how to replace flexible coupling when you can't move the pipes?

Question

I have a leaking flex coupling in a vertical line. The leak is due to a small hole in the coupling. It is the kind of coupling with rubber and two metal clamps, one at each end. I've loosened the metal bands on the old flex coupling to try to replace it, but it won't budge after the bands are removed. So, I assume I would need to cut the rubber coupling to remove it. However, the pipes that it connects also won't move, and I'm guessing that there will be little gap between the pipes to install a new coupling after I remove the old coupling. So, how do I get a new flex coupling in there?

Currently, the options I see are (1) cut the old coupling out, and hope I can somehow force a new coupling in with the small amount of available space. But I'm not optimistic I'll be able to do it. The vertical line leaving the coupling then goes into a 90 degree elbow and runs only for a very short distance, about a foot, before entering the ground. So I don't think I'll have much play to make space to get a new coupling in there. (2) cut the old coupling out, cut the elbow off, attach a new coupling to a new piece of pipe, attach an elbow, then glue things back together. But that seems like more work than needed to just replace a coupling. (I need some kind of coupling as it adapts from 1 1/2" to 1 1/4") (3) Is there a way just to fix a small leak in a flexible coupling? Some kind of glue that could go in the hole? This coupling is outdoors in a sump pump, so a small leak is no issue and will not cause damage.

Other ideas?

Answer 1

If you can't move the pipe, you cut the pipe so you can pull a section out, and repair it with 2 new flexible couplings - one for the original spot, and one for the new cut spot.

However, if it's connected to a sump pump, you can generally:

• Remove the blocks the sump pump should be sitting on in the sump to drop the pump and that part of the pipe a few inches so the pipe can be pulled out of the coupling.

• Or unscrew the pipe from the pump (with the coupling loosened) and then pull it to the side and down.

• Or just rotate the whole sump pump and pipe assembly so the new coupling can be slid onto one pipe (all the way) then rotate it back so it can be slid onto the other pipe (halfway) and tightened.

As for getting the old "hardened and stuck" coupling to move, try a wooden block and a hammer (set the block next to the pipe on the end of the coupling, and hit it with the hammer, moving around the pipe) before whipping out the knife or saw. Less likely to damage the pipes and make a leak point for the new coupling.