Third Functions Hydraulic Fittings Difficult to Engage

[RNeumann]

Heat expansion is a non issue. 99.9% of the time the fluid is warmer when in use then outside air temperature will ever be. So typically you are uncoupling and reconnecting the ends when the fluid is over outside air temps. But by the off chance the implement builds some pressure over time the simple act of uncoupling the two implement ends relieves the few drops of pressure.

Unless their is some physical limitations I’ve never had or seen an issue coupling or uncoupling that was on the implement side.

You seem stuck on this one. What process are you using to store your implements? I’m just not seeing how a few degrees of fluid temp change is cause the inability to cycle the QDs.

 

[ovrszd]

Heat expansion is a non issue. 99.9% of the time the fluid is warmer when in use then outside air temperature will ever be. So typically you are uncoupling and reconnecting the ends when the fluid is over outside air temps. But by the off chance the implement builds some pressure over time the simple act of uncoupling the two implement ends relieves the few drops of pressure.

Unless their is some physical limitations I’ve never had or seen an issue coupling or uncoupling that was on the implement side.

You seem stuck on this one. What process are you using to store your implements? I’m just not seeing how a few degrees of fluid temp change is cause the inability to cycle the QDs.

Assuming you are addressing me?

I'm not stuck on anything. I'm just offering advice.

So right now my Kubota is sitting in the machine shed with the Grapple on. It's somewhere around 30 degrees in the machine shed. I want to haul some gravel with my smooth bucket. I crank up, drive outside, uncouple the Grapple and drop it on the ground. I couple the hoses together.

Today is a sunny day with expected high of 55F degrees. This afternoon when I want to reattach my Grapple I am going to have problems. Not with the tractor. With the Grapple. Uncoupling the Grapple hoses will not release anywhere near enough fluid to release the pressure that will be there due to heat expansion. It will be so extreme that I probably won't be able to recouple the Grapple hoses to themselves. I have flush couplers. I will have a very aggravating situation.

If you've never experienced this you must rarely switch 3rd function attachments?

 

[Fallon]

My experiences match oversized's

 

[ovrszd]

My experiences match oversized's

Sucks doesn't it.....

 

[the old grind]

..I expected him to cover heat expansion. Just following the guidance (Ted) gave does nothing to solve that problem. Also coupling the hoses together does nothing to solve the heat expansion problem either.

Didn't think it was just me who noticed that right away. My fluid doesn't get hot very often, rarely warm that I can tell, I'd think the cyls might be warmer after uoing a grapple (either one) and they always seem `body temp at my level(s) of working 'em.

My experiences match oversized's

Mine too, .. so far, .. in five years of switching out a grapple(s) two-three times/year.

(Got three other FELs. One of those will also get SSQA & diverter upgrade.)

 

[npalen]

Wonder why we don't see any thermal relief valves installed on 3rd function attachments or any hydraulic attachments for that matter? They are a simple T-shaped fitting that lets a tiny amount of fluid bleed off if the pressure rises beyond a preset point. Have seen them on farm machinery.

 

[Fallon]

Wonder why we don't see any thermal relief valves installed on 3rd function attachments or any hydraulic attachments for that matter? They are a simple T-shaped fitting that lets a tiny amount of fluid bleed off if the pressure rises beyond a preset point. Have seen them on farm machinery.

Generally I expect thermal expansion pressure would be less than normal operating pressures. That would mean those would leak everywhere every time the impliment was used. Unless you are talking about a manual bleed or drain valve rather than an automatic relief valve.

 

[ovrszd]

Generally I expect thermal expansion pressure would be less than normal operating pressures. That would mean those would leak everywhere every time the impliment was used. Unless you are talking about a manual bleed or drain valve rather than an automatic relief valve.

Yeah, I doubt that thermal expansion ever gets close to operating pressure.

I've never tested this, but I suspect 100psi would prevent reattaching a coupler. Versus 2,500psi operating pressure.

 

[ericm979]

I've also seen the couplers locked up due to an ambient temp rise of a few tens of degrees. Drop the grapple at 50 degrees and pick it up at 70 and I can't get its couplers uncoupled.

I'm going to make pressure release gadgets to plug into the hydraulic implements. Each will have a coupler set, some pipe fittings and a valve. You use the valve to open the system to the outside and relieve pressure. The idea came from some thread here.

 

[ovrszd]

I've also seen the couplers locked up due to an ambient temp rise of a few tens of degrees. Drop the grapple at 50 degrees and pick it up at 70 and I can't get its couplers uncoupled.

I'm going to make pressure release gadgets to plug into the hydraulic implements. Each will have a coupler set, some pipe fittings and a valve. You use the valve to open the system to the outside and relieve pressure. The idea came from some thread here.

I think if you often have problems this is the ideal solution!!!

 

[Fallon]

I've also seen the couplers locked up due to an ambient temp rise of a few tens of degrees. Drop the grapple at 50 degrees and pick it up at 70 and I can't get its couplers uncoupled.

I'm going to make pressure release gadgets to plug into the hydraulic implements. Each will have a coupler set, some pipe fittings and a valve. You use the valve to open the system to the outside and relieve pressure. The idea came from some thread here.

I thought about trying to setup something like this at one point, although probably not with the main valve & definitely with hydraulic rated fittings not plumbing fittings. Mostly just the small bleed screw on the side. Didnt look super hard, but didnt see anything hydraulic with a finger operable bleed on it.

Picked up that tool from Ken's Bolt On Hooks & gave upon the plan.

 

[npalen]

Generally I expect thermal expansion pressure would be less than normal operating pressures. That would mean those would leak everywhere every time the impliment was used. Unless you are talking about a manual bleed or drain valve rather than an automatic relief valve.

I've seem them used on the wing fold system of farm tillage equipment where the fold may be used only a couple times a day. I'm guessing that the orifice is so small that the loss of fluid is negligible.

 

[npalen]

I'm wondering whether it makes a difference if the male disconnect is attached to the rod end or base end of the cylinders. In the case of a grapple, for example, the cylinders would probably be fully extended when disconnecting from the tractor.
If the male coupler tip is connected to the rod end of the cylinders, trying to relief thermally induced pressure on the male tip with a tool that depresses the ball or poppet would seem to be ineffective.
If the male coupler tip, on the other hand, is connected to the base end of the cylinders, the tool should relieve the pressure. Right?

I'm assuming, in the above scenario, that one male and one female is used on the grapple rather than a pair of the same gender.

Edit: My point here is that trying to relieve thermally induced pressure with a male tip on the rod end of the cylinders when they are fully extended would only relieve on the rod side but the base side would still be pressured since the piston can't move "away from the pressure".

 

[ericm979]

I thought about trying to setup something like this at one point, although probably not with the main valve & definitely with hydraulic rated fittings not plumbing fittings. Mostly just the small bleed screw on the side. Didnt look super hard, but didnt see anything hydraulic with a finger operable bleed on it.

Picked up that tool from Ken's Bolt On Hooks & gave upon the plan.

The idea is to plug the pressure release gadget's quick connects into to the implement when the implement is removed from the tractor. You'd leave it on so you can release the pressure when you're about to plug the implement back into the tractor, removing the gadget first. I don't think it needs to be made from hydraulic fittings though they'd be nicer and they don't cost much more. It's only going to see whatever pressure there is in the implement from fluid expansion in the heat. When I have removed fittings to release that pressure, it hasn't seemed like it's high pressure at all but of course there's no flow behind it. Worst case if I'm wrong will be a cracked fitting that leaks oil out of the implement as it's sitting.

You'll have to report back on how the Ken's tool works.

 

[Fallon]

The idea is to plug the pressure release gadget's quick connects into to the implement when the implement is removed from the tractor. You'd leave it on so you can release the pressure when you're about to plug the implement back into the tractor, removing the gadget first. I don't think it needs to be made from hydraulic fittings though they'd be nicer and they don't cost much more. It's only going to see whatever pressure there is in the implement from fluid expansion in the heat. When I have removed fittings to release that pressure, it hasn't seemed like it's high pressure at all but of course there's no flow behind it. Worst case if I'm wrong will be a cracked fitting that leaks oil out of the implement as it's sitting.

You'll have to report back on how the Ken's tool works.

Ah, I was assuming it would be between the cylinder & QD. No need for any real pressure rating if its between the QD & nothing.

I've used Ken's tool on my flat face connectors a couple times so far sucessfully. It doesn't catch & hold the fluid super well but it does the job relieving things. Takes 45-60 seconds maybe. Mostly winding that bolt with a wingnut on it in & out an inch or so. Not hard at all but it doesnt spin freely because of the QD poppet spring. 1 tool for every impliment beats multiple setups for each impliment.

My setup is 2 opposed single acting cylinders on the plow & a motor in the PHD. Both sides relieve when you relieve 1 side. Unless the plow is angled up to the stops... probably I've never stored it not straight. I doubt male vs female on a double acting cylinder would make much difference. My flat face connectors are 1 male & 1 female on the tractor. Both sucked equally trying to hook up an impliment. The other one was always trivial after the first one was hooked up.

 

[the old grind]

So, say the attachment has one ea male and female connector, and we want to relieve pressure in both sides/lines before reattaching.

Assemble two male ends to make a 'gender-changer'. Attach it to implement's female when disconnecting. And cap both now-male ends.

Use the tool Ken offers on both ends before you reconnect, and ...

- You've added ~$20 cost to each hydraulic attachment parked/stored (albeit once and done) and time/trouble saved may never make up for the 'price of admission'.

But ...

- One adjustment of the tool fits all the connectors with gender-changers and their two male 'storage ends'.

 

[Fallon]

Ken's tool only fits 1 gender. Pretty sure it's the male one for my flat face connectors. I'd assume the same for ag style as well.

I havent really had many issues with the ag style on the rear. Well other than being unable to connect my TnT when the impliment was in the air. That was a trivial fix though. You can also get to the male poppet with a soft hammer on the ag style as well to relieve. Much easier than the flat face style.

 

[npalen]

Just a quick thought off the top of the old noggin here: Has anyone tried ingesting a little air into the attachment prior to disconnecting? I know this sounds counter-intuitive but, for example, leave the grapple in the slightly open position prior to shutting off the engine. Then let the grapple on down with the engine off and before disconnecting the hoses. The little bit of ingested air should allow only minimal thermal pressurization, right? Probably something I'm not considering here.

 

[Thunder chicken]

I thought about installing a ball valve on my grapple hose (s). One for sure on the ‘bottom’ grapple cylinder hose. Have the QD on the ball valve. Disconnect and close the valve. Pressure trapped on back side of ball valve. I find it’s usually just the one hose that gets ‘pressurized’ beyond being able to squeeze the ball.
I have female ends on my grapple hoses and males on the loader. Colour coded zip tie keeps the order.
Big spender idea was to put a QD housing on the loader with shut off valves on each line. At least Yar way the fittings would be of the break away type for slightly easier connecting. https://ph.parker.com/us/17559/en/p...hydraulic-up-to-3000-psi-iso-5675-9500-series
That would eliminate shutting down the machine to make/break the connection to deal with the tractor pressure. Ball valves on each implement hose to isolate the QD from the rest of the ‘hose’ pressure build-up, or what I do (bad) park with my grapple open and leave it open. Maybe I’ll catch a something one day

 

[npalen]

Just a quick thought off the top of the old noggin here: Has anyone tried ingesting a little air into the attachment prior to disconnecting? I know this sounds counter-intuitive but, for example, leave the grapple in the slightly open position prior to shutting off the engine. Then let the grapple on down with the engine off and before disconnecting the hoses. The little bit of ingested air should allow only minimal thermal pressurization, right? Probably something I'm not considering here.

This one must be a REALLY DUMB idea! Just thought that its easy to introduce a little air in the system and that should eliminate thermal pressurization since there is actually very little increase in fluid volume with higher temps. The air will purge fairly quickly with a couple cycles of the grapple when its reconnected.

Or perhaps I just didn't explain the idea well enough?