Replace o-ring on Ideal Standard 'Silver' Bidet

Question

Ideal Standard 'Silver' Bidet has this little swivelling nozzle on the spout. The o-ring on this deteriorated over time, leading first to leakage around the nozzle, then it came off all together. Photo shows the various parts:

• A: Remaining end of tap; note bulbous shape.
• B: Inner part of swivelly nozzle (bottom view).
• C: Inner part of swivelly nozzle (top view).
• D: Outer part of swivelly nozzle with worn-out o-ring.

I have a heap of replacement o-rings of different sizes, but I can't figure out how to put it back together. Clearly B/C screws together with D. I surmise (perhaps incorrectly) that the o-ring serves, not only to provide a water seal, but also to physically retain B/C on the bulbous part of A. But there's not much of a lip inside C to retain the o-ring. And how to put the pieces together? I can preinstall the o-ring over A, but can't then persuade it into C. I can preinstall in C, but when I try to push it on A, the o-ring just slides down inside A, refusing to ride over bulbous A.

Any ideas?

Answer 1

This is the exploded view (from here)

From here, it appears the replacement parts numbers are:

• Flow straightener (37) - A910212
• Swivel (37a) - E960577AA
• Aerator (37b) - A910287

Answer 2

I am assuming item d) has female threads on both ends. normally, the head has an aerator at one end (this might be c), and an orbital socket at the other. the assembly typically works by pinching the ball between two nylon cup washers, and the threaded ring provides compression to seal the whole thing up. however, this usually means one of the retainers and one half of the nylon cup assembly are above the ball. this means you have to remove the ball from the faucet to remove the upper seal and compression ring. I think your upper compression ring may have failed, letting the assembly come off. you probably have an allen key socket in the ball (for removal), but it could just be a standard thread on ball. just remove, buy a new assembly, and reinstall.