How to releave pressure to make connection?

[AKfish]

If you have the skid steer type of hydraulic quick disconnects, with the flat face, they are the biggest PITA I have seen in the hydraulic world.

Whoee...! They are alot of great fun!!

With all the cold we've had this winter the latest problem has been with the female collars sticking. And the inside ring will remain stuck in a recessed position. Add in a tiny bit of snow here and there for some ice... Aarrgghh!

I'm gonna give the extra connectors a try this next summer. With the flat-face connectors - there's no simple way to bleed off the excess pressure after the sun gets a shot at the black hoses and cylinders. And packin' around 7/8" and 1 1/4" and 3/4" open ended wrenches is one more straw for the PITA pile!

J_J's note about a cap fitting on the end of the extra connectors is a good idea as well. Would make bleeding off the fluid a simpler exercise.

AKfish

 

[Samandothers]

Dave I like the caulking gun idea for some 'extra' strength to push the connectors together.
I am having a bit of trouble trying to visual the extra connector for bleeding some fluid. Are yall suggesting removing the existing quick fitting and add a 'T' and replace the fitting on one side of the 'T' and a cap on the other?

 

[J_J]

Dave I like the caulking gun idea for some 'extra' strength to push the connectors together.
I am having a bit of trouble trying to visual the extra connector for bleeding some fluid. Are yall suggesting removing the existing quick fitting and add a 'T' and replace the fitting on one side of the 'T' and a cap on the other?

No, The additional QD is only put on one end , say the QD female. You take a male QD with a pipe cap on it and plug it into the female QD, this lets the excess fluid caused by heat to expand into the cavity of the QD, and pipe cap.

It is a two piece adapter , one male QD, and one pipe cap. You could also bolt another fitting on the tractor to store this adapter, when it is not being used on the attachment.

 

[CurlyDave]

I am having a bit of trouble trying to visual the extra connector for bleeding some fluid. Are yall suggesting removing the existing quick fitting and add a 'T' and replace the fitting on one side of the 'T' and a cap on the other?

No, I do it like J_J says.

Go down to the hydraulic store and buy an extra connector, no hose, no "T", just a plastic pipe plug or pipe cap depending on what your connector has on the back of it. The secret is to put the extra connector on just as soon as you remove the implement from the tractor, before it has any time to sit & warm up.

I just screw the pipe plug or cap on by hand, which is enough to keep dust out, but doesn't really seal pressure. This eliminates making and breaking pipe connections on the back of the connectors, which I view as a much greater source of contamination in the hydraulics than any dirt getting through a hand-tight plastic pipe thread.

In many cases, you will only need one of these as J_J suggests. OTOH when I store my grapple, I close it before disconnecting. If I happen to put the dummy connector on the wrong hose connection, the closed grapple will allow pressure to build up in one side of the cylinder.

This prompts me to spend some time "blessing" the hydraulics, in a way that would make my pastor blush. It is just easier to buy two connectors and put one connector on each hose from the grapple. Same with my 4-n-1 bucket.

I actually have two sets of extra connectors one for each hydraulic attachment. There are times when they sit side-by-side in the yard while I use the forks.

 

[banjodunn]

if the thought of all these ideas does not interest there are quick couplers available that allow you to connect under pressure your local hyd shop should be able to help you out with these or you could try bare co they have a good site very helpful and good hyd page for those that dont know alot about hyd fittings i.e fitting sizes and styles etc

 

[J_J]

It seems like there is no standard for using QD male and female fittings on hydraulics. It would just make common sense to do this, for this reason. A hydraulic motor would always run in the right direction, by pushing on the lever, and reverse by pulling back. On cylinder action, the cylinder should extend to push down, and close by pulling back. The grapple would extend and close by pushing fwd. etc.

If I remember correctly, when you have the male and female QD's, the male goes on the output line/pressure line, and the female goes on the return line. Maybe someone can confirm this.


On the subject of connecting, flat face couplers with 3000 psi, with an attachment that has been in the sun for 8 hours, I have never tried that, but I have read that it can be done at low pressure, whatever that is. Maybe someone can confirm that fact.

 

[Samandothers]

Thanks for the clarification on the pipe cap to relieve the pressure. I understand now what is being suggested. I feel a bit better knowing this is somewhat of a common issue there are ways to remedy or reduce the problem.
thanks again all!

 

[jmc]

I stumbled across a simple solution to this that I don't think has been mentioned yet.

I have a WR Long grapple with their solenoid controlled valve on my Kubota. Since the grapple is used on a tracked loader as well, I plumbed the Kubota with the flat faced couplers, which magnify this problem. Do the usual pressure relieving procedures. Then with the motor off, try holding the valve open while making the connection. (Of course the valve must have power to it even though the motor is off.) Granted, it takes a second person on the operator's platform or a c-clamp or some duct tape to hold the button down during the hookup but previously it would only insert about 1/3 of the way and while holding the valve open, it goes in like butter.

My theory is that even though you go thru the various ways of relieving pressure, there is still a fixed, noncompressible volume of fluid trapped in a short hose between the valve and connector. Components within the quick connectors must displace a small amount of fluid to connect and there is no place for that fluid to easily go unless the valve is open at the time.

I have the same problem on the tracked loader and intend to try this the next time I hook up a hydraulic attachment on it. In the meantime, if anyone tries it on a skid steer type machine, let me know if it works. I'd also be curious if manual valves have this problem and if bungy cording them open helps with it.

One of these days I will hook up a momentary switch next to the QA connectors on the front of the Kubota. This switch will open the solonoid valve from the front to eliminate the second person or improvisation.

John

 

[Cat_Driver]

I have the same problem on the tracked loader and intend to try this the next time I hook up a hydraulic attachment on it. In the meantime, if anyone tries it on a skid steer type machine, let me know if it works. I'd also be curious if manual valves have this problem and if bungy cording them open helps with it.

In the CAT they have a button in the cab that you push and it releases the pressure in the lines ( Hydraulic oil bypass )