Hydraulic Cylinder Problem

[RamTruckMan]

I bought a used three point backhoe. The backhoe is about 10 years old but was barely used. The seller said it was only used about 20 hours and hadn't been used the last six years. The paint is still inside parts of the bucket.

Anyway, the boom cylinder call be pulled in and out manually, however, it will not move in or out with the levers. I have loosened the hose connectors at the cylinder and both connectors will squirt fluid when the levers a pushed in or out. The cylinder does not leak. All other cylinders work ok.

What might be some of the causes of this problem?

 

[teg]

Can you swap the hoses from another valve to power that cylinder just to test it out under power?

 

[kennyd]

The piston seals may be bypassing...try this: Take on hose off, now operate the lever to energize the hose that you left on, it fluid shoots out of the other end of the cylinder then the seals are bad. It could also be that the valve has a PRV (pressure relief valve) for that function and it's stuck.

 

[RamTruckMan]

Thanks for the reply.

Yeah, I did that. Same thing, it will squirt fluid at the connection, if I loosen them a little bit, but the cylinder doesn't do anything, just limp. This cylinder is on the boom section, that the bucket is attached to and that section will swing back and forth, if I push it by hand.

 

[kennyd]

Thanks for the reply.

Yeah, I did that. Same thing, it will squirt fluid at the connection, if I loosen them a little bit, but the cylinder doesn't do anything, just limp. This cylinder is on the boom section, that the bucket is attached to and that section will swing back and forth, if I push it by hand.

Well then, bad seals OR the Jesus nut that holds the piston onto the rod came off. Either way the cylinder needs to be removed and taken apart.

 

[RamTruckMan]

I see you are from Maryland to. I am in Cumberland. I will try that, to check the seals. Where would I look for the pressure relief value? The other thing that might be helpful is, that the hydraulic port at the far end of cylinder has a metal extension tube that runs along the cylinder down to the base of cylinder to connect the hydraulic hose. This tube will get warm when pressure is applied.

 

[RamTruckMan]

Thanks, I will do that. I will try and rigg up some kind of a gland wrench. On the other hand It will probably be the simplest to just take someplace and have them look at it.

 

[kennyd]

Post some pictures of the cylinder and valve if you can.

 

[RamTruckMan]

I took the cylinder off and there was no fluid in the cyclinder to drain out. Does that mean the cylinder could be air locked or some other problem. Fluid will squirt from the detached hoses when actuated. I have attached photo if that is helpful.

 

[J_J]

RamTruckMan,

In your first post. you said the cyl did not leak. and that fluid would flow out the hose. Did you check the pressure on the system while operating the valve?

Put a gage on the work port and activate the valve momentary to see if the valve will go into relief and check the pressure. .

With the base end plugged, could you pull the rod out of the cyl?

 

[kennyd]

I took the cylinder off and there was no fluid in the cyclinder to drain out. Does that mean the cylinder could be air locked or some other problem. Fluid will squirt from the detached hoses when actuated. I have attached photo if that is helpful.

Have you tried to pull the rod out? If so-how much resistance is there? I am still thinking the nut came off inside.

 

[RamTruckMan]

The rod floats free, I could pull backhoe boom out and the rod would push in. Let the boom drop and rod would pull out. The rod floats free, with the cylinder off the tractor.

I think, I have a high pressure hydrualic gauge. I will see if I can find it and get some fittings to attach it to the value.

 

[RamTruckMan]

It pulls a little hard, but with a little leverage it moves full stroke in and out. I will try opening it up this weekend and see what it looks like. Who knows, I may be able to get it back together.

 

[kennyd]

It pulls a little hard, but with a little leverage it moves full stroke in and out. I will try opening it up this weekend and see what it looks like. Who knows, I may be able to get it back together.

\

That will be the only way to know at this point...Take some pictures for us:thumbsup:

 

[RamTruckMan]

One other thing, when the rod in all the way in, about an inch or two of the rod sticks out of the cylinder. Is that normal, or could that indicate the rod is hitting the nut keeping if from pushing all the way in.

 

[kennyd]

One other thing, when the rod in all the way in, about an inch or two of the rod sticks out of the cylinder. Is that normal, or could that indicate the rod is hitting the nut keeping if from pushing all the way in.

Not normal...I bet you could pull that rod all the way out!

 

[aczlan]

One other thing, when the rod in all the way in, about an inch or two of the rod sticks out of the cylinder. Is that normal, or could that indicate the rod is hitting the nut keeping if from pushing all the way in.

I believe (from your picture) that it should go in to the paint line on that cylinder.

Aaron Z

 

[J_J]

I do believe the nut has come off the bottom of the rod that secures the piston. That is why you have no movement on the cyl rod, and the reason the rod moves freely.

Did you say it only had 20 hours on the BH?

 

[stewy]

Hi, first post here. Have done alot of reading on here and gained some valuble
info.just rebuilt the lift cyl. on my loader and all I can say is what a difference! Now back to this thread I guess it could be a piston nut but maybe just the piston o-ring blown to pieces as it was in my case. Thanks for all the good info.

 

[kennyd]

Hi, first post here. Have done alot of reading on here and gained some valuble
info.just rebuilt the lift cyl. on my loader and all I can say is what a difference! Now back to this thread I guess it could be a piston nut but maybe just the piston o-ring blown to pieces as it was in my case. Thanks for all the good info.

Welcome to TBN Stewy