Any of the hydraulic hose experts seen anything like this ?

[riprap]

I posted a problem I am having with the hoses on my Kubota BH75 over in the owning/operating area. - This post explains my findings with some pictures -

http://www.tractorbynet.com/forums/...ng/220160-bh75-hoses-popin-2.html#post2529325

My question is - since the hoses are practically new from a usage standpoint (less than 10hrs) and the corrosion is fairly widespread on the failed hoses (now up to 8 hoses, 3 circuits) - has anyone seen this before ? -

Is it likely that the corrosion is from the inside due to some type of moisture build up in storage - or is it from the outside. Or is it some type of manufacturing defect ? The storage, while in an unheated shed, was dry, the hoe itself looks basically brand new, there is no rust on it or any of the connections, bolts, etc. So I have a hard time thinking it is environmental.

I certainly don't want to have this happen again, but I don't see anything that could be done differently (other than using it on a regular basis)?

The hoses are the typical Anchor Coupling Inc. 100R17 type Kubota uses on their hoes, the hydraulic fluid is that used on new delivered Kubotas - I think they start with SUDT synthetic ?

 

[J_J]

That looks normal for a hose that has been rubbing on something. When the rubber cover is exposed, rust will set in and the hose will eventually burst.

I see nothing unusual.

To solve something like that, or prevent it from happening, the hose should be secured, or have an external sheath on the hose like this.

SNT-Group | Safeplast Hose Protectors

Hose Protection > Discount Hydraulic Hose.com

Motion Industries - Product Search -- Parametric: HYDRAULIC HOSE: PROTECTION PRODUCTS

 

[riprap]

That looks normal for a hose that has been rubbing on something. When the rubber cover is exposed, rust will set in and the hose will eventually burst.

J_J, the pictures of the exposed braid were where I cut the cover away - there is no damage or even a scratch on the hose cover where these corrosion bubbles are formed. The hoses failed in places that do not touch anything.

 

[J_J]

riprap, You said this.

[ These hoses have a 12,000psi burst pressure - to have 5 blow out on very light use is impossible - hence it is clear that the problem is corrosion. ]

You have to be assuming this, that the people that built the hoses follow USA standards in hose specs.

I would think inferior hose, and not to specs.




I believe I would install a hyd pressure gage and monitor the pressure, and check and or reset the relief valves.

What I saw looked like rust, and that is caused by water getting to the steel. Dry cracked hose will allow water to permeate the cracked rubber. Hyd fluid leaking from the inside will not cause the rust.

Ozone will cause deterioration of rubber.

Some hoses are just better than others.

3000 psi pressure washers can inject water into the smallest of holes, in case someone cleaned the unit with water and other chemicals.

On the QD's, I would recommend to use both male and female from the same manufacturer, as some us ball tip and others use poppet tips, and some have different tip design. Same tips will ensure the flow is equal, and not restrictive.

 

[Discount Hydraulic Hose]

Even if they've only seen a few hours actual use, you said these hoses were purchased in 2005. That's at least 6 years of aging, and the actually hose material may be even older (check the manufacture date to be sure).

Since the steel wire reinforcement is embedded in the hose, it hasn't been plated or treated to resist corrosion. Once it gets exposed to moisture, corrosion is going to happen.

While it's impossible to say how water got into your hoses, it's obvious that it did. JJ's response was as good as I can give you.

One thing is certain. If any more of your hoses show signs of bubbling or cracking, replace them now, before you have another failure.

 

[J_J]

There is a way for you to test hoses, and that is with a manual 10,000 psi pressure pump. You would connect the hose to a high pressure manual pump with a gage, and pump it up until it burst.

I would have a wall between me and the hose, with the pump on the outside. It will not take much fluid after you fill the hose and let all the air out.

You would stroke the pump looking at the gage, and you will see max pressure before the hose or the fittings burst. Wear eye protection.

If you don't feel secure about doing this, then let a hyd shop can do the test for you if you can sacrifice one of your hoses.

 

[MHarryE]

Oil should never get to the braid unless the couplings used to make the hose assemblies were not the proper couplings for the particular hose. If it is hose from Anchor Coupling, the hose has a synthetic liner that is oil and water resistant. Two wire braids then give the liner the strength needed to hold its 3,000 psi working pressure. The rubber cover protects the braid from abrasion and weather. To be rusty water has to have made its way in through the cover someway. Are you sure it is Anchor hose? They only have hose plants in Missouri and Italy and in my experience have produced high quality product. If it is Anchor I would suggest sending a sample of your failed hose. You never know, they might give you a new set of hoses. It is hard to believe your system can build enough pressure to cause any kind of problem with this hose. My opinion is either hose manufacturing defect or improper hose couplings.

 

[hayden]

Sure sounds like defective hose, or perhaps defective assembly when the ends were crimped on.

Who is the hose manufacturer? Someone suggested contacting the hose manufacturer, which sounds like a good idea.

With the unit stored inside, sun exposure and resulting cracking can be ruled out.

 

[riprap]

Sure sounds like defective hose, or perhaps defective assembly when the ends were crimped on.

Who is the hose manufacturer? Someone suggested contacting the hose manufacturer, which sounds like a good idea.

With the unit stored inside, sun exposure and resulting cracking can be ruled out.

Yes, it is Anchor Coupling hose (OEM Kubota) R17. The rust bubbled areas and blow outs are well away from the crimped on connectors - at least 3 inches and some a foot. On some of the hoses, I can see/feel these lumpy areas over a considerable portion of the hose. I'll Take another look and note the date on the hose and also see if here is any difference between hoses.

I have replaced 6 of the hoses so far (2 RH stabilizer and all 4 on the swing), I also see a suspicious area on the other stabilizer that I will also replace, but so far no problems on the bucket dipper or boom (but a limited ability to inspect those very well. I used the hoe to dig some stumps out this week and made it through without any new blow-outs.

I will send Anchor a message and ask them if they would like to see some of this hose - I see they are right here in Michigan.