Removing the failed hot limit stop ring from the kitchen faucet reminded me of a fix I’d done a few months ago. The faucet spout eats the O-rings sealing it to the column rising out of the sink, as evidence by the far-too-many replacements I’ve installed over the years.

The O-ring replacement kit includes a pair of nylon (?) split rings which should provide bearing surfaces for the spout, but the upper ring sits in a groove putting its OD almost flush with the column:

This may be tolerance creep or just a design screwup, but the spout squashes the O-ring much more than (IMO) it should and wears it out entirely too soon.

This time around, I cut a strip of 0.4 mm thick polypropylene (from the Big Box o’ Clamshell Packages) long enough to wrap around the column and narrow enough to fit inside the groove, with the split ring holding it in place. The strip expands the ring’s OD to just barely fit inside the spout, so the spout now bears mostly on the ring, not the O-ring.

Despite measuring the groove OD and the spout ID, I had to cut-and-try several strips to find the proper thickness. Your mileage will certainly differ.

The spout now turns smoothly and freely, without leakage. We’ll see whether the new O-rings last longer than before.

During an evening KP session, the kitchen faucet handle jammed at the clockwise (hottest) end of its travel and refused to turn; it continued to move vertically and I turned off the water. This had happened before, so I knew roughly what to expect:

The pointer on the red hot limit safety stop ring should be aimed just right of the front screw, at the 0 position producing maximum hotness. The scale reads backwards, perhaps in units of increasing safety.

In that position, the ring prevents the valve core from turning counterclockwise, which explains the symptoms. With the water turned off (at the ball valves in the basement) and the valve stub tilted vertically, the ring popped loose (it shouldn’t move on its own) and exposed the problem:

Neither Mary nor I recall applying that much force to the handle, but ya never know.

The flanges protruding from the stem prevent you from removing the ring, but a pair of small diagonal cutters will chop right through the plastic. If you’re one of the six people depending on the limit stop to keep the water temperature under control, you probably don’t want to cut the ring out; I have no suggestions on how to repair it.

It’s obvious the splines won’t ever be the same again:

The ring has two sets of splines and they’re both wrecked:

With the ring out of the way, it’s easy to see the trunnion shaft has moved leftward:

There’s essentially no clearance between the shaft and the ring, so it was rubbing against the ring, as evidenced by the red debris left behind when I tapped it to the far end of its travel:

Reassemble in reverse order and it works fine again.

I expect the shaft will resume moving leftward and eventually jam in the notch, probably after abrading the white plastic, but I don’t see how to lock it in place.

The latest in a continuing series of annoyances from our American Standard kitchen faucet: it became increasingly hard to turn it on with the handle all the way to the left in the “hot” position. Bear in mind this valve is less than a year old and I replaced its predecessor two years before that, after maybe a decade of service from the OEM valve.

Pulling it apart revealed the problem, which requires a close inspection.

The view from the “cold” side:

And from the “hot” side:

See it?

The valve handle stem pivots on the 4 mm shaft passing through the black “engineering plastic” shape inside the red hot-limit ring. This top view shows the overall layout:

The shaft has worked its way leftward, toward the “hot” side, until it bumped into the limit ring. The right end of the shaft hasn’t come completely out of the inside of its pivot, but it’s apparently gone far enough to stop pivoting freely.

This may also explain how the previous hot-limit ring worked loose: the misplaced shaft applies torque to the limit ring as we move the lever to the “cold” side. I don’t know how the ring worked its way upward from its positioning notches. Overall, it seem plausible.

Installing a new valve isn’t going to get us a better design, so I must figure out how to keep the shaft in the middle of its travel. Perhaps replacing it with a slightly longer shaft will work around the problem, because it simply can’t slide in either direction.

Loosening the three screws holding the cartridge down (and applying pressure against the seals) reduces the force required to move the faucet, even with the shaft in the wrong position. This suggests the valve body distorts slightly, so I loosened all three and (roughly) equalized their torque; the valve isn’t leaking and we’ll see what happens next.

The  ceramic valve core from our kitchen faucet certainly qualifies for a spot on the bottom flange of the I-beam across our basement serving as a display case / collection area for shop curiosities, mementos, and the like. I am, if nothing else, a creature of fixed habits, because the spot where the core belonged already had one:

American Standard Ceramic Faucet Valve Cores – old vs new

The core on the left dates back to the 2016 replacement, so they’ve apparently decided plastic will work fine for the handle socket.

Having the ceramic core fail after two years suggests the manufacturing process needs attention, though. I can still wring the slabs together, though, and they’d need a drop of oil to serve as bearing surfaces.

The O-rings on the spout of our American Standard kitchen faucet wore out again; having described that repair many times, there’s no need to say much more about it. I didn’t want to get into this repair while thinking about the hot limit problem, but I did check to make sure the box under the sink had some O-ring replacement kits.

A bench vise with soft jaws holds the spout while you remove the escutcheon ring retainer:

Kitchen faucet spout – in vise

Basically, just tap around the ring with a long drift punch and it’ll eventually fall out onto the reasonably clean rag below it.

The interior of the spout before cleaning shows why you should never look into your plumbing:

Kitchen faucet spout interior – before

After a few hours in a white vinegar bath and a few minutes of scrubbing with a ScotchBrite pad:

Kitchen faucet spout interior – after – 1

Another view:

Kitchen faucet spout interior – after – 2

Obviously, you could do better, but it’s hard to get excited about the last few nodules. For whatever it’s worth, the nodules grow despite our water softener; I have no clue what’s going on in there.

A few wipes of silicone grease, reassemble in reverse order, apply a firm shove, and it’s leakless again. For a while, anyhow.

For the second time in a few months, the kitchen faucet handle stopped moving all the way to the left and the spout stopped dispensing hot water. The last time I did nothing and, after a few days, it resumed normal operation. Having had a while to think it over, this time I removed the handle and saw exactly what I expected:

American Standard faucet – hot limit ring

The installation manual has a useful diagram:

American Standard Elite 4453 4454 faucet – hot limit stop diagram

The red ring (the “hot limit safety stop”) fits into one of eight click-stop positions; the photo shows it in position 5, with 0 being just to the right of the bottom screw and 7 just below the horizontal notch across the middle.

The dark gray plastic feature inside the ring connects the metal handle (the out-of-focus silver stud aimed at you) to the valve assembly. The two lugs sticking out to its left and right bump into the inward-pointing red lugs as you rotate the handle leftward = clockwise = more hot. With the ring set to the 0 position, the red lugs overlap similar lugs molded into the light gray valve body that limit the rotation in both directions.

Observations:

• You must pry the red ring upward to disengage the splines locking it into position
• The gray lugs impose a hard stop in the counterclockwise direction = cold
• There’s no upward force on the ring for any reason that I can imagine
• We don’t pound on the faucet handle, so there’s no shock loading

I have no idea how the red ring could disengage its splines and move counterclockwise by five clicks all by itself.

I reset it to 0, reassembled the faucet with a dot of penetrating oil in the set screw, and it’s all good.

We’ll see how long that lasts …

It seems everybody must disassemble an American Standard kitchen faucet to replace the spout seal O-rings, as my description of How It’s Done has remained in the top five most popular posts since I wrote it up in 2009.

About two years ago, I replaced the valve cartridge with a (presumably) Genuine Replacement; unlike the O-rings, the original valve lasted for nigh onto a decade. A few weeks ago, the replacement valve began squeaking and dribbling: nothing lasts any more. Another (presumably) Genuine Replacement, this time from Amazon, seems visually identical to the previous one and we’ll see how long it lasts.

I always wondered what was inside those faucets and, after breaking off the latching tabs in the big housing to the upper right, now I know:

American Standard Faucet – disassembled

You get a bunch of stuff for twelve bucks! The stainless steel valve actuator is off to the right, still grabbed in the bench vise.

The valve action comes from those two intricate ceramic blocks with a watertight sliding fit:

American Standard Faucet – ceramic valve parts

In fact, you (well, I) can wring the slabs together, just like a pair of gauge blocks. That kind of ultra-smooth surface must be useful for some other purpose, even though I can’t imagine what it might be…