Blown Hose on Jinma YW-6 Hoe

[Stimw]

Had the boom lift hose blow today. The hose came out of the fitting at the cylinder. After checking it out it was only inserted about 2/3 of the way in the fitting when it was crimped.
It was about 100* today and the hoe was acting a little lazy like the hyd oil was thin which I'm sure helped but the crimp was crappy!
Tomorrow I will try to get a new sleeve on the fitting. I cut the old sleeve off of the fitting and the barb measures just under 3/8". Now if I can get a sleeve to fit over the metric hose I'll be good to go.
I will post my results.

 

[Soundguy]

Hmm.. for my money and safety.. I think I'd repalce a hose that has failed once already.. not just repair it...

good luck..

Soundguy

 

[Bob Rooks]

If you have done what I think you've done, you can use one of those steam/hydraulic bolt-through split clamps.
Or, you can use a #6 x #8 Aeroquip re-useable hose swivel end fitting with my M18x1.5 x #6 adapter.

You can see them here: Chinese Tractor Owners Association - CTOA Forums - Tractor Modifications - Hydraulic adapters

 

[Stimw]

Well the hydraulic shop put a new sleeve on the old hose and wouldn't guarranty it but they didn't charge me.
It lasted 10 seconds and popped back apart. The chinese hose barb has no real notches for the hose to grip.
They had metric end with american barb fittings to put on american hose so I went back and got a new hose made up. I've only got about a dozen more hoses left to fail!

 

[Soundguy]

Hence my previous message.. etc..

Soundguy

 

[Bob Rooks]

Well the hydraulic shop put a new sleeve on the old hose and wouldn't guarranty it but they didn't charge me.
It lasted 10 seconds and popped back apart. The chinese hose barb has no real notches for the hose to grip.
They had metric end with american barb fittings to put on american hose so I went back and got a new hose made up. I've only got about a dozen more hoses left to fail!

After reading that, I will acquiesce to Soundguy.

 

[Stimw]

As usual the new hose would not work. I had a friend PU the new hose and I went to install it and the new ends were just a tad too small for the chinese fittings.
Third trip to the hyd shop, ended up getting two JIC male fittings. Removing the ends from original hose and welding JIC to Jinma ends and installing new hose with JIC fittings.
I took a pic of the Jinma fitting split open and the original hose was only inserted 1/2 way in. I guess I can expect more of this. Also pic of homemade adatpers.
I used O/A and a coathanger to weld these.

 

[Stimw]

Well it's back to the hydraulic shop tomorrow, today I had the hose for the bucket curl burst 2" from the valve. At least I can get everything I need in one trip and just weld together some more fittings.
I have 2 relief valves in my hyd system and I've checked my pressure at 2200 psi so I'm sure it's inferior hoses. I'm guessing the Chinise used the sneaker rubber compound on my hoses. Or the additive to make the rubber last went into pet food instead!

 

[Bob Rooks]

I have 2 relief valves in my hyd system and I've checked my pressure at 2200 psi so I'm sure it's inferior hoses.

Um, I think the pressure should be set at 1,850 psig. You're working those hoses near the upper limit of their capacity.
Take a look at the adapters I made: Chinese Tractor Owners Association - CTOA Forums - Tractor Modifications - Hydraulic adapters

 

[Stimw]

Well after a closer look the second hose pulled out of the crimp. The hose was only inserted 1/2 way onto the barb again.
Looking in a hydraulics book they have 2 wire hose working pressure at 4785psi. They rate single wire at 2610 working pressure. These hoses are 2 wire so I am well within their working limits. The problem is the Chiniese don't seem to know how to assemble them.
I tried to buy an 18mm X 1.5 nut and Ace Hardware had 16mm then skipped to 20mm so I guess 18mm is not a common size. I didn't have time to chase all over town looking for them so I went ahead and welded up two more adapters and used JIC again.
Since I can order hoses pre-made from one of my suppliers (Baileynet.com )for less than half the cost of locally made hoses I think I need to get a list together and be ready for the next one to fail.