B21 Boom hoses leaking. Replacement

[joea99]

There I was, happily moving rocks around, when . . . Surprise . . . I noticed oil where it should not be. On the outside of the machine.

Seems one, or more, of the hoses must be leaking where they snake through the boom. Well hidden in side the "narrows" and the abrasion sleeve. I presume a crack or wear through. Matters not.

I plan on replacing all 6, I guess, since they all look about the same age, but have to question the best way to replace them. The service manual says nothing about that.

 

[lakeside]

You could try something I do when snaking flex pipe or wires.

Ask the hydraulic shop for a fitting that would connect the end of the old hose to the end of the new one. With a helper gently pushing the new hose, pull the old hose until the new one appears. The old hose acts as a guide.

You could also put electrical tape over the old to new hose connection to reduce the chance of the fitting grabbing onto a projection deep inside the machine.

 

[joea99]

You could try something I do when snaking flex pipe or wires.

Ask the hydraulic shop for a fitting that would connect the end of the old hose to the end of the new one. With a helper gently pushing the new hose, pull the old hose until the new one appears. The old hose acts as a guide.

You could also put electrical tape over the old to new hose connection to reduce the chance of the fitting grabbing onto a projection deep inside the machine.

I was just going to order the Kubota hoses. Fab price likely way over that and every time I have had some made up, they screwed up something, somehow. Too short, too long, fitting rotate 90 degrees . . .

Messicks has them in stock, so no waiting.

Fishing them through like that may be the best/easiest way as long as I do seal the ends real well.

 

[davedj1]

I just changed 3 of the 6 (one at a time) on my backhoe (woods 7500) I tied a piece of masons string to the old hose, pulled it out and cut the string, took the hose to my local NAPA and had it made, I screwed a plug on the hose, tied the string to the hose and pulled it back through. It was a little tricky but take your time and maybe even have someone help push the hose. I hit a couple snags and had to pull and push back and forth a little. I thought I was only changing one hose, turns out three of them were chafed, I'm sure the other three will get replaced soon enough. I paid about $53 each for the custom hoses.
YMMV

 

[joea99]

I just changed 3 of the 6 (one at a time) on my backhoe (woods 7500) I tied a piece of masons string to the old hose, pulled it out and cut the string, took the hose to my local NAPA and had it made, I screwed a plug on the hose, tied the string to the hose and pulled it back through. It was a little tricky but take your time and maybe even have someone help push the hose. I hit a couple snags and had to pull and push back and forth a little. I thought I was only changing one hose, turns out three of them were chafed, I'm sure the other three will get replaced soon enough. I paid about $53 each for the custom hoses.
YMMV

May try to pull all of them at once, if I can find a way to label them so the labels stay on and legible after being pulled out. Evens so, it may not be possible as they appear pretty stiff.

They all fit through a woven sleeve at the choke point and it is pretty well soaked with oil. Even with the boom fully extended I could not smooth it out too well as it's pretty slippery. Once the hoses get here and the rain stops, I will give it another look.

I got all 6 for around $250 including shipping from Messicks.

 

[davedj1]

Try using electrical zip ties, none, one, two etc etc
Or spray paint? I unhooked the hose from the valve and fed it down through the mesh sleeve out the bottom and then up the boom and out, same thing only backwards going in. Good luck. To be honest, it did cross my mind to pull all 6 at once but I would have to remove two of the rams too. Take pictures too

 

[joea99]

Well, this is turning out to be more than I had envisioned. Seems like the hoses for the boom cylinder (raise lower) run up inside the cavity so the fittings are not accessible. Of course it was the first hose I tried to replace, so, I guess that's a plus.

Looks to me like I need to remove the boom arm from the swivel/pivot so I can remove the cylinder. It's pretty much parallel to the ground now and I kind of doubt there is enough room/angle to remove the cylinder any other way. Seems that may make changing the others a bit easier as well.

I have a WSM so will look into "their way" of disconnecting the arm. I'm a little leery of just blocking it up and driving the tractor away from it.

If any of you have done this "the easy way" please let me know.

 

[eddieirvine]

find a good hydraulic shop, i have a Kubota and my brother in law works at john Deere, so they make them there right at the shop, I buy them Pizza every now and then, i pay for parts!! Seems like a good deal to me

 

[tjkubota93]

I think 1 at a time with a fitting to connect new to old like lakeside said will be easiest. Maybe not fastest, but least effort and frustration.

 

[joea99]

I already bought all 6 hoses from Messicks. Marked all the fittings where the hoses connect, at each end. I ended up having to disconnect them all, at the valve body so I could get the woven sleeve off. I did not have much confidence that I could slip the old ones out, one by one as they are quite stiff from age. Also had to drive out the pins on the arm so I could jack it up far enough to get the one cylinder out to get at the fittings.

Then the weather turned threatening earlier than forecast, so I sealed up the valve body fittings and tarped the backhoe section. When I hear thunder boomers in the distance, I head for cover. Anyway, gives me time to soak that sleeve and get it clean(er). Absolutely soaked in oil and grease. At least clean it should be easier to slip the hoses through unharmed.

 

[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.