Delta Monitor 1998, New shower cartridge drips

[callbr549]

My Delta Monitor shower, circa 1998, was dripping. I replaced the cartridge with a new Delta 1300/1400 replacement kit (about $50 at the local hardware). Now the new one drips worse than the one I replaced. Any ideas how to fix this?

Rob

 

[Terry]

Are you sure the rubber seals were seated at the back before pushing the cartridge back in? We've all done it.