Quick coupler (skid steer style) will not disconnect with ANY pressure in the line?

[StAngerSandman]

I have a 3rd function diverter on my Mahindra 2555. I hav ea couple other attachments that I can hook up and disconnect with no issues. My new(ish) MTL grapple I can NOT get to disconnect without unscrewing the quick coupler and removing ALL pressure on the line? I don't mean "wiggle the joystick and remove the pressure", I mean "let the fluid out" to remove the pressure...

Do I just need to replace the couplings? Any other thoughts before I try that? I keep thinking there is something else going on, but not sure what it might be?

I appreciate any help / thoughts.

James

 

[Mikefromcny]

Are you pushing the couplers together, then sliding the collar back?

 

[Redlands Okie]

Some fittings are made to real ease under pressure. I wonder if you have a fitting on the new grapple that will not. Might try swapping fitting with one of the other attachments and see if it works ok. Then you would know weather to buy new fittings.

 

[finn1]

Any residual pressure behind the coupling will prevent it from loosening. Instead of “wiggling” the joystick, try moving it more deliberately.

I am not aware of any particular brand or design of coupling that would have a design feature that would allow removal if there is residual pressure in the line. That sounds like an accident waiting to happen, and a potential high pressure leak while in use....

 

[ericm979]

Wiggling the joystick won't do anything for the 3rd function circuit. Close the grapple and then turn the engine off. Turn the key back on so the 3rd function has power and then 'close' it some more. Give it at least a couple seconds. That should let the residual pressure drain out from the grapple and into the rest of the hydraulic system.

 

[Jchonline]

Wiggling the joystick won't do anything for the 3rd function circuit. Close the grapple and then turn the engine off. Turn the key back on so the 3rd function has power and then 'close' it some more. Give it at least a couple seconds. That should let the residual pressure drain out from the grapple and into the rest of the hydraulic system.

This. I had the same issue as op.

 

[Roger66]

I have a 3rd function diverter on my Mahindra 2555. I hav ea couple other attachments that I can hook up and disconnect with no issues. My new(ish) MTL grapple I can NOT get to disconnect without unscrewing the quick coupler and removing ALL pressure on the line? I don't mean "wiggle the joystick and remove the pressure", I mean "let the fluid out" to remove the pressure...

Do I just need to replace the couplings? Any other thoughts before I try that? I keep thinking there is something else going on, but not sure what it might be?

I appreciate any help / thoughts.

James

I have the same problem. any amount of exercise on the stick no luck. To me the problem appears to be since these couplers are designed not to leak compressing them to hook them up is causing a ever so small amount of fluid to move since I'm up against a closed valve I can't push hard enough to move that tiny bit of fluid by human power.

My solution, a bungee cord to hold the stick down allowing free fluid movement. In my case totally solves the problem, but it's more of a workaround than a fix. The older pioneer connectors would simply leak out this little bit of fluid. If there is a better fix i'd love to hear it.

 

[laurencen]

for what its worth on my Bobcat any attachment where cylinders are involved you need to lower them down, I had a grapple that was a pain to remove the couplers, the cylinder would compress over time and build pressure to the point I could not get it uncoupled, by holding the valve open for a few seconds each way fixed it most of the time

 

[metalbender]

Yup, turn the tractor off, turn ign on, exercise the lever with diverter powered up and disconnect. Generally if I'm going to take off an attachment, I disconnect before starting the tractor. Sometimes the implement hoses will build pressure in the sun making it impossible to hook up. Have to smack the coupler center hard to let the pressure off. Frustrating when one is a newbie to the system.

 

[mred2]

metelbender is right. I had the same problem. When I take off my grapple, I set it down, shut the engine down, release pressure on all pressures, turn key back on without starting and hit the diverter switch, both ways. I than have no problems disconnecting the hoses. After the grapple sets for a few weeks, pressure will build up. I make sure that there is no pressure in the tractor side and than I have to tap the center of the connectors on the grapple side to release the pressure. One reason, I don't like flat face couplers.