Front hydraulic couplings for grapple not releasing pressure

[RinconVTR]

Strange thing. The grapple fully closed, power off, actuate the hydraulic lever to what I thought would relieve hydraulic pressure.

Remove the two quick connect hoses for the grapple, then try to reconnect...no-go. Pressure remains in (apparently) the grapple side.

Any ideas to easily address this?

 

[Sysop]

Wrap the side with the ball in a rag and press the ball against something to relieve the pressure.

Basically you've disconnected it at a lower temp than you're trying to connect it. Higher temps increase pressures. It's mostly inevitable. Best option is connect the two QDs together when you take your grapple off. If pressure has increased while it is setting, you'll relieve enough pressure disconnecting the two, that attaching them to the tractor will be easier.

If possible, attaching the two QDs on the loader together allows fluid to pass through, so if you accidently bump the switch you don't load one of the lines up with pressure.

 

[Oldtractorfixer]

I can't tell you how many times I've been sprayed with hydraulic fluid trying to do this. Hit the male end on the loader frame to relieve pressure and spray everywhere not just me but the loader etc. So what to do. I get/carry a cresent wrench, crack the hydraulic line at the cylinder, let it leak the pressure off in a dribble and put it together.

 

[k0ua]

Best option is connect the two QDs together when you take your grapple off. If pressure has increased while it is setting, you'll relieve enough pressure disconnecting the two, that attaching them to the tractor will be easier.

After I started doing this, I have never had a problem connecting up. ^

 

[Sysop]

I can't tell you how many times I've been sprayed with hydraulic fluid trying to do this. Hit the male end on the loader frame to relieve pressure and spray everywhere not just me but the loader etc. So what to do. I get/carry a cresent wrench, crack the hydraulic line at the cylinder, let it leak the pressure off in a dribble and put it together.

A rag is easier to carry around/keep handy, and captures any spray. No dribbles to hunt a rag to cleanup after also. It is simply much faster to wrap and tap than muck around with wrenching the end loose. The whole purpose of QDs is so wrenches aren't needed to plumb lines together.

 

[N2DFire]

Strange thing. The grapple fully closed, power off, actuate the hydraulic lever to what I thought would relieve hydraulic pressure.

Remove the two quick connect hoses for the grapple, then try to reconnect...no-go. Pressure remains in (apparently) the grapple side.

Any ideas to easily address this?

I think we're all making a couple assumptions
1) That you're issue is on the tractor side and not the grapple side.
2) That you're using a rear remote to operate the grapple.

If you are using a diverter or 3rd function valve then having the power off is most likely not letting them activate to relieve pressure in the grapple circuit.

 

[Sysop]

Can't speak for anyone else, but I never assumed either of those things.

 

[ovrszd]

His problem is on the attachment side.

Activating the circuit before disconnecting won't fix this problem.

Connecting the two hoses together helps slightly. But this is only possible if the QC's are setup one male one female at the attachment side.

I'm very conscious of the temps when I unhook, rehook. Direct sunshine will also cause this problem. Flatface couplers are worse because they are designed to not leak during connection.

 

[ovrszd]

Can't speak for anyone else, but I never assumed either of those things.

Me too.

Or is it me neither.

I always get those confused.

 

[k0ua]

One thing I also do is immediately after taking the grapple off (while the fluid is hot) is to couple the male and female QD's together and then uncouple them. This will let a little fluid leak out. Then I couple them again. Now there is a "deficit" of fluid in the lines. Even if it cools down and then heats up due to a rise in temp, there will be a little space for expansion. And it is not likely that it will get hotter than the fluid was while the tractor and grapple was in use. In any case, I NEVER, EVER have a problem with connecting the lines back because of a pressure rise in the lines.