mm in either direction. I need the cylinder off to try to weld up the crack. Have tried: releasing agent, nylon hammer and drift, club hammer and chunk of wood, sledge hammer and wood then sledge hammer direct! No joy. I even considered (even though all sense said that it was impossibly unlikely) considering undoing the grease nipple in case the thread had been over extended into the pin and was restricting its movement but then discounted it. Am now considering a blow lamp on the housing to expand it and release any restricting gunge. Questions: IS there any hidden form of restriction such as a grub screw? Is there a preferred side of it to come out? the threaded rod/bolt stop side (left as you sit in the cab) or the other way? It seems to me that the connection pipe off the cylinder "should" rightly be a threaded connection but for the life of me it looks as if it is all one piece and sensible use of a spanner to try and "unscrew" it shows it does not think of budging. Does anyone know if this is a one piece item of the thread is so well hidden that one cannot see it? Any other suggestions?
Is the 15mm crack that's leaking the copper colored crack on the fitting joint in the first two pics? Don't weld it, and don't try to get that cylinder off. Did you use a box end wrench/spanner on that fitting, or an adjustable wrench? you'll need a six point socket or box end on the top of that fitting, or a flare wrench for the hex on the base of that fitting.
Do you mean hired or rented? If you rented the machine you're better off to call the place you rented it from and let them fix it. If you do something that causes more damage or contamination you'll be on the hook.
To Delmer Senior Member No form of spanner at all used on the fitting (by which I am assuming you mean the copper coloured cracked "pipe" to which the hydraulic hose is attached by a threaded connector); It seemed too risky. I could see no thread between the pipe and the cylinder of the main arm hydraulic drive. I HATE adjustables and will only use them in extremis. We used plumbers' grips to undo the flexible pipes which have been connected one to the other to get the Bobcat moved out of the way to a work location. What we "think" we need to get off is the black tube containing both the hexagonal bolt like obuect on the left of the photo and the silver metallic nipple for the hose which has been knocked sideways revealing what looks like a copper inside. It "was" that crack we were proposing to weld and have been advised not to. We want to take off the whole arm to be able to get it all in a workshop and it is the pivot pin that we cannot get to budge more than a mm in and out
To Dave Welder We hired it! I wont say from whom but they have now shut down on Tues Wed till April 14th! It would be great if we had the machine working but need to fix it ourselves. It cost me a fortune (over 15% of the hire fee) to have it insured so sod that for a lark if it gets damaged in our effort to get it going. We have already had to put on a track that was not properly tight when we got it and it came off which took several hours and not a little special grease for the wheel adjuster! I will risk being on the hook as they have not replied to our emergency call and we had to pay for someone to fix the track and supply the grease.
Don't take the cylinder off, no need to. That fitting should come off easy enough. I'm with Dave. Assuming you're in the UK Oxford, doesn't the "rental company" or whatever you call it take care of this sort of thing? Here we would have to pay extra for insurance, or pay for the damage, but if you send them these pictures, they can probably get you a new fitting, and it won't be bad compared to what could go wrong. edit: I see you posted just before I did. If they're not available, and you have no other bobcat or hydraulic shops available, take a socket to the top of that fitting, clean it PERFECTLY, like flammable brake cleaner then blow it completely dry, then bend it back into shape, then braze (or solder) that fitting again. You can't see any threads because this joint is sealed with o rings or metal washers, not Pipe thread, (or BPST)
Brilliant Now that all makes sense. The photo is here just for posterity. We have access to some Oxy for brazing down at the farm locally BUT I still need to get the b***** of to bring it down to the farm so back to the first question... How to get the lower pin out? You say not to take the pin out but how does that fitting come off? left hand thread? WHERE is the thread? Not sure if the PDF uploaded will work
It looks like a swivel fitting to these old eyes . If it is you will have to take it apart so you don’t burn out the seals .
We called these 'Banjo' fittings, will be a nipple internally threaded on the cylinder, the outer piece is a barrel with the tapered flare fitting in it and NO do NOT weld that. Look to a Hydraulics shop for a replacement fitting as will no longer swivel, may never seal if weld it.
Type banjo fitting into google images. Lots of pics there to show how it goes together. You can figure out from there where it comes apart. d.d.
A better photo Still unsure what to unscrew from what or where... There is a nut/ heagonal end / bolt (not sure what but would guess it is the shaped end of a solid tube and to be used to turn it -) on the the end An inverted "Tee" shaped two tubes one part broken a flange with the main cylinder doing the work Where is the thread to undo it IF the hexagonal shape really IS a means of unscrewing this tube then a suitable ring spanner should do it and I assume it is conventional turn left to undo Once that is done, the problem will be getting a spare part with the country locked down Any ideas of a supplier in Oxford? or who can post? Any ideas of a temporary fix? Will the two parts of the T come apart and perhaps be fitted with PTFE tape from the INSIDE so the pressure pushes the tape into the crack? Just grasping at straws for the weekend Chris
A bit late in the game but better later than never.....!! That's a banjo fitting as the boys have stated above. An open-end "holding" spanner on the hexagon where the red arrow points. You might have to grind one down thickness-wise to allow it to fit. A ring spanner or socket on the blue arrow. Hold the open-ender and swing on the ring, and off she comes....... PTFE tape on a hydraulic system. You're havin' a larf aren't you..?
These are Silver soldered on a Sweat Fit(Snug to tight and pressed together) the only way to fix one that has been Expanded is replace it.
You've tried everything you have on that pin. It's stuck in the end of the cylinder, and it might have to be pushed out with a porta power hydraulic jack, or burned out. No reason to remove the pin, it's a rental, it's not like you have to deal with this again. If you can't get the fitting, I wouldn't hesitate to braze, or solder this. If you try JBweld, you'll have to get some on the inside of the fitting to seal the crack, it will never seal from the outside with epoxy, apply suction to the inside to suck the JBweld through the crack enough to form a small bulge on the inside. Your taking a chance that breaks off and goes somewhere in the system you don't want it to go.
You may need something like this or a flare nut wrench. I don't think that fitting is repairable and it may be the pic. but the flare itself doesn't look too good. Putting any heat to it is going to draw oil to it Click on the secure-grip tight clearance offset sockets. https://www.mcmaster.com/hydraulic-wrenches
There are seals inside the tube region where the flare connection is, heat that and you chance destroying those, would have to be Off to silver solder or weld, where is was silvered originally good luck getting a weld to stick.
If it's an e27z here is the pin image.
Tink, Do you have anything showing the hydraulic lines so that the OP can understand how that fitting should be disassembled..?
Here is an example of one type
Left click once on the image to enlarge it.
OK guys REALLY appreciate the input. I just have to get this machine fixed one way or the other as I am going stir crazy with all this work due to be done (yes isolated in woodland with only the two old gits her both over 70 but keen to get on with it) and the supplier shop shutting up till mid April - and here was I thinking I had got 2 weeks extra hire! So took some better photos and put on thinking cap. This is the inside with the cap (not bolt - not banjo - just an end cap) taken off and showing a circular (not hex) "connection/join" with the main cylinder This is the end cap You can see the copper break just visible having straightened it somewhat from say 12 degree angle to about 5 degrees off perpendicular From the side sorry about the focus Internal view To my uneducated eye it looks like either a press fit in the factory or One piece with the main cylinder which would be a mindless design (you never know!) anyway it looks like a specialist repair with special tools or brazing and soldering Given its location at the end of the garden 100 from the house, it looks as if it is necessary to get that bloody pin out so I will turn to that whilst others digest this new non-banjo info Chris with appreciation to all those contributing and apologies for the photos
You did remove #13 right ?
Absolutely, may be a 73 year old git past his prime but was taking motorbikes apart and making combos back in the early 1960s with a chap who raced bikes called Ernie Barratt. I even checked the grease nipple knowing it was not even remotely likely to be intruding. Next plan is a blow lamp. That (and the PTFE) shows how desperate I am! This exploded diagram is MOST helpufl
I hope I didn't offend you with my question. We never know the abilities of people that come to HEF for help. Some of them should be arrested for even picking up a wrench.
Looks like what appeared at first sight to be a banjo bolt that the bottom end of the banjo part might well be friction-welded to the cylinder barrel. It's the most likely way I could see it being attached looking at the photos. Try soaking around the pin in penetrating oil and leave it for a while. Repeat and beat with FBH as required to keep moving the pin back and forth the little bit it will move at the moment to let the penetrating fluid do its job.
I still think this fitting is like the diagram in post #19, it looks like the threads go all the way through that center section of the fitting, and there should be a seal and threads on the piece that is welded to the cylinder. Did you try to unscrew the fitting in question? with a pipe wrench(plumbing spanner?) It's obviously not a standard banjo fitting where the bolt goes through the fitting, but looks like you could unscrew that fitting, flip it over and put it right back in place (not accomplishing anything, except maybe changing the "clock" of the fitting). I think, there's still a seal in there, plus you'll need to get ALL the oil off that fitting to have any chance of soldering/brazing it. you tell me what the inside of that fitting looks like, you've got a better view of it. I was sure from that first picture that you had a hex fitting against the cylinder, oops.
I understand your logic. The design seems very unusual to say the least. But if it was screwed into the cylinder barrel wouldn't it be shown as a separate part on the exploded diagram..? See snip below. The fitting on the other end of the barrel is shown the same way, the only separate parts are the plug and the O-Ring. I'm still thinking it's most likely to be friction-welded to the barrel. A look down the hole ought to confirm that.
I've never seen one like this, so just guessing. Maybe the collar is welded to the cylinder, and the fitting with short nipple is brazed into that short collar on the cylinder. It also looks in some of the pictures like what I'm calling a banjo fitting isn't symetrical, it's got more fitting above the tee than below the tee, but that could be the way it looks with the bend? Best way to tell will be inside the fitting, it should be easy enough to tell if the threads end, or are threaded onto another threaded piece. edit: I can't tell what I'm seeing in the pictures, one looks like the threads end, another looks like the threads might continue under the end of an inner piece, and it looks like the bottom of the port could be blocked just like the top of the port will be by the plug protruding into the center of the outlet to the side of that fitting. Need to see it in person.
I'd bet money that if it's one piece and friction welded to the cylinder it'll be manufactured complete, threads & all, and simply spun up to red-hot on the FW machine and given a hydraulic shove to "glue" it to the cylinder barrel.
When you move cylinder does the pin move with it?
I think Nige is correct. I have seen this style on an older piece of equipment. I have also seen the fitting welded in place. Have even seen the welded style leak at the welds. Do you think he could cut this fitting off (after dissembling and cleaning) and tap for a standard pipe thread fitting, screw the fitting in, then weld. Would have to make sure it didnt protrude into the cylinder, if the seal passes that point.
On a rented machine..? I don't think I'd be up for taking that chance.
If it's not threaded and screwed on, then there's no seal left inside, and you could try to solder/braze that fitting again in place. Then it would be fixed back to original condition, it "might" get a little dusty in the next couple weeks, get forgotten about accidentally, if it fails down the road who's going to remember? I wouldn't mess with modifying something permanent on a rental, though if they see this, would they try to fix the fitting or scrap the whole cylinder? There's not going to be a replacement cylinder available with the shut down, so what good does it do to get the pin out?
I think he wants to take it where his tools are .
From the sound of it I get the impression that it was not possible to get gas bottles to the machine location, therefore the cylinder had to come off in order to get it to the gas bottles. IIRC I heard the word “farm” mentioned.
No offence at all Tinkerer. Just very grateful. After all I am the idiot that thought I might be able to block it with PTFE from the inside
The cylinder is totally loose on the pin
The location The loose cylinder The bamboos that caused it!!
A bit of heat and liberal applications of the FBH called for then.
yea, kinda slipped my mind that it was rented...If it were his, maybe.
There is a very slim chance the pin has some taper and you are beating it the wrong way. The machine looks to new for a pin to be seized that badly in the mounting ears. The problem with pounding on the keeper pin end is that the pin will swell badly. Then you will have to maybe saw the pin off on both sides.
I will get the vernier out this AM . Crude estimation with a rule indicates it is the same. It travels such that receptor hole for lock bolt goes inwards, i. e. As you are in cab l to r. I can then be put back in place. Looked up in google what FBH stood for and had a big “larf” and can confirm it was very F big - a sledge So heat next.
I think there is a slim to no chance the pin is tapered. But, there are situations anything is possible. Be careful to NOT set yourself up for a financial rape from the owner of the machine when they see the burnt paint and beat up pin.
36 mm both ends give or take a burr or two Left side from inside cab Right side The side I have been whalloping so a bit burred the most movement I can get is about 0.5 or 1.0 mm The industrial blowlamp is a bit like throwing a banana down Royal Avenue as they say in Belfast Chris
I wonder if the pin could be made out of, shall we say, "less than optimum quality material", and has now adopted a similar shape to the aforementioned banana..? That'd make it stick and assuming that is the case only a gas axe or an exothermic lance is going to get it out. Either way the pin will not survive.
Perfect; a straight pin. Looks like the pin is starting to mushroom from the pounding on it. I don't know what an industrial blow torch is in the UK. In the US we use an oxygen/ acetylene powered torch with a rosebud tip. I guarantee it would heat both of those ears. Below this is what I would have a helper hold against the pin to prevent further mushrooming it. Safety glasses are an absolute must have. I had an eye punctured once in a situation similar to what you have. Hit hard and hit it squarely!
For what it's worth... never hit the pin directly!!!! always use a drift, punch, smaller pin, pipe,etc.... once you start mushrooming the ends you're in for a time of it!!!
Do you have access to something like this to try and press it out?
Is the pin locking bolt hole clear? Grind the mushroomed part of the pin off.
Done or tried all those helpful suggestions... Rang a Bobcat agent who WAS open... Nearest was Peterborough REally helpful. Answers: the only way to fix the bent threaded tube is to go to an hydraulic specialist with the whole ram and they fix it in a workshop. The only way to get the pin out is to ply pin ping pong There and back till it loosens. If push comes to shove they take the whole arm off and put it in a press. We have tried all the above options but are not considering welding up a frame and using a car bottle jack More later!
(popcorn eating emote here....again)
Pretty good rental, huh? " a one week hire, a one week hire" (sung to the tune of "three hour tour")
Please keep posting your progress. You have a situation we've seen on HEF many times, and on our own machines.
My only worry is that the pin is slightly bent and that although at this moment it will move a little to & fro that’s the most your going to get out of it and it won’t come out without surgery.
Took advice on the car bottle jack as I thought this was hopeful. Apparently it does work if the jack can lift 80 tons! My super engineer mate came up with the idea of welding on a nut and bashing that to get it going in more and to avoid burring end. In the what has got it shifted to 50 mm± was a electric H breaker with a socket on the end. Cant post a video on this forum but will try to send a link. Upshot is that the Peterborough firm RTC who were brilliant recommended Dave Whitby who does serious hydraulics and a chat with him was most illuminating. Apparently he has to fix hundreds of these Bobcat fixings as they are so weak. His solution is to cut out the original and weld a proper steel fixing in place - once done they never come back.... More to the point he has a delivery due next Wed about 5 miles from me and can pick it up and turn it around in 24 hours. AND he can supply a new pin with it as it is likely that this one will have to be cut out. More later..
Fantastic idea on the breaker! If it would have been me it would have happened when the machine is in the deepest mud hole surrounded by tree's that you couldn't get to it easily.
It WAS the two pipes were joined as a bypass to get the effing thing out to the lawn!
Good you could get it moved to an open area.
Now the pin has moved in one direction can you get some lubricant on the exposed end and drive it back in the other direction..? Repeat back and forth as required until it finally moves far enough to get the cylinder out. You don't have to get the pin all the way out, although it might pay you to, then assault it with a decent angle grinder (the one lying on the floor by the welder will do the trick) and take a few thou off the pin so that it goes back in easier than it came out .......... Breakers are severely underrated. Nice job whoever thought of that.
Awesome ! Very creative to weld the socket on to hold the bit in place !
Might as well put some lube in the hole on the side you drove it out from before you drive it back. Never seize would be good if available. d.d.
A friend of mine tried the breaker thing and had his pin so mushroomed afterwards it was like the pin was part of the casting ending up torching that one out.... the tricky part is isolating the impacts so they do not swell the pin.... this is where you really need a second smaller pin pushing tight on the stuck pin before any impacting takes place!!! If you are going to try to 'ping pong' the pin I would sand/grind the exposed end of the pin down a few thou. then lube it up also anti seize the bore on the other side. Since you mentioned replacing the pin anyways
If the pin is soft enough to drill drilling holes near the outside edge of pin should relieve some pressure on it,making it easier move
Cutting torch! Works every time.
Personally I'd go for an exothermic torch and carve lengthwise right through the middle of the fecker. That's exactly what those torches were designed for. It'd fall out then........!!
All most everyone has a drill
You don't want to make it too noticeable on a rental machine or it could cost you a bunch.
Why is a rental machine being worked on by a customer anyway?
Because the rental place is closed due to the virus.
If we are going to replace the pin, how about sawzall either side of the cylinder and take it out...I read earlier that the pin is free in the cylinder eye. Then, put a porta power in the center (they can be rented very inexpensively), and push. One side will move first. Once it is out, you have a clean shot for a drift with a holder and another person with the BFH (technical term). No mess from heating, and the cylinder is out so you can take care of having it fixed while you get the rest of the pin out. Just a thought, and shouldn't be a problem getting those tools to a remote place.