Quick Answer:
If the leak got worse after tightening the mounting ring, the mounting ring or gasket was likely distorted or misaligned. Shut off the water, loosen the ring, re-seat the assembly, and inspect the gasket and surfaces for damage. Tighten gradually and evenly when reassembling and test for leaks before finishing the job.
Why This Happens
A mounting ring compresses a gasket or flange to seal the sink or disposal to the countertop. If you apply too much force or tighten unevenly, the gasket can warp, the ring or flange can bend, and sealing surfaces can shift so water finds a new path. This is more common right after adjustments or repairs, and can also follow related work like Disposal leaks after power surge or installations such as Leak after replacing sink.
Step-by-Step What to Do
1. Turn off water and clear the area
- Shut off the supply to the sink (or the main supply if needed).
- Place a bucket under the sink and remove items from the cabinet so you can work safely.
- If the disposal is involved, disconnect power before touching connections.
2. Loosen the mounting ring just enough to relieve pressure
- Loosen the fasteners a few turns to remove excessive compression.
- Loosen slightly and re-seat the assembly if the ring was over-tightened and warped the gasket.
- Check that the sink flange and gasket sit flat and centered over the drain opening.
3. Inspect the gasket and mating surfaces
- Look for cracks, tears, flattened areas, or debris on the gasket.
- Check the metal or plastic mounting ring for bends or uneven spots.
- Clean both mating surfaces so the gasket can seal properly.
4. Reassemble and tighten evenly
- Seat the gasket and flange in position, hand-thread fasteners if present.
- Tighten a little at a time, alternating points if there are multiple clips or screws so compression is even.
- Do not overtighten—snug and even is better than very tight.
5. Test and adjust
- Restore water and watch for leaks while someone else runs the faucet.
- If a small leak appears, tighten a bit more evenly or reseat again if needed.
- Replace the gasket or mounting ring if damage is visible and leaks persist after re-seating.
What Not to Do
- Do not crank down the mounting ring with excessive force; it can warp the seal surfaces.
- Don’t try to mask a persistent leak with copious sealant—this hides the real issue and can make future repairs harder.
- Avoid working with the water on or the disposal powered; that risks injury and more damage.
When to Call a Professional
- If you cannot stop the leak after loosening, re-seating, and replacing a damaged gasket.
- If the mounting ring or sink flange is cracked, bent, or corroded and needs replacement beyond basic parts.
- If there is extensive water damage to cabinetry or sub-counter materials, or if you suspect structural issues.
Safety Notes
- Turn off water and power before working under the sink.
- Wear gloves and eye protection to avoid cuts and chemical exposure.
- Support heavy components (like a disposal) before loosening the mounting ring so they don’t drop.
Common Homeowner Questions
- Why did the leak get worse when I tightened it?
Over-tightening can distort the gasket or bend the ring so sealing surfaces no longer match. - Can I reuse the same gasket?
Yes if it looks undamaged and springs back; replace it if it’s cracked, flattened, or cut. - How tight should the mounting ring be?
Tight enough that the gasket compresses evenly and stops leaks—snug and even, not extreme force.