3rd Function Diverter pressure relief

[dstig1]

Some of you may recall I have had problems with pressure relief on my 3rd function diverter that I added for my Grapple. No matter what I do to relieve the pressure it is always very hard to connect and requires me to use a bar clamp to pull the fitting tight while alternating relieving the pressure back at the 3rd function button on the joystick. Big PITA. Nothing else works. And to head off the obvious question, no it is not the fluid trapped in the grapple lines heating up in the sun. I could uncouple and then immediately recouple and the issue is still there.

So this got me thinking about some method of pressure relief I could add to this. What I had been thinking was figuring out how to add a 3rd line at the connections that goes back to the tank drain (should be low pressure, right?). Then putting T valves into the pressure lines to the drain line. A quick open/close should remove all pressure and keep the fluid in the system, right? The trick is never forgetting to close those valves...or there would be trouble.

Then I went and rented a big skid steer a couple weeks ago. It had auxiliary hydraulics on it, and lo and behold had a setup that is made to drain residual pressure with 3 connections on it. A little searching online and I found this "Saturn block". It was a different model than what was on the Bobcat but same principle. Baileys has the best price I found:
Quick Couplers 237-515 Detailed Information

So I was thinking of giving that a shot, perhaps, instead of my manual version. I'd probably end up with as much in parts as this in any case. Looking for thoughts and suggestions here. I also need to figure out where I can tap into a drain line and how to do that. I assume there is one at the loader control valve block?

 

[J_J]

I have mentioned this same procedure many times in the past.

If you wiggle the lever on the tractor, before your connect, and then open the needle valve in the tee fitting, it should work every time.

Another way is to use a dummy QD attached to a piece of PVC pipe with a rag in the PVC so the fluid never builds up.

Hoses should always be stored with dummy QD up, so fluid does not drain out.

 

[dstig1]

Thanks JJ - To be clear - are you advocating the thing I was describing about adding a 3rd drain line and a manual valve? Parts start adding up quickly which is why I thought the "Saturn block" might be worthwhile. Either should work, I suppose.

Thanks!

 

[J_J]

All you need is a tee, and a needle valve.

The amount of fluid when you open the needle valve is probably no more that a tea spoon.

The only time a drain line would be important would be if you forgot to close the needle valve.

 

[1969grandpa]

When I attach or detach my grapple, I shut down the tractor, turn the key back on without cranking the engine and toggle the switch a few times, then connect or reconnect. It works for me, at least.

 

[J_J]

There are QD's that couple under some pressure and others that couple under full pressure.

 

[CalG]

You could get full pressure couplers just for this one application. If you wish to keep the matching couplers on your third as the the others, just put together a short Adapter.

Couplers with threaded sleeves that draw the joint together would integrate your present pipe clamp system.

Or there are truely Quick couplers available.

Push to Connect - Connect Under Pressure Hydraulic Couplers

Might cost less than some other solutions.

Cheers

Cal

 

[dstig1]

JJ - Gotcha. Thanks!

Grandpa - I wish mine worked that way. I do exactly as you say - It just never relieves the pressure enough to get it together by hand for some reason.

Cal - I really want to stick with the flat face couplers I have as most FEL equipment needing hydraulics will be skid steer type. I suppose the adapter section could work. I could even re-use the ones that are on the tractor for that. Still pretty pricey as many of those quick couplers are $50-100 ea for the specialty types. It's a thought. I'll look into options and see.

Thanks guys.

 

[dstig1]

Well I finally addressed this and "solved" the problem. Since it is more of a PITA in the winter with needing to swap between the bucket and plow (with hydraulic angle), this got to be too much to fight with. I picked up a pair of flat face connectors from Bailey's that were touted as "connect under pressure" type (the ones with the black paint on them, if you are looking on bailey's). I swapped those out with the ones on the tractor side, then re-pressurized and tried connecting. It was improved. You are at least able to compress the fittings now, and one of them would connect by hand, but the other would not. The backup plan was to take the standard fittings I just removed, and screw them into a couple 1/2" pipe nipples with a 1/2" 4-way cross in the middle, and one fitting on each end. This is the pressure relief tool. If you can't connect by hand, use this to relieve pressure in the other fitting by letting a few drips of oil out, and then you can make the connection. Seems a heckuva lot harder than it should be, but it works now without resorting to clamps to pull it all together, so I will call that a success, I guess.

No pics at the moment, just thought I would update on what I had to go through to make this thing connectable by hand.

 

[TomSeller]

Is 1/2" standard pipe rated to the hydraulic operating pressures we see with reliefs set anywhere from 2000 to 3000 psi? I have used it on tank lines but never the high pressure side.