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.