B21 Boom hoses leaking. Replacement

[joea99]

So, since Kubota threw a curve by changing some of the hose fittings flare nuts to 24mm/1 inch, and having to order a crows foot of that size, figured I would ask another question. Since I have never tightened this sort of "high pressure" hydraulics before and the boom cylinder is up inside a cavity, I figured I would use a torque wrench per factory specs.

On to the questions. Some of the fluid dripping out of the old hoses and cylinder fittings seems a bit cloudy/milky. I did change the fluid and filters about 10 hours back, or so. Should I be concerned? If so, what is the best thing to do?

Might as well ask if the backhoe lines are "self venting" to get the air out of the hoses and fill cylinders (repeated cycling?) or will I be pulling my hair out trying to vent them?

 

[davedj1]

I'm no expert but on my fittings (JC6) you could tell when they were tight. Kind of like squishing something, then solid.
My experience has been with bleeding the hoses, yes, repeated cycling will do it.

 

[tjkubota93]

So, since Kubota threw a curve by changing some of the hose fittings flare nuts to 24mm/1 inch, and having to order a crows foot of that size, figured I would ask another question. Since I have never tightened this sort of "high pressure" hydraulics before and the boom cylinder is up inside a cavity, I figured I would use a torque wrench per factory specs.

On to the questions. Some of the fluid dripping out of the old hoses and cylinder fittings seems a bit cloudy/milky. I did change the fluid and filters about 10 hours back, or so. Should I be concerned? If so, what is the best thing to do?

Might as well ask if the backhoe lines are "self venting" to get the air out of the hoses and fill cylinders (repeated cycling?) or will I be pulling my hair out trying to vent them?

It should bleed out itself by cycling like he said.

Certain hydraulic fittings will tell you how many flats to turn past snug. (1 flat= 1/6 turn) if you want by spec.

You can tell when it gets tight though.

 

[joea99]

The WSM has some torque specs. Since I already sprang for a cheap crow foot set, I may as well hold off.

So, I should not be concerned about the look of the fluid? I'm not, really, just wondering if I should be. May just be optical delusions anyway.

 

[davedj1]

I would flush the cylinders out before I put the new hoses on, you definitely don't want water in the system. Can you work the cylinders manually since you have them out? Does you hoe have it's own pump? I would be nervous to contaminate my whole system.

 

[joea99]

I would flush the cylinders out before I put the new hoses on, you definitely don't want water in the system. Can you work the cylinders manually since you have them out? Does you hoe have it's own pump? I would be nervous to contaminate my whole system.

Same fluid for hydro drive and cylinders. I've got maybe 50 hours since fluid and filters changed. I checked it periodically and did not see any change in the clarity on what I saw on the dip stick.

I only have the one cylinder out and it put up a fight when I kinda, sorta, tried to pull the ram in. Seems like it could be quite a struggle to do it manually, especially working alone most of the time. I suppose I could just "tip" this one and let it drain out. Certainly don't see a practical way to actively flush them out, unless I attempted to operate them under pressure with the "venting" side open. Even so it would be messy, if not dangerous.

 

[tjkubota93]

Is there any reason to believe the fluid is dirty or wet?

If not, just put it together. You can change fluid and filter if needed.

 

[joea99]

The fluid that dripped out might have looked a bit cloudy.

 

[tjkubota93]

Sounds like it all needs changed. That fluid came from the tractor right?

 

[joea99]

As mentioned earlier, less than 50 hours on fluid and filters changed.