Question
I was removing my sink trap to clean it.
While doing that, I broke the pipe at the bottom of the drain assembly.
Now I need to replace the drain assembly.
The big nut at the bottom is loose.
But the drain pipe will not break free.
I have tried pushing it.
I have tried using a wrench.
I have even tried hammering it.
Nothing seems to move.
Answer
Stop hammering the drain pipe.
The pipe may be stuck from old putty, rust, corrosion, or dried sealant.
Forcing it can crack the sink or damage nearby plumbing.
A stuck drain assembly is common on older sinks.
The bottom nut may feel loose, but the upper drain flange can still be sealed tight.
Old plumber’s putty can harden like glue.
Metal parts can also bind together over time.
First, place a bucket under the sink.
Then remove any loose trap parts.
Wear gloves and eye protection.
You can review basic sink drain parts at Family Handyman.
Next, spray penetrating oil on the threads and joints.
Let it sit for at least 15 minutes.
Longer is better for old metal parts.
Do not use too much force right away.
Hold the drain body from above if possible.
Then turn the lower section from below.
Use two tools when needed.
One tool holds the drain still.
The other tool turns the stuck part.
If the pipe still will not move, cut it out.
This is often safer than hammering.
A small hacksaw or oscillating tool can help.
Cut only the broken drain piece.
Do not cut the sink.
If this is a bathroom sink, the part is often called a pop-up drain assembly.
If this is a kitchen sink, it may be a basket strainer.
The replacement part must match the sink opening.
Helpful repair guidance is also available from This Old House Plumbing.
After removal, clean the sink opening well.
Scrape away old putty.
Wipe the area dry.
Install the new drain with fresh plumber’s putty or the supplied gasket.
Follow the part instructions.
Tighten the new nut firmly.
Do not overtighten it.
Overtightening can crack parts or squeeze out the seal.
Reconnect the trap.
Then run water and check for leaks.
If the drain is badly rusted, call a plumber.
You should also call one if the sink is cracked.
A stuck drain can turn into a bigger repair fast.
The key is simple.
Loosen, soak, hold, twist, and cut only if needed.
Do not keep hammering the drain.
I’m Chris Mayer, writing for Plumbing 101.
