Backhoe boom drop

[balsam]

I am having a problem with my Woodmaxx backhoe attachment. Last year when I took it off to put away, it was fine. I store it outside under a tarp. It does get well below freezing where I live here.
I hooked it up recently and thought everything was working fine until I noticed what I think is called the boom dropping, by itself, relatively quickly.….from full up to down in about 15 minutes, which it never did before.
There doesn’t seem to be an external leak anyplace I can see, so I assume there is an internal leak around the cylinders piston seals or through the valve that operates it. Is it possible that the valve is not totally centering itself?
I guess my question is: how do I determine where the problem is, if in fact it is one of those two possibilities or something else.
I wonder if anyone has had a similar problem or has any ideas for me.

 

[nyone]

You can crack the return hose with the tractor off and it in the air. In theory it will have a small amount of fluid but the valve should be holding most of the pressure.

You could also crack the suspect cylinders down hose as this shouldn't have pressure if the up side of the cylinder is holding.

 

[balsam]

Thanks ngone: If I understand your explanation. I lift the boom on the backhoe to the highest position, then take the hose off the piston end of the cylinder to see if it still drops and how quickly the oil comes out.
if it still quickly drops I can assume the piston seals are the problem.
Is that the idea?

 

[nyone]

Depends on what way the cylinder is on the machine but yes.

 

[balsam]

I’ll try that, but it may be hard to do and even repair because the cylinder is actually inside the boom itself. I have to figure out how it comes out
I am going to call Woodmaxx tomorrow and see if they have any advice. I also want to find out if they have seal kits for those cylinders.

 

[LD1]

Does the boom Have a transport lock or pin? Use that when not using the backhoe. When using the backhoe the rate of bleed down shouldn't effect operation

 

[rScotty]

Be careful and think it through. For example, I don't think that my backhoes have a dedicated "return line" to the cylinders. The hydraulic lines alternate as pressure and return depending on the valve position. With the motor off, which is the return depends entirely on the position of the boom.

Basically I think that what you want to do is isolate your control valve from the cylinder so that you can determine which one needs attention. And you probably want to do it in such a way that you can continue using the hoe while you work on the problem. You can do that by simply screwing in a set of high pressure ball valves in line with the hydraulic hoses between the valve and the boom. That way you can extend the boom, shut the motor off, close off the ball valves, and see if it still drops. If so, the problem is in the cylinder.

Two ball valves and the necessary thread adapters will set you back between $40 and $70 at SurplusCenter.com.