Culligan Water Softener Issue

We have a 7yr old Culligan Silver Series and recently we noticed a decreased in water pressure when opening multiple faucets. The pressure is restored once we bypass the water softener. We noticed that water is constantly dripping from the drain hose. We inspected all the pistons and the seal pak and they look good. We clean the eductor and regreased everything again. But the water pressure has not been restored and the leak continues. We also noticed some particles in our water. Should we try spending the $150 to change the seal pak? Could this be a resin issue in addition to the leak? Thank you in advance for any help.