New Excavator Quick Connect Won't Close

[requiredwhen]

I have an XCMG XE75 excavator that I’m trying to install a quick coupler to. The machine was plumed for a coupler at the factory with the valve and safety switch. I only had to attach the quick coupler and connect the hoses from the cylinder to the machine.

My problem is that pressure is always going to the quick coupler cylinder no matter if the safety switch is on or off. And it only provides pressure from one hose. So, if the hoses are connected one way the cylinder only extends (and I can’t hook onto a bucket) and if I switch the hoses the cylinder will only retract (and I can’t lock the bucket in).

He’s a video showing how it is pressurized when the safety switch is on or off:

Maybe it was plumbed wrong from the factory? I’m not sure where to start with this.

Thanks

 

[Rustyiron]

Sure looks like it. Is that line for your thumb?
I'm thinking that if it is, mechanically relieve the pressure (loosen up the fitting) and attach it and see if the thumb operates.
Maybe I'm not understanding?

 

[requiredwhen]

Sure looks like it. Is that line for your thumb?
I'm thinking that if it is, mechanically relieve the pressure (loosen up the fitting) and attach it and see if the thumb operates.
Maybe I'm not understanding?

The thumb is working good. I installed it at the same time as the quick connect.

The two long hoses on each side are for the quick connect. I'll pin them up once I get the problem sorted.

Thanks

 

[Fixastuff]

Are you supposed to hit the switches then curl or retract the bucket to move the coupler cylinder? That's how some work.

 

[requiredwhen]

Are you supposed to hit the switches then curl or retract the bucket to move the coupler cylinder? That's how some work.

That's how I've done it in the past on other machines.

In the video I try to retract the bucket with the switch off, then on. Neither work. I'm wondering if maybe there is some extra step I'm missing. I'll call a dealer and see if they can give any advice. It's a holiday here so will have to wait till Monday.

 

[WranglerX]

Seems to me you have a malfunction in the switch/solenoid valve wiring .. Unit plumbing may be correct but is not responding to electrical control properly.... Would seem to me that you need to validate power to solenoid valves is correct for what operating position switch is in...

 

[requiredwhen]

Seems to me you have a malfunction in the switch/solenoid valve wiring .. Unit plumbing may be correct but is not responding to electrical control properly.... Would seem to me that you need to validate power to solenoid valves is correct for what operating position switch is in...

Thanks, I checked the switch and the connection at the solenoid both are working as they should. I checked the resistance on the solenoid and it's also good. Next stop is the valve.

I haven't checked a hydraulic valve before. I looked at some you tube videos and it seems straight forward. We'll see.

 

[Fixastuff]

Could it have a second safety button/switch? I don't have the hydraulic coupler for my machine but the ones that do have a button you have to step on, then flip the switch before the coupler will activate.

 

[requiredwhen]

Could it have a second safety button/switch? I don't have the hydraulic coupler for my machine but the ones that do have a button you have to step on, then flip the switch before the coupler will activate.

The weird thing is that the flow to the coupler is active if the switch is on or off. It seems like the valve isn't closing. When I switch the hoses and turn the machine back on the coupler cylinder automatically opens or closes. Planning to take a look at the valve tonight or tomorrow.

 

[Michael In Tennessee]

I'm thinking this might be a safety thing. You always have pressure to the rod end of the cylinder. This being the normally closed position for the system. Then, you activate the open function. Piston diameter being larger on the back side of the piston forces cylinder open so the bucket can be removed.

Its a wild guess but some systems work this way.