so i do know that i have to filll the ac at the valve that is on the left side of the radiator.
now do i have to put the AC to the maximum cold while i charge it as it says in the can????
and is the R134a refrigerant synthetic the same as the other R-134a?
and how many of these cans does the AC of a 90 accord ex?????

 

If you have a 90 accord you have to change the system over from r-12 to r-134a. The only way you can tell if there is enough refrigerant in the a/c system it to get a presser gauge.

 

my system is already changed from r12 to r134.
my question was
is SYNTHETIC R134a the same as the cans that only say R134a?
and do i put the ac to the maximum while i fill the sytem(as it says in the can's directions)