Cylinder weak and slow

[chartersj]

The hydraulic cylinder for the arm on my backhoe is weak and slow when extending it and normal when retracting it. The rest of the cylinders work as they should,,, can anyone point me in the right direction in where to look to correct the problem?

 

[BeezFun]

Check the quick disconnects first, that's cheap and easy. If that doesn't help, try switching the hoses for retract and extend and see if the problem follows the hose or the cylinder.

 

[deereman75]

What make and model of backhoe is this? Different companies have different cylinders.

 

[chartersj]

Check the quick disconnects first, that's cheap and easy. If that doesn't help, try switching the hoses for retract and extend and see if the problem follows the hose or the cylinder.

Ok good idea

 

[chartersj]

What make and model of backhoe is this? Different companies have different cylinders.

It’s a MF50A with factory massey backhoe

 

[BeezFun]

I was thinking about your symptom, it could be that there is rust or crud in the bottom cup of the valve body so the spool can't move all the way in one direction but moves freely in the other. You might be able to tell by comparing the valve lever movement in one direction with the other.

 

[chartersj]

I was thinking about your symptom, it could be that there is rust or crud in the bottom cup of the valve body so the spool can't move all the way in one direction but moves freely in the other. You might be able to tell by comparing the valve lever movement in one direction with the other.

I can confirm the problem follows the hoses. So that would rule out the cylinder. The spool has the same travel as the others. This is the older style with a row of handles so it’s easy to tell. It is more useful this way other then the fact now you have to move it in the opposite direction which is in turn makes it opposite to the bucket curl and makes it even more awkward to use. I did notice on that handle when I pull it all the way toward me it will stick,,, none of the other handles will do that. Not looking for a new machine,, it is a ‘75 but was wondering if that may be a symptom of something internally wrong with that valve

 

[BeezFun]

Ok I'd suspect the valve. I'd drop the bottom cup, it's usually held on with 4 cap screws, you can probably get at it without dismounting the valve. If that's a detente valve all kinds of little bearings and springs may fall out, be ready. If it's full of crap that's probably the problem, but even if it isn't try using the valve with that cup off. If it still doesn't work you may need to take it to hydraulic shop depending on your ambition.

 

[chartersj]

Ok I'd suspect the valve. I'd drop the bottom cup, it's usually held on with 4 cap screws, you can probably get at it without dismounting the valve. If that's a detente valve all kinds of little bearings and springs may fall out, be ready. If it's full of crap that's probably the problem, but even if it isn't try using the valve with that cup off. If it still doesn't work you may need to take it to hydraulic shop depending on your ambition.

Ok perfect I will try that first and see how it goes. Thanks for the help!

 

[BeezFun]

The other thing, since it's so old, if you remove the valve lever and take the top boot off, inspect the condition of the spool where it enters the valve body. If it's built up rust over the years that might be preventing the spool from moving all the way into the body.