Leaking JIC fitting

[Tacitus]

Hi there!
My boom cylinder hose fitting started to leak when I lifted the machine to widen the tracks. Takeuchi TB016. JIC fitting, not flat nose, conical 30 something degree.
It was finger tight, so I thought tightening would fix it. Well ... it leaks less, but still leaks.
The workshop that did the last service told me to change the hose.
The hose is a mile long, goes around the world and back, and I guess it's a bummer to change.
I asked if the male fitting on the cylinder needs changing and was told no (?)
So ... why do only half the job and the hardest part of the job?
If changing the hose only allegedly fixes the problem, why wouldn't replacing the male nipple only, have the same effect?
Am I missing something?

 

[doobin]

Hi there!
My boom cylinder hose fitting started to leak when I lifted the machine to widen the tracks. Takeuchi TB016. JIC fitting, not flat nose, conical 30 something degree.
It was finger tight, so I thought tightening would fix it. Well ... it leaks less, but still leaks.
The workshop that did the last service told me to change the hose.
The hose is a mile long, goes around the world and back, and I guess it's a bummer to change.
I asked if the male fitting on the cylinder needs changing and was told no (?)
So ... why do only half the job and the hardest part of the job?
If changing the hose only allegedly fixes the problem, why wouldn't replacing the male nipple only, have the same effect?
Am I missing something?

Where does it leak from? Are you sure its through the threads than around the crimp?

They rely upon an intereference fit/seal between the conical male and female bits as you tighten it. It might be worth trying changing the male bit as it's much easier- might just do the trick if it's definitely leaking from the threads not the hose crimp.

What size is the hose? I'm not aware of any possible cross-threading issues that can arise with JIC-BSP, but there are a couple of metric threads that will accept a BSP pipe being screwed on, but they'd be leaking a lot in this scenario in my opinion.

 

[Quattromike]

The hose insert can crack and leak out with the sealing face.

 

[Tacitus]

It leaks from the fitting threads. At first it was a little stream. Considering it was not tight, a light squeeze with a spanner reduced it to drops. after some more work, gave it another squeeze and now it's just wet.
At close inspection there seems to be a ring on the conical surface that is supposed to mate. I'll get a male fitting tomorrow, may be I am lucky. Changing the hose is not something I look forward doing.

 

[Gecko]

I'm not aware of any possible cross-threading issues that can arise with JIC-BSP,

It's not just the threads -JIC vs BSP have cup/cone on opposite sides, so a mating M&F thread would have either two cups or two cones.

If it's just been worked on, a crack would explain it, but I'd also be looking debris or damage on the interface surface.

 

[Tacitus]

Where is the crack likely to be Gecko?

 

[V8Druid]

I once bought a M/M adapter to connect two hose ends together ... installed and it pissed oil ... took it out and inspected it - was split from one end of the fitting to the other ... brand new out the box ... got a pic somewhere

 

[Tacitus]

Considering I just had bushes and pins changed, An this was the first job after ... but what can I say? They asked me if I bumped into something

 

[V8Druid]

Considering I just had bushes and pins changed, An this was the first job after ... but what can I say? They asked me if I bumped into something

possibly overtightened ... a cone seal only needs to be nipped enough to form the seal, not dogged solid, hanging on the spanner ... is the conical seat in the adapter or on the hose end?

 

[Tacitus]

The cone is male on the cylinder side and female on the hose.
But the hose was loose as in ,could be moved sideways by hand.

 

[Gecko]

Where is the crack likely to be Gecko?

If it's been wound up too tight, you'd expect the female (cup) to crack from being expanded.
If it's taken a hit, you'd expect it to crack where the tail meets the interface (doesn't seem to match your description).

I'd start by pulling the coupling apart and cleaning everything (threads and interface surfaces)

 

[V8Druid]

The cone is male on the cylinder side and female on the hose.
But the hose was loose as in ,could be moved sideways by hand.

????

It leaks from the fitting threads. At first it was a little stream. Considering it was not tight, a light squeeze with a spanner reduced it to drops. after some more work, gave it another squeeze and now it's just wet.
At close inspection there seems to be a ring on the conical surface that is supposed to mate. I'll get a male fitting tomorrow, may be I am lucky. Changing the hose is not something I look forward doing.

 

[Tacitus]

Actually the male is on the hose and female on the cylinder fitting.
Yes, how was it so lose that I could turn the fitting by hand, I don't know. Like I said it had just been worked on.
Today I undid the hose, cleaned the thread with brake cleaner, did it back up this time with two spanners and a bit more force, and no more leak.
Hope it holds