Date: Sat, 30 Jul 2005 18:15:37 GMT From: "James Sweet" <jamessweetnospamail.com> Subject: Re: 1992 saab 900s conv 2.1 ac problem
"David Taylor" <djtaylornospamoot.com> wrote in message news:MPG.1d55664c35855030989cfdnospam.cable.ntlworld.com... > > I think it might have been a pump until it is refilled. But once in awhile > > Thing is, there's no such thing as a "top-up" as the only way of topping > up would require knowledge of the quantity of what's in there in the > first place! > > David. If you connect a guage set to the low and high sides and then measure the temperature of ambient air outside and return air in the car and the suction line out of the evaporator you can determine the superheat which is a fairly good indication of refrigerant quantity. In practice many people just measure the low side pressure and the air temperature and guestimate though.