Repairing Bolts on a Galvanized Pipe Coupling

Apply penetrating oil to the edges of the bolt if is rusty or stuck inside the coupling. Apply oil to the edges of the nut on the bottom of the bolt as well. Wait about 15 minutes for the oil to seep onto the bolt threads before moving on. The penetrating oil acts as a lubricant, which makes it much easier to remove the bolt.

Grip the head of the bolt with a pair of pliers or a wrench. Hold the head immobile to remove the nut that holds it in place. If you do not hold the head, the bolt will turn inside the coupling but not actually loosen.

Turn the nut counterclockwise with a ratchet or wrench to loosen it. Remove the nut but do not remove the bolt yet.

Hold the coupling in place by hand if necessary. In some cases, removing the bolt might cause the coupling to fall off. You want to hold the coupling in place if this is the case. You should not have a problem unless the coupling itself has only one bolt.

Pull the old bolt out and replace it with a new one of the same size.

Hold the head of the bolt immobile with the pliers or wrench.

Turn the nut clockwise on the bottom of the bolt to tighten it. You can tighten it most of the way by hand, but you will need to use a ratchet or wrench to finish the job.