# Claude — raw output, 2026-09-14 09:17 (+07), Sonnet 5 / Medium (the free plan's verified default, run from a Max account), one message, no follow-ups Interface English. "Planning a clear step-by-step repair guide." then answered in about 30 seconds as prose plus an eight-step **stepper widget** (one step at a time with Next, or "View all steps"). No web search. Captured from the DOM with the widget expanded. Chat URL kept open for review. --- A dripping single-lever mixer is almost always the cartridge (the sealed unit inside that controls flow and mix) wearing out. Good news: it's one of the more DIY-friendly repairs, since you're replacing one part rather than fixing anything precisely. ## What to buy - A replacement cartridge that matches your tap. This is the tricky part — cartridges aren't universal. Take a photo of your tap (and ideally remove the old cartridge to bring with you) to the shop and ask for "um cartucho para torneira misturadora monocomando" (a cartridge for a single-lever mixer tap). If they can't match it from the photo alone, bring the old part in — most Portuguese hardware/plumbing shops (loja de material de canalização, or a well-stocked Aki/Leroy Merlin) can cross-reference it by brand and size. - Plumber's grease or silicone grease ("massa de silicone" / "lubrificante para vedantes") to grease the new cartridge's O-rings. - A couple of spare O-rings if the shop sells them for your cartridge (often bundled with it). - PTFE tape isn't usually needed for the cartridge itself, but handy to have. ## Tools - Adjustable wrench or the specific spanner size for your tap's retaining nut (often the tap's own cap is unscrewed by hand or with a wide flat wrench) - A flathead screwdriver and/or hex/Allen key (to remove the lever handle — check underneath or the side of the lever for a small grub screw, sometimes hidden under a decorative cap) - A small container or towel for water that dribbles out - Optional: pliers, in case anything is stuck ## Steps (stepper widget, 1–8) 1. **Shut off the water** — Look under the basin for two small shut-off valves (one hot, one cold) on the pipes feeding the tap. Turn both clockwise until they stop. If there are none, you'll need to shut off the main water supply to the flat/house instead. 2. **Open the tap and drain it** — Lift the lever to open position and let any remaining water in the pipes drain out into a cloth or basin. Leave it open for the rest of the job so you're not working against trapped pressure. 3. **Remove the lever handle** — Find the small screw holding the lever on — usually hidden under a plastic cap on top or side of the lever that pries off with a flathead screwdriver. Unscrew it (Allen key or small screwdriver) and pull the lever straight up and off. 4. **Remove the retaining cap and nut** — Underneath the lever you'll find a decorative cap or collar, then a nut or ring holding the cartridge in place. Unscrew this by hand or with an adjustable wrench, turning counter-clockwise. 5. **Pull out the old cartridge** — Lift the old cartridge straight out. It may be stiff — wiggle it gently rather than forcing it sideways. Note its orientation and the position of any small tabs or notches, since the new one must go in the same way. 6. **Fit the new cartridge** — Grease the O-rings on the new cartridge lightly with silicone grease. Insert it in the same orientation as the old one, lining up any tabs with the notches in the tap body, and press it firmly into place. 7. **Reassemble in reverse** — Screw the retaining nut back on (snug, not over-tightened), replace the decorative cap, refit the lever and its screw, and snap the small cap back over the screw. 8. **Turn the water back on and test** — Close the tap lever first, then slowly reopen the shut-off valves. Check underneath for leaks at the joints. Run the tap through hot, cold, and off a few times, and check that it fully stops dripping when closed. ## When to stop and call a plumber (canalizador) - There are no shut-off valves under the basin and you're not comfortable shutting off the main supply - The retaining nut or cartridge is corroded/seized and won't budge without excessive force (forcing it can crack the tap body) - After reassembly it still drips, or now drips somewhere new (usually a bad O-ring seat or a cartridge that's actually the wrong one) - You find the shut-off valves themselves are seized or leaking when turned — that's a separate job - The tap body itself is cracked or the threads are stripped Realistically this is a 20–30 minute job once you have the right cartridge in hand, and the hardest part is matching the part — so don't skip bringing the old cartridge or a clear photo (including the brand name if visible, often stamped on the tap base or lever) to the shop. --- First read: all six checklist steps present and in order; step 2 explicitly leaves the tap open for the job; step 8 closes the lever before reopening the valves. "Um cartucho para torneira misturadora monocomando" is fine Portuguese; "canalizador" is the right word for the plumber. Stop-and-call list includes the seized isolation valve. No sizes (35/40 mm) and no price. Checks in the sheet.