lower pin for hydraulic cylinder on bucket arm nearest cab - won't extract

[cjdgeorge]

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?

 

[Delmer]

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.

 

[Welder Dave]

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.

 

[cjdgeorge]

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

 

[cjdgeorge]

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.

 

[Delmer]

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)

 

[cjdgeorge]

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

 

[Bls repair]

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 .

 

[DMiller]

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.

 

[donkey doctor]

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.

 

[cjdgeorge]

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

 

[Nige]

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..?

 

[DMiller]

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.

 

[Delmer]

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.

 

[Welder Dave]

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

 

[DMiller]

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.

 

[Tinkerer]

If it's an e27z here is the pin image.

 

[Nige]

Tink, Do you have anything showing the hydraulic lines so that the OP can understand how that fitting should be disassembled..?

 

[Bls repair]

Here is an example of one type

 

[Tinkerer]

Tink, Do you have anything showing the hydraulic lines so that the OP can understand how that fitting should be disassembled..?

Left click once on the image to enlarge it.