Repair attempt of Grohe Quick Coupling

While in the middle of repairing the kitchen sink drain plumbing, I noticed a fairly significant leak under the sink.  OK, I’d failed to tighten one of the new plastic drain couplings in between repair sessions.  Fine.

But that didn’t fix most of it.  More observation found that it was coming from the source end of the flexible hose going to the faucet’s pull-out spray head.  Our Grohe LadyLux Plus faucet features a quick-connect (“Quick Coupling”) between the valve assembly and the hose to the spray.  This is a standard Grohe part, and for $30-40 I can get a replacement of the plastic end of the connection.  We have the yellow one (46 318000).  Installation is trivial.  And the leak is still small enough for a tray under the sink to catch it all.

I’m cheap, but not that cheap.  Send in a little money, get the part on the doorstep, 5 minutes work and Done.  I don’t have much problem with that.  Of course as several reviewers have commented, it’s pretty expensive for a plastic part.  And the part’s not damaged, and might be fixable.  It’s worth a try.  (So to be clear:  The motivation is maybe 20% cheap, and 80% “I can probably fix this.”)

The actual seal is an O-ring inside the plastic part.  It’s barely visible in the picture; feeling it with a probe was what convinced me of its existence.  (Just a guess, but that 25 cent part is probably all that’s needed in 90% of the repairs.)  It fits against the smooth outer surface of the male end coming from the valve.  A leak in a seal like that is often due to the crud and lime of the ages.  I’m a little surprised that no one mentions crud on the surface of the male part in discussions of repair by replacing the plastic part.

The repair plan

So the plan is to swab out the inside of the plastic part with Lime Away to get rid of the calcium deposits on the O-ring, clean the outside of the male part, and put ’em all back together with waterproof silicone grease.  Here we go.

Looking inside the plastic part, there was clearly some sort of device, but several commenters said the yellow (and green) versions don’t have a flow restrictor (though other colors do).  I vaguely recall that I might have removed a flow restrictor from the spray head end when it was all new, but I’m not sure.  And I could blow thru the plastic part both ways, so it obviously wasn’t a check valve.  But as I poked around with a Lime Away soaked Q-tip, that inside part seemed to move – and be spring loaded.  After some cleaning, it went from brown and crud-encrusted to pretty blue and white plastic parts.  And once cleaned out, it turned out to actually be a check valve!  A sensible (high end) feature – so the water in the hose doesn’t drain out when you disconnect the hose.  I rinsed it all out well, and called that done.

I scrubbed down the metal male part with a very well worn green scrubbie (couldn’t find a white one) soaked with Lime Away.  I tried to twist around the pipe rather than rubbing along its length, in case I introduced any scratches.  Unlikely, but…  It certainly looks cleaner, but the green ring of crud seems to remain.  I wonder where that hits with respect to the O-ring.

A significant part of the hope of helping it seal is a nice slathering of silicone grease.  Another Q-tip with that (on both surfaces), and it was ready to reassemble.  Done.

Fingers crossed – let’s see how it fares!  A couple of hours and a round of dish washing, and it’s still dry.  An update will follow.

Update 9/13/17: It’s been over a month, and no leaks.  I’m going to call this one a success and Done!

Update 12/13/17:  Well, not done.  It leaked some more. 🙁   I ordered the Grohe part ($34/free on eBay) and installed it 11/28/17.  I did do one more round of cleaning of the male fitting, put silicone grease on again, and the whole replacement was the 5 minute job I expected.

I put a shiny black plastic tray under it with grains of table salt in the low places.  It’s been in place for a couple of weeks now, and the salt says there have been no leaks.  I think it’s really Done this time.  (Of course I thought that before…)

About the only explanation I can come up with for why the new part worked is that the rubber in the new O-ring is newer/more live.  If that’s the case, replacing just that ring should have worked.  I probably could have gotten the old one out, if destructively.  And I could probably have managed to force a new one into place.  But I didn’t want to have to try to spec and source the part.  And with mud on my face from the first failed attempt, the 5 minutes and $34 was an acceptable cost for being Done.

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11 Responses to Repair attempt of Grohe Quick Coupling

  1. Patrick says:

    Thanks for posting this (one of us out here read your post).
    Might come in handy when I try replacing my Grohe (red) coupler in the next several months (preventive maintenance) as it approaches 11 years for the current one…

  2. Andy says:

    I’m only a few years late to the party! We have a Grohe faucet on our sink with coupling problems as well. Living in California there are water restrictions. So when the faucet was installed with unbelievably low pressure I thought it was a requirement. But my wife insisted we at least try to fix it. One call to Grohe and they sent us a new part for free. Then, just a few months later the water flow was low again. Grumble. So I called Grohe again and they sent me the coupler again. Water pressure is even better. They say it’s very unusual. I’m trying to figure out a way to clean out the coupler in case the current one goes bad. Maybe I’ll soak it in limeAway.

    • Jim says:

      Hi Andy,

      Glad you found a little camaraderie in your troubles. I looked back and didn’t have any pics of the brown mess before I cleaned it with Lime-Away. But it was at least cruddy enough that the pretty blue and white plastic was a surprise.

      Is yours cruddy looking? I’d suggest blowing thru it before/after a lime cleaning, but you might have to blow pretty hard to get the check valve open. Do you have lime scale problems on other faucets? And just in case you haven’t already done it, cleaning out the screen in the sprayer head sometimes helps a lot.

      Good luck!


  3. Bill says:

    I am wondering if one can replace the quick coupler with a fitting, a hose, and a pair of hose clamps. $38 bucks for this is rather silly.

    • Jim says:

      I don’t see any reason a hose clamp solution wouldn’t work. Tightening the top clamp might be challenging. Maybe that’s part of their design decision for a quick release.

  4. Bill says:

    Also, before one suspects the Quick Disconnect Connector itself, the sprayer head can be clogged and causing too much back pressure. Both could be suspect. When blowing through the sprayer head, it was difficult. It might be the flow restricter but it is hard to tell.
    I tried drilling out the check valve in my old quick disconnect connector. Unfortunately I ruined the inner plastic threads by drilling from both sides. Just ordered a new one from Amazon. Still takes a few days to get. Very poor design, no repairability with these Grohe faucets. I guess they only expect us to use them for 10 years and then remodel/replace the kitchen faucets.

  5. Ray says:

    Having the same problem with my quick coupling. I had a bad hose last year and ordered a new one and installed. I noticed Amazon tried to bundle a coupler with my hose order, but I stupidly declined. Now it’s the coupler time. I suspect lime/calcium deposits as it’s common in the bathroom. Going to try cleaning first with CLR.
    BTW, I stopped by the plumbing supply to see if they carried the quick coupling. They don’t but also told me Grohe faucets and parts have lifetime warranty I should be able to get it for free. We’ll see. Already paid for the hose (approx $60.00).

  6. Jeffrey says:

    I have a brand new faucet and the sprayer hose is leaking at the quick coupler. It only leaks occasionally and seeks to happen after using the faucet on low pressure and then using the sprayer. Very frustrating.

  7. Joe Fallert says:

    Can I just remove the check valve in the quick coupling? Would that would give it max flow?

    • Jim says:

      Sure, if the check valve is the cause of the reduced flow (and if you can remove it without damage!). But a clogged screen in the spray head is the usual first thing to check. And maybe check the spray head for a flow restrictor – though I don’t have clear recollection of whether I saw (and removed) one there.

      Good luck!

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