Banging pipes occur when the plumbing behind fixtures don’t include an air chamber made of a vertical pipe that extends twelve inches above the shutoff valves. The air chamber cushions against the jolt that normally occurs when water flow suddenly stops, called ‘hydraulic shock’. Just recharge the air chambers.
A properly plumbed house in that era should have air chambers installed behind every faucet, but sometimes there’s a banging when you shut off a faucet.
Air chambers take the banging out of plumbing and add life to a plumbing system.
The problem is that eventually the air and water mix, disabling the air chamber. When the air chamber ‘water-logs’ it needs to be recharged.
To recharge the air chambers in a plumbing system, start by shutting off the water at the water meter. Then open up the highest faucets first, (the ones farthest from the meter) then working your way down into the basement or utility room. When you open the laundry faucet, usually the lowest faucet in the house, the whole house will drain down in to the tub. Do not forget to open the outside sill cocks and flush the toilets on your way.
Once water stops flowing, give the system fifteen minutes for the air chambers to drain.
Then refill the system by opening the valve at the meter about half way and wait for water to flow evenly out of the lowest faucet. Once it quits spitting air, shut it off and work your way up the house closing off all the faucets when they quit spitting air. Do not forget the outside sill cocks. Once everything is shut off, go back and open the main valve up the rest of the way and you have just recharged the air chambers in your home.
If the main shutoff valve leaks at the stem (sometimes from age and lack of use), tighten the packing nut under the handle just a bit. Be careful not to get over zealous, and split the nut if the packing is too hard or worn out. String packing can be added by loosening the nut, wrapping some string packing under it, and then tightening the nut back up.