Couplings won't go in, no pressure either side, balls move freely

[Z-Michigan]

So I'm having the common problem that my quick-attach hydraulic couplings won't go in, but I have tried ALL the fixes I've found in past threads here on TBN, on other tractor sites, and on youtube videos - most talk about residual pressure on one side, I have bled pressure and a bit of fluid out from both sides of the circuit literally 10+ times now, there is zero residual pressure on either side. I have inspected and fiddled with the collar and ball bearings in the female side coupler and everything moves freely with no resistance. I cleaned behind the collar to make sure it's going all the way back, and it is. There is no visible damage, dirt or corrosion on either coupler.

Now what?

My setup is a Kioti DK5010HS with the dealer-installed OEM single rear remote, trying to attach to the supplied hoses and Kioti dealer-supplied couplings for my Woodmaxx SB72 chute rotation motor. This is only the third time I've had to attach these - I do it once per winter. Year one was a mighty struggle but just finally went in. Year two was no struggle at all. Now I'm at year three and I've tried for three days without any luck.

What can I try next? Need help!

 

[RNeumann]

Three options- take the QDs off the Woodmax side, Try to connect to machine side to see if something has a bit of pressure.

Squirt all the fittings with the flex nozzle of WD-40 or something similar. Their may be a bit of something that this will flush out.

Have a neighbor or someone else with some mechanical aptitude and or gorilla grip try to push them together.

Just verifying the machine is off and you have cycled the valve in both directions with the machine off? You would need to do this prior to trying to connect the QDs.

 

[/pine]

Just curious...can you manually compress the poppets or balls etc ?...i.e., with a screw driver etc. on the females and just pushing the male ends on a flat piece of steel etc?...

 

[Z-Michigan]

Just curious...can you manually compress the poppets or balls etc ?...i.e., with a screw driver etc. on the females and just pushing the male ends on a flat piece of steel etc?...

Yes, I've actually done this repeatedly using a 3/8" punch on the females and flat surface of the blower for the male ends. No significant resistance, NO squirting oil, just a few drops of oil oozing out. Oil is clear and thick as I expect it to be at the current 25 or so F.

 

[Z-Michigan]

Three options- take the QDs off the Woodmax side, Try to connect to machine side to see if something has a bit of pressure.

Squirt all the fittings with the flex nozzle of WD-40 or something similar. Their may be a bit of something that this will flush out.

Have a neighbor or someone else with some mechanical aptitude and or gorilla grip try to push them together.

Just verifying the machine is off and you have cycled the valve in both directions with the machine off? You would need to do this prior to trying to connect the QDs.

Machine is off and cold, in two cases overnight. Loader and remote valves were both cycle repeatedly to eliminate pressure. I also tried connecting with remote valve in all three positions - no difference.

I have more strength than any of my neighbors FWIW, it's not a strength issue.

I guess I will try unscrewing a coupler from hose and seeing if it will go in as a bare coupler.

Is it possible that my hose ends (male) are at large end of tolerance, tractor fittings at small end, and cold weather shrank the tractor side enough to prevent a connection purely by mechanical dimensions?

 

[radios1]

good advice here. https://www.tractorbynet.com/forums...-hydraulic-coupling-pressure-relief-tool.html

 

[/pine]

If it is not pressure preventing them from coupling...it must be friction...Did the male ends come with the females or with the chute rotator?


I would use fine steel wool on the outside of the male ends...start with 0 and go down to 00 or 000

Be sure to remove any wool particles before connecting...

 

[ericm979]

Was it warmer when you attached them without problem last year? ag couplers have o rings in them, which will get stiff when cold. You could try gently warming the female couplers.

 

[Z-Michigan]

If it is not pressure preventing them from coupling...it must be friction...Did the male ends come with the females or with the chute rotator?
I would use fine steel wool on the outside of the male ends...start with 0 and go down to 00 or 000
Be sure to remove any wool particles before connecting...

From what I remember the male ends were purchased from the tractor dealer that installed the remote valve, but I'd have to double check.

QUESTION - the male ends have ball-shaped valves (protrusions) and the female couplings have conical tip protrusions. Is this OK? I was browsing couplings on a store site and it looks like both are common but match different brands.

Also, I tried using a Scotchbrite pad on the coupler in case there was dirt or corrosion I couldn't see, but no change.

 

[Z-Michigan]

Was it warmer when you attached them without problem last year? ag couplers have o rings in them, which will get stiff when cold. You could try gently warming the female couplers.

I've been wondering about this, but checking historical data for last year's hookup it was the same temperature or even a couple degrees colder, mid-20's.

I may try a hair dryer on it at some point anyway. I don't have any heated space I can currently put it in.