Nissan Repair: air con micra 07, presure valve, vacuum pump

Question
can i replace the gas myself with the halfords gas replacer if so where is the low presure valve

Answer
Anthony,
Yes, you can top off the gas yourself if there is ome in the system.  Otherwise it will have to be evacuated with a vacuum pump first.  Check the system pressures first to make sure there is some pressure in the system.  The low pressure side valve is by the receiver dryer.