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Discussion Starter · #1 ·
This topic comes up frequently, so I figured I'd do a thread on this.

If you have hydraulic quick disconnects/couplers (QD's, QC's) on your machine that leak while CONNECTED, often replacing the O-ring in the female coupler will fix that. A small dental pic or a "pick and hook" set from places like Harbor Freight, Amazon, and other tool suppliers. They are usually under $10.00

If they leak while DISCONNECTED, then the only real answer is to replace the coupler, they are not rebuildable.



Here are the common sizes used, they are available from MANY sources:

For 1/4" ISO 5675 "AG" style couplers:
Size = 113
Durometer = 70A
Material = Buna N

For 1/2" ISO 5675 "AG" style couplers:
Size = 117
Durometer = 70A
Material = Buna N

If you are not sure what size couplers you have, you can look at the downloadable charts and/or the tables we have on our website:

 

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Thank you Kenny. At the moment I don't have this problem but I will try to keep it mind for when I do.
 

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Thanks for posting
 

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Great info.....now to find them.
 

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When looking for o-rings, PAY ATTENTION TO MATERIAL !!! Buna N, often referred to as Nitril will work in a petroleum based fluid system, such as a hydraulic system. Many general hardware stores or plumbing shops carry epdm o-rings designed to be used in water based fluid systems, like you house water, and turn VERY soft in a few weeks after contacting a petroleum based fluid. Do NOT use epdm for hydraulics! Before purchasing, verify material!

Durometer (hardness) is not too critical but a higher number could mean difficulties in connecting.

For a simple round ring, there ARE things to be considered! Bob
 

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Here are the common sizes used, they are available from MANY sources:
Thanks for posting but I'll probably still call ya. 🤣
 
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Great to know and thanks. Do you have a spec for the 3/8 coupler, I have a 2520 w/PB, and as one 1/4 QC for the FEL started leaking when I added the third function I plan on replacing all the old seals - FEL and PB.
 

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Discussion Starter · #9 ·
Great to know and thanks. Do you have a spec for the 3/8 coupler, I have a 2520 w/PB, and as one 1/4 QC for the FEL started leaking when I added the third function I plan on replacing all the old seals - FEL and PB.
Sorry, if I had that info I would have posted it. 3/8" are hardly used anymore
 

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Discussion Starter · #10 ·
More cool coupler stuff from a recent tour @Tractor Tim took at the Faster Factory in Italy:

 

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Great to know and thanks. Do you have a spec for the 3/8 coupler, I have a 2520 w/PB, and as one 1/4 QC for the FEL started leaking when I added the third function I plan on replacing all the old seals - FEL and PB.
Is it possible for a male connectorp to be damaged without visible damage, but cause a connected leak? Changed the female seal. Still dripping under pressure.

Sent from my SM-N976V using Tapatalk
 

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It's possible, but not probable or normal! Could be hose(s) are a little short or putting pressure on connector o-rings side to side compressing o-ring to much on one side and leaking on other side. Another possibility is o-rings are installed on the wrong side of the back-up rings...if your connector has them. System pressure should push against o-rings which then push against back-up rings. Back-up ring will be a normally white hardish plastic ring with a convex surface on one side, facing the o-ring, and a flat surface on the other side, facing the flat surface in the groove. A third possibility is the male connector is just plain warn from removing/installing. Bob
 
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It's possible, but not probable or normal! Could be hose(s) are a little short or putting pressure on connector o-rings side to side compressing o-ring to much on one side and leaking on other side. Another possibility is o-rings are installed on the wrong side of the back-up rings...if your connector has them. System pressure should push against o-rings which then push against back-up rings. Back-up ring will be a normally white hardish plastic ring with a convex surface on one side, facing the o-ring, and a flat surface on the other side, facing the flat surface in the groove. A third possibility is the male connector is just plain warn from removing/installing. Bob
Which goes first? Back up plate to inside of female or outside of female coupling? Was a bit surprised when that came out with the old o ring.

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I'd install inner, nearest the poppet, back-up ring first, then o-ring, then outer back-up ring, then o-ring. The main thing to watch is which way the curved surface on the ring faces. Pressure should push the o-ring into the curve surface and then push the o-ring and the back-up ring against the flat side of the groove.

If by "goes first" you referring to wears out first, I'd guess the outer one first as the male coupler isn't aligned exactly correct. Once in enough to get to the inner ring, alignment of the male plug is just about textbook perfect! Bob
 
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