As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TROUBLESHOOTING PILOT'S SIDE STATIC SYSTEM FOR LEAKS, FOUND THE ALTERNATE STATIC SOURCE CONTROL VALVE WAS NOT THE PROPER LEARJET VALVE. THE VALVE THAT WAS INSTALLED WAS A HARDWARE STORE VARIETY NATURAL GAS VALVE. IT WAS FOUND THAT THIS VALVE LEAKED. IT IS UNKNOWN WHY THIS VALVE WAS INSTALLED. THE VALVE WAS REPLACED WITH THE CORRECT PART.