The single handle faucet does not have a push/pull feature (Chateau Posi-Temp, I think). There is no cold water coming from the tub or the shower although the sink does have cold water. After reading the Moen info sheets online, I suspect it is the balance spool at the back of the cartridge which has become stuck or blocked. I was able to remove everything per the disassembly instructions until the last instruction which said, "rotate cartridge shell between the eleven and one o'clock position, grast the cartridge stem with pliers and pull out cartridge." Question #1, Where is the cartridge "shell"? The exploded picture does not reference a "shell" and #2 how hard does one need to pull? I tugged pretty good but did not want to do damage. #3 What are the chances of cleaning and replacing rather than putting in a new cartridge? The system is less than 5 years old.