Attaching quick couplers?

[Tarnold]

First time after initial install hooking up grappler. The only way I could get the couplers to latch was loosen the hose at the cylinder to relive the pressure and losing a cup of hdy fluid. When I unhooked the two lids were closed down. So how do I leave the lids so that it will be easier the next time? The couplers are not flat faced, but have the small cone(forget the proper name right now).

 

[rd_macgregor]

I'm eagerly awaiting answers, too. My grapple rake has flat-face couplers, but one of them will only attach when it is really cold out. Last weekend I failed to get that one connected, so had to give up on using the grapple. Midweek it was cold (just about freezing) and I coupled the two on the grapple together with no problem...but as soon as it warms up, I expect problems again. Is it the way I left it when I parked/dismounted it?
I don't like loosening the hose to relieve pressure; I worry that I'll not get it totally sealed again.
Bob

 

[ovrszd]

This is a learning curve in hydraulics.

There is no air in the system to cushion expansion/contraction. So, if you unhook the couplers with the fluid cold or even after use on a cold day, then try to rehook when it's warm, you've got problems.

The best I can, I plan my unhooks when the fluid is warmed from use or in the heat of the day. Or if I drop my Grapple to do a simple task, I rehook as soon as I'm done before the fluid has time to expand in the heat of the day.

Easist way to relieve pressue is to push the male connector against something to depress the ball or pin and relieve the pressure. Make sure you throw a rag over it or you will get a bath in oil.

I've threatened to T a ball valve into one line to open and relieve pressure but haven't yet.

The secret is heat/cold. Nothing wrong with your equipment or your methods. This problem can arise in a couple hours if unhooked in hot sunshine!!!

 

[ovrszd]

Oh forgot to mention, I use flat faced couplers too. Harder to depress them and relieve pressure.

 

[newbury]

I've successfully used a cold water bath over the hoses.

 

[EddieWalker]

After a couple of years of fighting my couplers, I gave up and took them off. It's just easier to screw plugs into the lines when I'm not using it and then screw the hoses together when I need it.

Eddie

 

[ovrszd]

I've successfully used a cold water bath over the hoses.

That would work, never thought of doing that. Probably wouldn't take any longer than unscrewing a coupler if parked where it didn't make a mess.

 

[ovrszd]

After a couple of years of fighting my couplers, I gave up and took them off. It's just easier to screw plugs into the lines when I'm not using it and then screw the hoses together when I need it.

Eddie

Eddie, that sounds messy but it would work.

 

[Tarnold]

Talk some more about that ball valve relief. I pushed that male coupler with all I had but it would'nt crack at all. I'm pretty sure I had been running the tractor (HST) for a good bit so the fluid should have been pretty warm.

 

[Lunk]

Those flat-faced couplers can be a b****. I remember the first time I tried re-hooking up my first grapple, it must have taken me a half hour...

I don't know if it hurts anything (Someone please advise if it does!), but on my Branson I kept an extra bungee cord that I hooked up to the lever for my remotes. Before trying to couple the hydraulics, I would use the bungee to activate the control lever one way or another. If the first coupler went together easily, I would try the other, and if it was no go, switch the bungee to activate the other circuit.

Generally the stubborn one would click right into place without issue. Maybe all it was was the temperature of the oil as previously mentioned, but it sure seemed to work for me.

Hopefully it was not damaging anything!

Lunk

 

[ovrszd]

Pushing in the ball might be difficult, depending on how much pressure is there. You still should be able to grab the hose with a firm grip and slam the ball into a flat metal surface and get it to spew fluid. Again, be prepared for a bath if it's got a lot of pressure.

This brings up another point. Never uncouple with pressure in the system. Always make sure the cylinder(s) isn't at maximum length or retracted all the way. You don't want to uncouple with pressure already in the system. Then when heat builds up you have a serious problem. That might be where Tarnold is with his now.

When I'm uncoupling I shut the tractor off. Then I move the control lever all directions to release any pressure in the system. Then I uncouple the hose. In reverse, I do the same thing when coupling onto something that gives me problems. Shut the tractor off, release all pressure in it's couplers, then couple hoses.

I use my hydraulics a LOT on various equipment. I have 3rd function on my FEL as well as triple hydraulics on the rear of the tractor. I remove my FEL 6-10 times a year. I'm practiced at proper hooking/unhooking. I rarely have a problem now since I'm conscious about how and when I do it.

 

[ovrszd]

Those flat-faced couplers can be a b****. I remember the first time I tried re-hooking up my first grapple, it must have taken me a half hour...

I don't know if it hurts anything (Someone please advise if it does!), but on my Branson I kept an extra bungee cord that I hooked up to the lever for my remotes. Before trying to couple the hydraulics, I would use the bungee to activate the control lever one way or another. If the first coupler went together easily, I would try the other, and if it was no go, switch the bungee to activate the other circuit.

Generally the stubborn one would click right into place without issue. Maybe all it was was the temperature of the oil as previously mentioned, but it sure seemed to work for me.

Hopefully it was not damaging anything!

Lunk

No, you aren't damaging anything. If your valve is a "float" valve you can do the same thing by detenting the lever into float. This works to relieve pressure in the tractor's system. But it does nothing to relieve pressure built up in the attachment's hydraulics.

 

[k0ua]

Here is what I do, and I have the AG couplers.

When removing, stop engine, and work the control valve back and forth, the lid of the grapple is resting on the teeth, so it is relaxed.
Pull apart the connectors from the tractor. Then I push the male and female on the grapple together immediately and then open them again so some fluid pukes out. If not enough fluid comes out do it again. The goal is to reduce the volume of fluid in the lines of the grapple. I leave the couplers mated together to keep out dirt and equalize pressure in both sides. When ready to re-install open them up and some fluid should puke out of the couplers, then hook them up to the tractor, you should have no problems. Of course it goes without saying that the engine/pump is off on the tractor. I have been doing this procedure for 9 months on this grapple, and I haven't had any problems so far.

 

[Browneyesvictim]

Overszd is spot on. This is called thermal expansion. In my 30+ years background in hydraulics, I have come to have a love/hate relationship with quick couplers. They have their tradeoffs. The symptom you describe is a common one. Even with the “connect under pressure” rated couplers that are “supposed” to prevent this, they all seem to suffer this same issue. Fluid pressure is created by thermal expansion and becomes trapped behind the plunger seat. Depressing the plunger is the simplest most direct way to get them re-connected. It may take a dowel of some sort and a small hammer to tap inside the female half if that’s the side that’s got pressure. You can try a couple other different methods. Overszd stated a couple of those: Relieve as much pressure as you can before disconnecting by moving the controls in all directions with the tractor turned off. Make sure there is nothing suspended hydraulically or that can settle with gravity to apply pressure in the hydraulics. Install a T in the line with a JIC cap or small ball valve that can be bled. After the implement is disconnected from the tractor, connect the 2 corresponding hoses (A & B ports of cylinder) together. Get rid of the quick couplers altogether (Judicious use caps and plugs or connect together to prevent contamination is essential!) Try a different type/style of quick coupler-I have come to prefer the threaded type of quick coupler that you can get the mechanical advantage with to overcome the pressure with.

 

[newbury]

Actually the PREFERRED method is to buy one tractor per implement

One can dream

 

[pmsmechanic]

Newbury you make me laugh. I rarely have trouble hooking up hydraulic couplers. Basically only if I unhook cold and try to reattach after the weather has warmed up. The odd time I have to wrap a rag around the tip and I usually just give it a tap with a hammer.

 

[Tarnold]

Op here. As this seems to be a common problem, think I will get my machinist son to make me a C clamp thingee that I could use to depress that tit and release the pressure. just don't like the idea of hitting with a hammer

 

[Kioti Tom]

First time after initial install hooking up grappler. The only way I could get the couplers to latch was loosen the hose at the cylinder to relive the pressure and losing a cup of hdy fluid. When I unhooked the two lids were closed down. So how do I leave the lids so that it will be easier the next time? The couplers are not flat faced, but have the small cone(forget the proper name right now).

The name of the coupler you have is the poppet valve. this is the one with the cone. The other style
of AG coupler has spring loaded balls in it. these leak more. The third style is the flat face like is used
on the skid steers.

Lots of good info on this thread so you should be ok

Tom

 

[ovrszd]

After uncoupling an attachment I always hook the two hoses together to reduce contamination. I've never tried James' idea of coupling/uncoupling repeatedly to let out pressure. I use flat faced couplers so not sure that will help.

Newbury's idea is appealing. Just can't imagine how I'll get it past the "Financial Manager".

Tarnold, I've never hit one with a hammer as I can clearly see the squirting Hyd Fluid coming at me. Before I'd build a device to clear the pressure, I'd T in a Ball Valve to let it out if needed.

Kioti Tom is right on with his descriptions of the various types. I use Flat Face because I trade off use of my attachments with a Bobcat, they use Flat Face.

 

[k0ua]

Richard, do the Flat Face 16028 couplers "puke" out any fluid at all or is it just less than the AG's (ISO-5675) like I have? If they don't leak at all or not much, then my technique would not help. But it sure works for the AG connectors. Each time you couple and uncouple and AG connector it loses just a little fluid. Not all that much, but some.