We've got a Kohler Mazz® kitchen faucet, model K-R72511-SD-VS, that we love the look and feel of. We've had it long enough for a number of things to go wrong, including a broken sprayer head switch and a leaky quick connect connector. We've replaced parts and fixed things and it's reached the point that notes on the internet would be helpful (at least to future me, maybe others), so here we are.
There's a faucet service parts diagram under the "Installation & Service Parts" heading; someday I'll go save the SVG for posterity and add it here.
The replacement head part number is 1235124 and cost $50 in Jan 2023. It's a straightforward repair; you'll want a set of regular pliers or channel locks plus a rag or small piece of cloth. You won't need to shut off the water under the sink.
- Pull the sprayer head out and you'll see it screws into a chrome-plated connector at the end of the hose.
- Wrap the rag around that connector to keep the pliers from marking it, then hold it tight with the pliers and gently unscrew the sprayer head.
- Screw the new one in the same way and you're done; it only needs to be hand tightened and shouldn't leak.
For ours, this turned out to be the two o-rings on the brass connector attached to the copper line at the bottom of the faucet. Those are standard 5/16" inner diameter o-rings that I picked up at my local hardware store for 49¢ each. Peel the old ones out, put on the new ones, and the quick connect connector should snap into place and seal nice and tight.
Any time we've had flow issues, it seems like it's inevitably something that came in through the water line and got lodged ... somewhere. There are a couple of places worth examining.
Rub you finger across all the small rubber nibs where sprayer jets come out; this sometimes dislodges very small bits of stuff that got through all of the filters.
There's probably a way to remove the aerator and clean it; we've never needed to yet.
The body of the quick connect connector has two NeoPerl DW14 check valves to prevent backflow pressure from damaging the faucet. Unfortunately, if something gets into the water line, it can get trapped in these, which can reduce flow and also allow backpressure to build up.
Luckily, it's pretty easy to clean them as long as you're comfortable turning off the water and disconnecting the quick connect connector.
- Have a towel; a small bowl; a toothpick or other soft, pointed probe that won't scratch plastic; and something long and thin like a standard wooden #2 pencil. I also had a very thin, 4-inch long flathead screwdriver at hand.
- Turn off the water to the faucet, then open it by moving the faucet handle to the "on" position. No water should be coming out.
- Disconnect the quick connect connector and drain the hose into the bowl. Having the faucet open should drain it well and quickly.
- Wipe the o-ring'd end of the connector with the towel to help it not drip on you later. Drop it below to catch any drips.
- If you look at the base of the white plastic connector, you'll see there's a place it screws together, with one end on the hose. Unscrew it at that point, leaving the part attached to the hose in place.
- If you look into the long connector part you just unscrewed, you should see the bottom of the bottom-most valve; it looks like a plus-sign inside a circle (good pictures at Di Vapor).
- Gently! with the tip of the pencil or flathead screwdriver pull it out. It's not screwed in or held in by anything other than the pressure of the o-ring at its top; it's normally held in place by the bottom of the connector that's currently on the hose.
- Using the eraser end of the pencil, push the top-most valve out.
- Clean the valves using the toothpick, pushing gently down on the center plunger from the top (o-ring) end and using the toothpick to degunk anything lodged there.
- While you've got them out, wrap a bit of facial tissue around the pencil and use it to swab the interior of the connector clean.
- Gently! slide the valves back in with top (o-ring) facing the connector snap and bottom (plus-sign) facing the threaded bit. Make sure they're in snug to each other.
- Screw the connector back together. I was able to hand-tighten and get it snug, so no tools required there.
- Snap the connector back to the bottom of the faucet.
- Turn the water back on and observe to be sure you don't see any leaks. If you do, note where the leak is, turn it off again, and tighten whatever's leaking.