For a few years I had been waiting for someone to produce a cartridge puller for stuck or broken Delta pressure balance shower valve cartridges.
During that time I had been thinking of the best approach and one Saturday hand built the plumbing tool in my garage.
Coworkers and other plumbers that were shown the tool wanted one for themselves.
I decided to optimize the tool and make it more user friendly.
It is almost a single hand operated tool.
The tool is patent pending and in final prototyping and testing phase.
Over time and with less than ideal water conditions scale builds up on the interior of the brass shower valve body where the cartridge o-rings seal, so when the cartridges are being pulled out the o-rings are being compressed wedging the cartridge in place.
As you can see in some of the pictures the scale also builds up between the inner sidewall of the valve body and the cartridge. Sometimes the rubber o-ring sticks to the brass if the o rings are not properly lubricated before the cartridge was installed.
When normal delta cartridge removal procedures fail more pulling pressure is applied, many times resulting in the cartridge separating into two parts when the plastic locking tabs bend or break. Too often, Unrepairable damage happens to the delta brass shower valve body or connected plumbing parts at this point when various tools are used in a attempt to pry the stuck cartridge out of the valve body.
The shower valve saver has hooked forks that fit between the stuck delta cartridge and brass valve body and after being inserted the upper portion of the forks spring out and lock in place at the same time the bottom of the forks are positioned below the radius of the cartridge so that the more upward movement or pulling pressure the deeper the fork digs into the stuck delta cartridge
a cross bar and screw apply pulling pressure between the stuck delta cartridge and the bonnet ring on the valve body.
There is no pressure being applied to any piping or even the shower valve mounting brackets or connected parts.
Check out the link page for another helpful tool that is saving these valves from permanent damage.