When the airtightness test does not provide the desired result: Primary causes of leakage in gas sampling pumps are looseness of the inlet nut, porosity of the inlet rubber, impure or insufficient sealing grease, etc. Please perform the necessary maintenance according to the procedures described in the sampling pump instructions manual. If the pump still leaks after performing the maintenance procedures according to the manual, immediately discontinue use, and contact your authorized Respo representative.