# Perplexity — raw output, 2026-09-14 09:17 (+07), free plan, default model, incognito (left on; not material for this brief), one message, no follow-ups Interface Russian; answer in English. "Исследование завершено, 4 с", 35 sources (citation chips: noken, adirqual, woodies, +…). A "Видеозаписи" (videos) tab is offered alongside the answer. Captured from the page text. Chat URL kept open for review. --- A drip from the spout of a 10-year-old single-lever mixer is usually caused by a worn ceramic cartridge, not by the flexible hoses or the spout aerator. The normal DIY repair is to isolate the hot and cold water, remove the handle and retaining nut, replace the cartridge with an identical one, and test carefully. [noken +1] ## What to buy Do not buy a cartridge based only on the tap's age or appearance. Cartridge dimensions and locating tabs vary between manufacturers. Take clear photos of: the whole tap; the handle and any brand name or logo; the retaining nut and cartridge after disassembly; the underside or back of the tap, if there is a model number. Ideally, remove the old cartridge and take it to the shop. Ask in Portugal for: "Preciso de um cartucho cerâmico de substituição para uma torneira monocomando de lavatório. Pode comparar com este?" Useful terms: Torneira monocomando — single-lever mixer tap · Torneira de lavatório — basin tap · Cartucho cerâmico — ceramic cartridge · Cartucho de Ø35 mm / Ø40 mm / Ø25 mm · Chave sextavada / chave Allen — hex/Allen key · Chave inglesa ajustável — adjustable wrench · Juntas tóricas — O-rings · Válvula de corte / válvula de esquadria — isolation valve. Many replacement cartridges are 25, 35 or 40 mm, but even cartridges with the same diameter may differ in height, stem shape and locating tabs. Portuguese suppliers list all of these sizes, so take the original part or the tap's exact model information. [adirqual +2] Buy: one matching ceramic cartridge · a new cartridge seal, if not supplied · optional replacement O-rings only if the old ones are damaged · a small tube of silicone plumber's grease, if available · a cloth or masking tape to protect chrome surfaces. Do not use PTFE tape on the cartridge seal or retaining nut. Those parts normally seal with rubber seals, not thread tape. ## Tools Adjustable wrench, preferably two sizes · Allen-key set, especially 2–3 mm · small flat-head screwdriver · Phillips screwdriver, in case the handle uses a cross-head screw · pliers or slip-joint pliers · old towel · small bowl for screws and washers · torch · basin plug or stopper. Protect chrome by putting a cloth between the wrench and the tap. Avoid gripping polished parts directly with ordinary pliers. ## Before dismantling Put the basin plug in. Remove everything from under the basin. Find the two small isolation valves on the hot and cold supply pipes. Turn each valve clockwise, or turn its screwdriver slot a quarter-turn so the slot is across the pipe. Open the tap in the middle position to release pressure. Check that both hot and cold supplies have stopped. If there are no isolation valves, turn off the property's main stopcock. Do not begin dismantling while water is still flowing. Take photographs before removing anything. Put every part down in the order it came off. A dripping mixer repair normally involves cartridge replacement rather than a traditional rubber washer replacement. [woodies +1] ## Replacement steps 1. **Remove the handle** — Look for a small grub screw: on the side of the handle, behind the handle, under a small plastic or metal cap. Gently prise off the cap with a flat screwdriver, using a cloth to protect the finish. Loosen the grub screw with the correct Allen key. You usually do not need to remove it completely. Lift the lever straight up. If it is stuck, rock it gently from side to side. Do not force it sideways against the tap body. 2. **Remove the cover** — There may be a chrome cover or sleeve over the cartridge retaining nut. Unscrew it by hand, turning anticlockwise. If it will not move, wrap it in a cloth and use adjustable pliers very gently. 3. **Remove the retaining nut** — You should now see a large hexagonal retaining nut or collar. Loosen it anticlockwise with an adjustable wrench. Hold the tap body steady with your other hand. Do not twist the whole tap or the water hoses beneath the basin. If the nut is heavily scaled, apply a small amount of penetrating oil only to the exposed metal thread, wait, and try again. Keep oil away from drinking-water passages and rubber seals. 4. **Record cartridge orientation** — Before pulling the cartridge out, photograph it. Note which way the locating tabs point, the position of the stem, which side is hot and which is cold. Most installations have hot on the left and cold on the right, but do not assume yours does. 5. **Remove the old cartridge** — Lift it straight out. If it is stuck by limescale, gently work it loose with pliers or by rocking it. Do not lever aggressively against the chrome tap body. If the cartridge will not come out without significant force, stop at this stage. 6. **Clean the housing** — Wipe out loose grit and scale with a cloth. A little white vinegar on a cloth can help remove surface limescale, but do not flood the tap body with vinegar. Check that the rubber seal has not remained stuck inside, the locating holes or slots are clear, the seating surface is not cracked or badly corroded. 7. **Fit the new cartridge** — Compare the new cartridge with the old one before fitting it. The following must match: diameter, overall height, stem shape, locating tabs, seal position, outlet arrangement. Place it into the tap in exactly the same orientation as the old cartridge. It should sit flat without force. 8. **Reassemble** — Replace the retaining nut and tighten it firmly, but do not over-tighten. Excessive force can crack the cartridge or damage the tap body. Refit the chrome cover, the handle, the handle grub screw, the decorative cap. The handle should move smoothly. Do not use the handle to force a stiff cartridge. 9. **Restore and test** — Make sure the tap is closed. Open the hot and cold isolation valves slowly. Watch the retaining nut, tap body and connections under the basin. Open the tap gently. Move the lever through hot, cold and mixed positions. Close it fully and check the spout for several minutes. A few drops left in the aerator immediately after closing can be normal. A continuing drip means the cartridge is wrong, incorrectly seated, damaged, or the tap body itself is worn. ## Stop and call a plumber if Call a plumber rather than forcing the repair if: you cannot shut off the water completely; an isolation valve spins, leaks or breaks; the flexible hose or pipe connection starts leaking; the retaining nut is seized and the tap body begins to twist. --- First read: all six steps present and in order, with the fullest shop vocabulary (válvula de corte / de esquadria, juntas tóricas, three cartridge diameters) and a sensible "do not use PTFE tape" note. Stop-and-call list is short and sound. The "penetrating oil on the thread" tip is common advice; keep-away-from-water passages caveat included. Checks in the sheet.