What to Do If Your Tap Keeps Leaking After Reseating

If you’ve reseated a tap and it’s still dripping, the leak was never coming from where you thought. It’s almost always one of three things, a brass seat cracked deeper than the reseater could reach, the wrong size washer or jumper valve, or a perished spindle O-ring.

If water drips from the spout, the seat or washer is still failing. If it weeps from around the handle, it’s the spindle O-ring, and reseating was never going to fix that.

G’day, I’m Dylan from TrueFlow Plumbing and Drains. I’ve reseated more taps around the Central Coast than I can count, and this exact problem comes up constantly.

Why Is My Tap Still Leaking After Reseating?

Before you touch a spanner again, work out where the water is actually coming from. This one step tells you almost everything.

Turn the tap fully off, dry the whole fixture with a paper towel, and watch it for two minutes.

Try this now: the fingernail test

This takes five minutes and it’s the single most useful check you can do.

1. Turn the water off at the mains (usually at the water meter out the front, or the isolation valve under the sink).
2. Open the tap to drain any pressure sitting in the line.
3. Unscrew and remove the spindle.
4. Reach in with a torch and run your fingernail around the brass seat inside the tap body.

If your nail catches on anything, you’ve got a hairline crack or a pit that’s too deep to grind out. That seat needs replacing, not reseating. No amount of extra reseating will save it, and every pass takes more brass away.

If the seat feels smooth and your nail glides over it, the problem is somewhere else. Head to the fixes below.

The seat is cracked. Now what?

If the seat is gone, you don’t have to replace the whole tap.

A tap seat replacement kit cuts a fresh thread into the damaged brass and lets you screw in a new stainless steel seat. Most hardware shops stock them, they work on standard brass bodies, and they cost a fraction of new tapware. It’s the same fix I use on site when a seat is past reseating but the tap itself is still sound.

Two things to know before you buy one. It’s a one-way job, because once you’ve cut the thread the original seat is gone for good. And if the crack runs out of the seat and into the body of the tap, no insert will save it. That’s when replacement is the only option left.

Step-by-Step Fixes for a Stubborn Dripping Tap

None of this is hard. It’s fiddly, and it takes about 40 minutes if you’ve already got the parts.

To stop a tap that keeps dripping after reseating, you need to replace the secondary seals (the spindle O-ring and body washer) and make sure the valve seat is perfectly flush with a correctly sized washer sitting on it.

Here’s the order I work through.

Step 1: Replace the spindle O-ring

Slide the old O-ring off the spindle with a small flathead screwdriver. Take it to the hardware shop or plumbing supplier. Match it exactly. A millimetre out and it’ll either leak or bind.

Before you fit the new one, coat it in plumber’s silicone grease. Not Vaseline, not WD-40, not olive oil. Petroleum-based products swell and rot rubber seals, and you’ll be back doing this again in three months.

Step 2: Fit the right washer, and consider a soft-turn

Standard Australian tap washers are typically 12mm or 15mm. Mixing them up is one of the most common reasons a “fresh” washer still drips. Take the old one with you and match the diameter and thickness.

If your seat is slightly worn but not cracked, swap the standard flat washer for a soft-turn or dome-shaped washer. It’s softer, so it moulds into the little imperfections. A hard flat washer just sits on top of them.

Make sure the washer screw is firm but not cranked down. Over-tightening deforms the washer and creates a channel for water to track along.

Step 3: Check and reseat the jumper valve

Spin the jumper valve in your fingers. It should sit square and rotate freely in the housing. If it’s bent, corroded, or wobbling, replace the whole jumper valve assembly. They’re a couple of dollars.

Step 4: Fresh thread seal tape on the spindle thread

Strip the old tape off completely. Apply 3 to 4 wraps clockwise (in the direction the thread tightens) so the tape doesn’t unravel as you screw the spindle back in. Don’t bury the thread in tape. If you’re tempted to, the leak isn’t coming from the thread.

Step 5: Replace the body washer if there’s water at the base

Undo the tap body from the shroud, pull the perished washer off, fit the new one, and hand tighten plus a quarter turn with a spanner. Any more and you’ll crack it.

What if it’s a shower or wall tap?

Same seat, same washer, harder access.

The difference is you can’t isolate a wall tap under a vanity, so the mains has to go off before you start. And on older Central Coast homes, the breech behind the tile is often what’s actually failed, not the tap. If water is tracking down inside the wall rather than out of the spout, no amount of work on the spindle will touch it.

If you’ve reseated a shower tap twice and it’s still going, stop there. The cost of cracking a tile trying to get a seized wall tap out is a lot more than the call-out.

Common mistakes I see on jobs

• Reseating too aggressively. Every pass of the reseating tool removes brass. Grind too hard or too often and you end up with a seat too shallow to ever seal properly.
• Wrong washer size. 12mm washer in a 15mm seat will drip forever.
• Reusing the old O-ring. It looks fine. It isn’t. Rubber goes hard and loses its squeeze.
• Skipping the mains shutoff and trying to work off the isolation valve, which often doesn’t fully close on older Central Coast homes.
• Forgetting what caused it. Hard water is what burrs the seat in the first place. If you’re on bore or tank water, expect to be doing this more often than your neighbour on mains.

Still dripping after changing the cartridge?

Mixer taps don’t have a seat to reseat, so if you’ve been trying to reseat one, that’s the problem right there. If the handle only turns a quarter to half turn, you’ve got a ceramic disc cartridge, not a washer and seat. Same goes for most modern kitchen mixers.

If you’ve already swapped the cartridge and it still drips, it’s usually one of two things. Either it’s the wrong cartridge for that brand, since they’re rarely interchangeable even when they look identical, or the seals weren’t seated square in the body when you pushed it home.

Take the old cartridge into the supplier rather than matching it by eye. Brand and model, not “looks about right”.

How to check if you’ve actually fixed it

Don’t just glance at it. Do this:

1. Turn the water back on at the mains.
2. Turn the tap on and off firmly once, then leave it closed.
3. Wipe the entire tap completely dry with a paper towel, including the handle and the base.
4. Place a small square of dry toilet paper under the spout and wrap another loosely around the base of the handle.
5. Come back in 10 minutes.

Dry paper means you’ve sealed it. Any damp spot tells you exactly which seal is still failing, including micro-leaks that are too slow to see as a visible drip.

Is It Better to Reseat or Replace a Tap?

How many times can you reseat a tap?

Two, maybe three, in my experience. Each pass of the reseater removes brass, so eventually there isn’t enough seat left to machine flat.

If you’ve already reseated it once and it’s leaking again, or the tapware is more than 10 years old, replacement is almost always the better spend.

There’s a case for replacement beyond just stopping the drip

Griffith University put smart meters on 252 Australian homes. Every water event, traced down to the fixture it came from. One of their findings was that swapping old-style tapware for a 3-star or better fitting cut household tap water use by 12.9 kilolitres a year, around 65%.

That’s measured consumption data from real homes, not a manufacturer’s claim on a box. Changes the maths a bit, that. If your tapware is old enough to have been reseated two or three times, it’s almost certainly old enough to be costing you on every single bill, leak or no leak. The drip is just the part you can hear.

Repair or replace

The decision path

Did reseating fail?

• Is the brass seat cracked or pitted? Yes, fit a seat replacement insert, or replace the tap body if the crack runs deeper.
• No, replace the spindle O-ring, jumper valve and washer.
• Still leaking after that? Time to get a licenced plumber who specialises in leaking tap repairs, because you’re likely looking at an in-wall issue.

Quick one on the rules. In NSW you can change your own tap washers as minor maintenance. Anything in the wall, any work on the water service, or gas has to be done by a licenced plumber. If you’ve opened it up and found corroded in-wall fittings or copper that’s weeping, stop there.

How Much Will a Plumber Charge to Fix a Dripping Tap?

Most plumbers charge $80 to $150 for a tap repair. A full replacement runs $150 to $250 and up, not counting the tapware. What pushes a job to the top of that range is usually access (in-wall taps behind tiles), seized spindles, or needing to reseat multiple taps at once.

Where people get caught out is the pricing model. A lot of plumbers charge a call-out fee and then bill by the hour, so a fiddly seized spindle that takes 40 minutes longer costs you more than the quote you were given on the phone.

That’s not how I work. I charge per job, not per hour, and you get the price before I start. My service call fee starts from $99, and once I’ve looked at it you’ll know exactly what the repair costs. No meter running while I’m on my knees under your sink.

Every bit of labour is backed by our Lifetime Labour Guarantee, so if a repair I’ve done fails, I come back and sort it.

When to stop DIYing and call a plumber

Stop and call if:

• The water won’t fully shut off at the mains
• The spindle is seized and won’t budge with reasonable force
• You can see corroded or green-stained copper in the wall cavity
• The leak is coming from inside the wall or the cupboard rather than the tap itself
• You’ve replaced every seal and it’s still dripping
• It’s a mixer or ceramic cartridge tap and you can’t identify the replacement cartridge

Call Dylan on 0411 438 760. I’m on call 24/7 across the Central Coast for anything urgent.

How Much Does a Dripping Tap Add to Your Water Bill?

Less than you’d think, and that’s the wrong reason to fix it.

The Queensland government’s household water audit puts a slow-dripping tap at 3 to 27 litres a day depending on how fast it’s going. Over a year that’s somewhere between 1,100 and 9,900 litres. At typical NSW usage rates you’re looking at a few dollars up to about thirty a year on water charges. Annoying, not ruinous. Stick a measuring jug under it for an hour if you want your own number.

The interesting part is that leaks aren’t spread evenly across the street. Metering research cited in that same Griffith University study found that 2% of meters accounted for 24% of all night-time water consumption. A handful of homes are losing most of it overnight. Averaged across Australian end-use studies, household leakage works out to about 8.3 litres per person per day.

If you’ve already tried to fix a tap and failed, you’re not an average household. You’re one of the bad ones. There’s usually more than one problem going at once, and it adds up faster than people expect.

How long can you leave it?

A dripping tap can be left for weeks without disaster, but the damage it does isn’t to your bill.

Every drop that passes over a compromised brass seat erodes it a little further. A leak that starts as a $2 washer job turns into a cracked seat, then a seat insert, then a full tap replacement. If it’s an in-wall tap, that means cutting tiles. Left long enough on an older home, a constant weep inside a wall cavity causes swollen gyprock, lifting skirting, and eventually a proper repair bill. Then it’s not a tap job anymore.

If you’re on Central Coast water, there’s a catch. Councils across NSW grant leak allowances only for leaks that were genuinely hidden from view. Several also want a signed statement from a licenced plumber before they’ll grant it. A visibly dripping tap will never qualify. The allowance exists for the leaks you couldn’t have known about, not the one you’ve been listening to for six months.

Get It Sorted Properly

If you’ve worked through the checklist above and that tap is still going, it’s not you. It’s almost certainly a seat that’s past saving or something further up the line that needs a plumber’s eyes on it.

I’m Dylan, I’m a licenced and insured plumber (NSW Licence No. 457032C), Master Plumbers Association accredited, and I’ve been looking after Central Coast homes since 2018. About 65% of my work comes from word of mouth, which tells you how I like to do business.

What you get with TrueFlow:

• Upfront, per job pricing, never per hour
• Lifetime Labour Guarantee on our workmanship
• 24/7 emergency availability across the Central Coast
• 5.0 star Google rating from over 70 local reviews
• 10% discount for valid Senior Card holders

Call Dylan on 0411 438 760, or request a free quote and I’ll get back to you fast.