Leaking HW04 Backhoe Hose

[Smalljobs]

I've not been able to stop the leak at a hose inside the boom. It's the ORF seal where the metal tube connects to the hose leading up to the control valves. I've swapped out the O-ring a few times with no luck. I called Ronald at Ranch hand today to buy two of his adaptors that convert to JIC. My plan was to make a new hose right from the valve all the way to the cylinder. Then I learned these adaptors are no longer available.

Has anyone found a simple way to convert these Chinese hoses over to a JIC that will enable me to make up my own hoses with reusable hose fittings? I might have to weld on a JIC connection to the cylinder and another one on the fitting that is threaded into the control valve block.

Any better ideas out there?

 

[hosspuller]

When you swapped the o rings did you use the proper o rings? ORFS are a 90 durometer vs the 70 of ordinary o rings. ORFS is one of the current standard for modern hydraulics.

 

[Bob Rooks]

Is it the actual ORFS fitting, or is it a hose/crimp leak? It could also be the weld that attaches the male threads to the pipe.
Also, what has worked for me is using a soft copper or aluminum washer. It's possible that the male threads aren't concentric with the face, in which case if the soft washers don't work, you'll be welding on a JIC fitting or installing a JIC flareless fitting (if it fits the pipe).

 

[Smalljobs]

The leak is coming from the fitting itself. When I imported the BH myself I ordered and received a bag of spare o-rings. That's what I used. I've repaired it twice and it won't seal. I think the machined fitting is defective and the sealing face is not perpendicular to the the threaded diameters. I've thought about bigger o-rings, harder o-rings, etc. but that connection inside the boom (closest to tractor) is not easy to get at. That's why I want to convert it to JIC from the control valve bank to the cyliner with one hose and only one connection at each end.

 

[Smalljobs]

I have another idea and maybe Bob Rooks knows the answer. See another thread of mine here http://www.tractorbynet.com/forums/chinese-tractors/223303-hw04x-bh-hose-connection-problem-2.html. It shows photos on page 2 where I used two of Ronald's adaptors on the backhoe control valve block. One of those adaptors was used to simply run the return-to-tank line into a Zing filter and then back to tank. I think there is almost no pressure in that line? I can put the original Chinese hose back on that return right from the valve block up to the filter. Then I could cut off the Chinese hose end and just use a barbed fitting and hose clamps at the filter inlet. Will that work?

After that I can use my newly freed up nifty adaptor and convert the troublesome leaking line to 3/8" JIC right at the control valve block. From there I can run a new line all the way out inside the boom to reach that outer most cylinder, thereby eliminating the troublesome metal tube joint inside the boom. At the cylinder we will weld on a male JIC connection.

 

[Bob Rooks]

I have another idea and maybe Bob Rooks knows the answer. See another thread of mine here http://www.tractorbynet.com/forums/chinese-tractors/223303-hw04x-bh-hose-connection-problem-2.html. It shows photos on page 2 where I used two of Ronald's adaptors on the backhoe control valve block. One of those adaptors was used to simply run the return-to-tank line into a Zing filter and then back to tank. I think there is almost no pressure in that line? I can put the original Chinese hose back on that return right from the valve block up to the filter. Then I could cut off the Chinese hose end and just use a barbed fitting and hose clamps at the filter inlet. Will that work?

After that I can use my newly freed up nifty adaptor and convert the troublesome leaking line to 3/8" JIC right at the control valve block. From there I can run a new line all the way out inside the boom to reach that outer most cylinder, thereby eliminating the troublesome metal tube joint inside the boom. At the cylinder we will weld on a male JIC connection.

Perfect. There should be no back pressure at all downstream of any return filter except for the static head in the reservoir. Go for it. :thumbsup:

 

[Smalljobs]

Bob,
Sounds good and will go ahead. I'll post pictures of the revamped connection at the cylinder. Looking back, I'm in the import business and spend 6-8 weeks/year in China so I imported the BH myself direct from the factory. This HW04 BH had so many defects, factory screw ups, etc. that I often wonder how anyone could make any $ on these. I bought it cheap and knew in advance of what to expect.

After I fix this hose problem and replace seals in one swing cylinder, I should be all set with a 7 ft frame mounted BH, complete with Bro-Tek thumb.

Bob...Thank you.

 

[Smalljobs]

All leaks are solved for the first time ever with this BH. It leaked right from the factory.

Here's how we converted the ORFS to JIC at the cylinder: I removed the old hose and cut off the swaged end in such a way that I could salvage the internal barb that contains the integral nut, ORFS, etc. Then we welded on a 3/8" JIC male allowing me to use reusable hose ends and make up my own hose. I ran the new hose from the boom cylinder all the way to the control valve block.

One of the swing cylinders was also leaking badly. A piece of cotter pin from the piston castle nut had fallen off and scored the entire cylinder. Fortunately, it could be re-honed and saved.

I have one last problem and hope someone can help me. One of the swing cylinders will not develop full pressure. The PRV is set around 2,000 psi and I have a gage on it. I'll be working the hoe and all is fine with the PRV occasionally howling. Once in a while only the left swing cylinder will be weak and my gage will show roughly 1,000 psi. I suspect the control valve is not fully diverting full hydraulic power. Am I right? Can I disassemble and repair it?