As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) LT MLG FAILED TO RETRACT ON FIRST TAKEOFF POST REPLACEMENT OF SECONDARY SELECTOR VALVE. THE ACFT WAS BROUGHT INTO THE HANGAR PLACED ON JACKS AND FAILURE WAS ISOLATED TO THE NEWLY INSTALLED SECONDARY SELECTOR VALVE. A REPLACEMENT VALVE WAS ROBBED FROM ANOTHER ACFT. OPS CHECK CARRIED OUT SERVICEABLE. NO FURTHER RECURRENCE. THE INLINE FILTERS ON THE ORIGINAL SELECTOR VALVE WERE INSPECTED WITH NO FINDINGS, FILTERS NOT COLLAPSED OR CONTAMINATED.