View Full Version : stuck pipe plug in drain cleanout

Pete M
December 22nd, 2005, 04:35 PM
My house was built about 1956. Typical slab cement foundation for So Cal.

I have a cast iron 1 1/2 or 2 inch clean out for a bathroom in line with the bathroom sink.

The plug is frozen in place...

I have tried a pipe wrench with a 3 foot extension over the pipe wrench but could not get the plug to break lose...was afraid I would break the pipe off actually.

Have tried heat with a propane torch...about 15 minutes several times...one time tried to cool the plug and leave the clean out hot hoping to shrink the plug a little, but no go.

Assume the propane torch may not be enough heat...

Short of cutting the wall open and the clean out off...




December 22nd, 2005, 05:44 PM
Is the plug a galvanized threaded cap?
If you have enough room ...put one wrench on the pipe,
put a second wrench on the cap.
Do you have someone to help hold the wrench on the pipe,
while you turn the other one?


Pete M
December 22nd, 2005, 06:52 PM

Thanks for the reply.

Not a cap on a protruding pipe...(I wish!)

The clean-out housing is an iron casting that is internally threaded to accept the plug...plug has a squared head for the wrench.

The clean-out housing itself is almost flush with the stucco, so no way to get a wrench on it while torquing the plug.



December 22nd, 2005, 07:55 PM
did you try hitting the pipe wrench while keeping pressure on it...get help to hold onto the 3' extension while you hit the pipewrench handle with a heavy ball peen or 4 lb. sledge.

December 22nd, 2005, 10:10 PM
Cut the pipe above and below the tee, use 2 mission no-hub couplings and switch to PVC with a wye cleanout. Use teflon thread sealant on the threads of cap, not necessary to tighten up a great deal.

You will most likely find out when you cut the piping that it is clogged badly, may be a good time to go to the next level and remove the piping and replace with PVC. smileyruno

Pete M
December 23rd, 2005, 12:17 AM
Xkavator and Dunbar,

I did try to smack the plug end with a small sledge after heating, but not at the same time that torque was being applied...hard to get any help.

There is no way to cut the clean-out off without opening up the wall...the distance between the exterior wall to to the interior and tee that connects to the drain can't be more than a foot.

Agree there must be massive corrosion behind the plug...have seen that at another clean-out that had been sealed with a rubber expansion plug some years earlier.

If push comes to shove, probably easier to open the wall on the inside under the sink...although, how in the #@$@#$ to get a sawzall at 90 degree to the pipe to cut it off....that means a REAL big hole.

Anyone have an idea on how effective SERIOUS heat...like acetylene/o2 torch hot?...plus simultaneous torque and a good series of hammer whacks?

Was hoping this was a standard problem...ie: stuck plug, no access without tearing down the house.


Pete M
December 23rd, 2005, 12:24 AM

Just re-read your post...cut the pipe above and below the TEE...duh.

Actually, as one of the uninitiated, I do not always think in the mode of
"don't waste time trying to fix the old stuff...cut it out...!"

That is probably the way to go...would avoid messing up the outside wall, only have to fix the wall inside and that would be under the sink.



December 23rd, 2005, 09:44 AM
How about an impact wrench, fitted with an appropriate size 8-point socket?


How about removing the plug destructively?

With some careful drilling and cutting, you should be able to remove the plug in pieces, without destroying the threads in the clean out housing.

Pete M
December 23rd, 2005, 03:15 PM
Dunbar and DZ,

"Destruction" is starting to sound better, or at least more satisfying.

I just have wanted to avoid starting something I can't finish...like if the clean-out/drain is actually cast into the slab and there is nothing to cut off with out breaking up the slab...have to open the wall a little to see.

Drilling out the plug may be worth trying first...then an air wrench on the weakened plug?

Hope my metal cutting drill bits will touch cast iron...I thought it was hard as glass.

Will give the drilling a try and let you know what worked.

Thanks for the ideas,


Pete M
December 23rd, 2005, 05:51 PM
DZ, etal,

DESTRUCTION RULES...! Clean-out Plug is gone! In pieces!

The plug was BRASS not cast iron like I had decided all ready...(watch out for preconceived notions of what you are working on).

Very easy to drill out the plug around the perimeter...peel/pull out the plug bung... slice the edges with a sawzall and tease/tap down the threads from the cleanout housing...slicing a little deeper as the plug threads pealed away.

The drain turned out to look pretty clean.

Put a hose down about 10 inches (as far as it goes before turning at 90 degrees...love this junk plumbing) with one of the "expanding" rubber spray/vibrator drain cleaner fittings.

Spare you all the details, but filling all basins, tubs, shower stalls with water, running the "expanding drain cleaner fitting" and draining everything at once was able to back vibrating water into the vents, and one of them finally puked out a ton of leaf litter.

Followed the same procedure with "expanding rubber hose" attatchment down all roof vents, and I think my problem of sewer gas in the shower stall is gone...(for now!).

Thanks for the help with the plug removal,