I have an old RepCal shower assembly in my bathroom and the washer in the pull/diverter has apparently worn out since I am unable to get any water to the shower head. My question is this: in order to
change the washer do I need to proceed from behind the valves( my bath trap access door is too small so I would have to cut a larger hole in the plaster wall)or can the repair be done by taking off the spout in other words are the mechanisms behind the wall or behind the spout?
Any help will be greatly appreciated.