Airless spray guns will require periodic service, over time and after many trigger pulls the carbide ball at the end of the needle will wear against seat on the diffuser. This will cause paint to leak or spit from the tip when you let go of the trigger.
Replacing the needle and diffuser (gun kit) is a normal part of airless sprayer maintenance and should be done as required. Keep a spare kit in your tool box to reduce down time on the job.
Replaces Graco Part No. 287031