Hydraulic hose problem

[GNB]

I have a problem with my Kubota B 2410 HST , it has a loader on it
I bought the tractor 2 weeks ago used of course and it has blown 3 hoses
on it, I change one and it blows another at the loader control stick, I am
new to tractors so do not know why it is blowing these hoses, today when
I went to get a new hose built the guy said that it maybe that the pump
is hooked up wrong, it just blew a small hose right behind the loader, hope
someone can help..
Thanks
BNG

 

[J_J]

Check your pressure with a 3000 psi gage.

New hoses are tested to at least double or triple the printed psi.

I think you just have some old hoses, sun dried and cracked casing allowing the wire to rust, etc.

 

[GNB]

Thanks I will check the psi
maybe I should just replace all the hoses only have 7 more to go...

 

[Discount Hydraulic Hose]

Check your pressure with a 3000 psi gage.

New hoses are tested to at least double or triple the printed psi.

I think you just have some old hoses, sun dried and cracked casing allowing the wire to rust, etc.

The news is even better than that. The ratio of minimum burst pressure to maximum working pressure is 4:1, so if your hose has 3,000 PSI on the layline, then it's been tested and proven not to burst at less than 12,000 PSI.

The only exception to this that I have encountered is hydraulic jack hose, which is rated for 10,000 PSI at NO IMPULSE. The NO IMPULSE is important, and the minimum burst pressure on those hoses is 20,000 PSI (a 2:1 safety factor, which they can get away with because there are no impulses in this application.

The OP, replacing all of the hoses may be the way to go here. If all of them are old and worn, then replacing just one or a few is only going to lead to the eventual failure of the others.

 

[rswyan]

I think you just have some old hoses, sun dried and cracked casing allowing the wire to rust, etc.

I have a B2910, possibly of similar vintage ... and I've got one loader hose that has started to split right at the QD at control valve ... so I'd say your assessment is entirely reasonable :thumbsup:

 

[J_J]

Have you checked the hose supply at.

Surplus Center

Hose and Tubing

 

[tcreeley]

I just bought a hose and fittings to replace a blown hose on my NH 7308 loader. I measured what was there and it looked like either a 7/8 wrench or a 22mm wrench. Seeing the tractor was a Shibaura made TC30, I got two craftsman 22mm wrenches. They were so tight I had to tap them on to use them. When I bought the hose, I picked up a couple of 7/8 wrenches. The fit is sloppy. There doesn't seem to be a middle ground. Somebody wasn't machining to specs. Anybody else running into this?
Tractor supply is not the place to buy hydraulic fittings- out of stock and staff are clueless. Now I figured out what I need, I can buy online.
Like the op is experiencing- one hose goes, the others are already lined up for their turn!
On the adapter's female pipe thread side, where it screws on to the hose's male pipe thread end- leave it dry? teflon? dope?
I always leave them dry- but I thought I would double check.

I am thinking of taking a grinder to the 22mm wrenches to improve the fit.

 

[J_J]

You need some kind of thread sealer on NPT fittings.

http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

 

[CJONE]

I just bought a hose and fittings to replace a blown hose on my NH 7308 loader. I measured what was there and it looked like either a 7/8 wrench or a 22mm wrench. Seeing the tractor was a Shibaura made TC30, I got two craftsman 22mm wrenches. They were so tight I had to tap them on to use them. When I bought the hose, I picked up a couple of 7/8 wrenches. The fit is sloppy. There doesn't seem to be a middle ground. Somebody wasn't machining to specs. Anybody else running into this?
Tractor supply is not the place to buy hydraulic fittings- out of stock and staff are clueless. Now I figured out what I need, I can buy online.
Like the op is experiencing- one hose goes, the others are already lined up for their turn!
On the adapter's female pipe thread side, where it screws on to the hose's male pipe thread end- leave it dry? teflon? dope?
I always leave them dry- but I thought I would double check.

I am thinking of taking a grinder to the 22mm wrenches to improve the fit.

I have a lot of customers try to tell me line size by what wrench they used. different manufactures use different size wrench hexes and now that the cheap import suppliers are getting into the game it is getting even worse. The problems you are having is directly related to no quality on the manufacturers end. If it truly is NPT then use a good PTFE high pressure sealant on the male thread. CJ

 

[tcreeley]

I got some sealer, put the ends on the hose with sealer, then put it on the tractor. The flare ends were fine, no leak. The pipe thread connection for the hose both leaked. I've used teflon and stick dope with with brass and copper in the past- used it right away and never a leak. Do you have to let these sealers cure before you put them under pressure by turning the tractor on? Had real slow drip -you could count to 10 between the drops. I kept tightening it, but no luck.

 

[J_J]

http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

 

[tcreeley]

http://www.henkelna.com/us/content_data/316041_FINAL_LT4680_AAM_Do_It_Guide_v7.pdf

 

[tcreeley]

Of course the slow drip was there this morning, after using thread sealer paste. I went to my backup hose and fittings I bought (for when the next hose blows!) and this time I used plain old PTFE teflon tape. I used 21/2 wraps and kept it back up from the first two threads on the male end of the hose, and I screwed on the adapter. Finger tight, grip tight (wrench), and then a little extra. I pulled the new leaky hose off and put this one on - no leaks. I can live with that! Pics are taken after I ran the tractor.
View attachment 385763View attachment 385764 - my 22mm, 3/4, 7/8 wrenches! View attachment 385765
Re specs on wrenches and fittings, I found that of the two same Chinese made adapters, one worked with the 22mm, the other worked with the 7/8. We are back to the good old days when we used to joke about it being made in Hong Kong. Hard to know what to expect. As long as it works, that's what we can hope for.

 

[Discount Hydraulic Hose]

You need some kind of thread sealer on NPT fittings.

http://www.henkelna.com/us/content_data/141299_LT5557_5452SSF448695.pdf

If he's buying hydraulic fittings, they are most likely NPTF, and not NPT

I'm starting my own online campaign to get more people to use the correct term. NPTF (National Pipe Taper Fuel) is a tighter fitting, dryseal version of NPT. The general thread dimension are the same, but the threads are designed to fit more tightly together. Technically, this connection doesn't need sealant (the first time), but one you have tightened the fittings the threads become deformed, so anytime you disassemble a connection and reassemble it again, sealant will be needed.

Almost everyone I know uses sealant the first time and every time, just to be sure.

 

[J_J]

NPT verses NTPF

NPT Vs. NPTF Taper Pipe Threads

 

[CJONE]

Almost everyone I know uses sealant the first time and every time, just to be sure.[/QUOTE]



And a lot of times with just sealant they will still leak. That's why I use both dope then tape. CJ

 

[Threepoint]

If he's buying hydraulic fittings, they are most likely NPTF, and not NPT

I'm starting my own online campaign to get more people to use the correct term. NPTF (National Pipe Taper Fuel) is a tighter fitting, dryseal version of NPT. The general thread dimension are the same, but the threads are designed to fit more tightly together. Technically, this connection doesn't need sealant (the first time), but one you have tightened the fittings the threads become deformed, so anytime you disassemble a connection and reassemble it again, sealant will be needed.

Almost everyone I know uses sealant the first time and every time, just to be sure.

Out of curiosity I just checked Tractor Supply Company's website for hydraulic fittings, and hoses with factory ends. All of them, from 4000 psi down, are listed as NPT. I'm assuming they are, in fact, only NPT and not NPTF, but I don't know. If the distinction was lost when the descriptions were written, that would be a pretty big error.

 

[J_J]

Another point of interest would be that NPT fittings were never designed to be used over and over as there is some compression and distortion every you tighten the fittings.

That includes the NPT crimped on hose fittings. So if you notice them leaking, you can try tighten them down and use paste or replace them.

If y use anything like a lubricant, the torque figures will not be correct.

Torque figures are for dry contact.

So what happens if you mix the two type threads?

Is each fitting identified as to the NPT or NPTF?

OK, who started this bag of worms.

No wonder the NPT stuff is leaking more, we don't even know what we have.

Now that the threads are mixed/combined and tighten, what do you call the mixed up threads now? What a bunch of crap.

 

[CJONE]

Another point of interest would be that NPT fittings were never designed to be used over and over as there is some compression and distortion every you tighten the fittings.

That includes the NPT crimped on hose fittings. So if you notice them leaking, you can try tighten them down and use paste or replace them.

If y use anything like a lubricant, the torque figures will not be correct.

Torque figures are for dry contact.

So what happens if you mix the two type threads?

Is each fitting identified as to the NPT or NPTF?

OK, who started this bag of worms.

No wonder the NPT stuff is leaking more, we don't even know what we have.

Now that the threads are mixed/combined and tighten, what do you call the mixed up threads now? What a bunch of crap.

+1 completely agree. Just like everything else, it is getting so messed up you can't accomplish anything without a bunch of grief. CJ

 

[SPYDERLK]

Another point of interest would be that NPT fittings were never designed to be used over and over as there is some compression and distortion every you tighten the fittings.

I find NPT fittings to get better with use, esp if used with sealer repeatedly in the same hole. I believe many taper threads arent quite round off the production line due to the cutting flutes on taps or dies used to cut the threads. The worst ones are difficult to seal and need to be burnished in to the mate. A problem fitting set can often be corrected by using anti seize in the joint and tightening moderately -- and then rotate back and forth from this position ~1/8 turn several times. Disassemble, clean, and reassemble using tape or sealer.