What kind of freon does a 1990 model gmc truck take?

The type of freon used in a vehicle is dependent on the year of manufacture and model. 1990 model GMC trucks use R-12 refrigerant, which is also known as dichlorodifluoromethane. This refrigerant was common in vehicles at that time but has since been phased out due to its negative impact on the environment and depleting ozone layers. Some older vehicles still in operation may still be using R-12, but it is important to check the specific requirements for your vehicle's air conditioning system to determine the appropriate refrigerant type. It's recommended to consult with a professional automotive technician or refer to the vehicle's owner manual for accurate information on the type of refrigerant required.