Root Grapple Coupler Frustration!

[KubotaToy]

Is the pressure on the attchment, on the tractor, or both?

Just the grapple has pressure, I can relieve the pressure on the tractor by cycling the third function valve on the tractor. BTW- I had the same issue with my skid steer when hooking up the grapple.

 

[swick1]

I think hooking them together will just equalize the pressure not relieve the pressure.

You are right it will equalize the pressure.

The piston side has more area than the rod side. The rod side has less area and therefore less force. The extra force generated on the piston side as the pressure rises has to go somewhere and it increases the pressure on the rod side to reach equilibrium of forces so that the cylinder doesn't move.

Imagine the piston as having springs on either side of it. When you leave it disconnected and it heats up the springs are compressed unevenly. This makes it really hard to reconnect. When you connect the hoses together it becomes easier to reconnect because both springs are equally compressed.

 

[lhansman]

I follow the procedure outlined by Roger (L45 off, key on, front remote switch on and then press the open and close buttons four or five times each) and that works fine on my L45. I switch between my 4-in-1, hydraulic forks, grapple and in the winter my extendable snow blade and it works fine for me.

I connected the hoses on one of my attachments together once and had a heck of a time getting them apart again so I would not recommend doing that.

Regards,

Lauren

 

[94BULLITT]

You are right it will equalize the pressure.

The piston side has more area than the rod side. The rod side has less area and therefore less force. The extra force generated on the piston side as the pressure rises has to go somewhere and it increases the pressure on the rod side to reach equilibrium of forces so that the cylinder doesn't move.

Imagine the piston as having springs on either side of it. When you leave it disconnected and it heats up the springs are compressed unevenly. This makes it really hard to reconnect. When you connect the hoses together it becomes easier to reconnect because both springs are equally compressed.

Dave said he can take his grapple hoses right off and try to put them right back on and he has a hard time with them. So I can not see heat being a factor there.

I follow the procedure outlined by Roger (L45 off, key on, front remote switch on and then press the open and close buttons four or five times each) and that works fine on my L45. I switch between my 4-in-1, hydraulic forks, grapple and in the winter my extendable snow blade and it works fine for me.

I connected the hoses on one of my attachments together once and had a heck of a time getting them apart again so I would not recommend doing that.

Regards,

Lauren

Thanks for the advice.

When I went to the dealer to get my tractor they had a blade on it to show the 3rd function worked. The guy unhooked it from the tractor and connected the hoses. I bought it about a month and had no problem getting them apart or on the tractor. It has been setting since the first of september with the hoses hooked together. I will try them to see how easily they unhook. Maybe I have been lucky so far.

 

[J_J]

I have posted about this many times.

Some QD's can connect under low pressure, and others at full operating pressure. Regular or flat faced QD's.

If you can't push the male end on a flat piece of steel to release pressure, then keep reading.

An overall cure I have posted many times is to install a tee before the QD, and add a needle valve.

Just open the needle valve and a little fluid may come out, but the pressure is released. Just common logic says it will work.

It will work with a cyl or motor circuit.

Make sure you close the valve before starting the machine.

Should work every time.

 

[94BULLITT]

I was able to get the hoses apart on my blade easily.

Some QD's can connect under low pressure, and others at full operating pressure. Regular or flat faced QD's.

So any flat faced or regular QD may or may not connect with pressure?

 

[59 Sons]

Ive ocasionally had the same problem with my grapple on my M59. I try to make sure my grapple is totaly closed when I take it off, and dont touch my third function before I hook up. But I still end up losening the grapple hose when it just cant be forced. I like the idea of adding a bleeder valve though. No solution here, just sympathy.

 

[Timm250]

I had the same problem with my grapple. Now I close the grapple about 1/2 way & shut off the engine, turn the key on, work the levers & let the grapple drift closed from it's own weight. Since I have been doing this I haven't had any problems connecting the hoses the next time I use it.

 

[J_J]

I was able to get the hoses apart on my blade easily.



So any flat faced or regular QD may or may not connect with pressure?

Parker - CONNECT UNDER PRESSURE QUICK COUPLINGS

http://www.parker.com/portal/site/P...IES+QUICK+COUPLINGS+-+NA&Wtky=QUICK+COUPLINGS

 

[94BULLITT]

Parker - CONNECT UNDER PRESSURE QUICK COUPLINGS

http://www.parker.com/portal/site/P...IES+QUICK+COUPLINGS+-+NA&Wtky=QUICK+COUPLINGS

Thanks. I saw some at tsc that were labeled "connect under residule pressure." I'll have to get the part number off of mine to see what they are.

 

[don white]

I have the same problem and yes bleeding the pressure works but is a pain. I have found that if you keep pressure on the fittings they will slowly go together. Just keep pushing and in a minute or so they connect. I have the Kubota third function with the buttons and you do have to bleed the pressure but the fittings are still difficult to connect.

 

[94BULLITT]

Is this problem primarily a kubota problem?

 

[swick1]

Is this problem primarily a kubota problem?

I think it is user error. My qd's are hard to use sometimes. I have safeway and john deere qd's. I have to relieve them with a rag and punch sometimes.