How do I remove broken sewer cleanout cap?

Question

We accidentally mowed over the sewer cleanout cap. How do I remove this broken cap using tools that might be available in most households? Or by spending the least amount of money on new tools?

Answer 1

The cap is threaded into a pipe. Try the methods suggested by @FreeMan first. If unsuccessful, do this:

At each of the locations marked with a black circle, drill a pilot hole:

Obtain two suitable sheet-metal screws, similar to this:

Drive a screw into each location, leaving the screw head a bit proud of the surface of the cap.

Place a metal rod or piece of flat stock diagonally across the cap, over the broken part. The rod/flat stock should extend past the screw several inches on each side.

The left side of the rod/flat stock should be above the left-side screw (as shown in the photo); the right side of the rod/flat stock should be below the right-side screw. You may have to sand or cut the the ridges (where the cap broke) so that the rod/flat stock lays right on top of the cap.

Turn the rod/flat stock counter-clockwise. The cap should unscrew from the pipe into which the cap is threaded.

(first image from the question; second image from images.google.com)

Answer 2

Assuming you can't just grab hold of what's there and unscrew it by hand, I would use a long, sturdy screwdriver or pry bar^*, insert it through the hole at an angle from the corner furthest from the camera to the corner closest to the camera and unscrew.

I'd choose that particular angle because the way it's broken, there's a hooked, vertical edge into which the screwdriver/pry bar should catch to give you a good grip. None of the other 3 corners seem to have anything for your lever to catch against, and some of the corners look like they're ramps, just primed to cause it to slide out.

If you don't have anything that could be used as a pry bar or lever, you could use a pair of locking Vice Grip™ type pliers and lock the jaw on the inside of the corner closest to the camera. Once you've got it good and locked on there, you should be able to unscrew it with no issue.

If you need to pick up a tool, you're not wasting a trip, you'll need to pick up a new cap, too.

^* Or any type of sturdy rod that you may have available. You'll probably want it to be metal, as wood might break, depending on how tightly the cap is screwed on, and plastic, unless it's very stiff, will likely just bend.