I think on old AC units They had a different valve than the shrader. It might be called a king? Anyway, I can't get my gauge to read the pressure. The needles don't move at all. How can I measure, refill this type of HVAC?
Unless you are EPA certified, you have no business checking the refrigerant in old AC units. If you get caught, you could face a hefty fine.
no offense,but i'm a little concerned that you have gauges and the knowhow to check freon,but dont know about different types of service / access valves.apply any advice at your own risk......anyway,,if you remove the large cap that covers the stem of the service valve you need to [ with gauges already connected] turn the stem clockwise to open it so your gauge can read the pressure,[ they make a special service valve wrench for this purpose,an adjustable wrench usually will work,but be careful not to strip the square end of the stem if its old and doesnt want to turn],,only turn the stem one or two times around,,DO NOT keep turning it clockwise until it stops or you will close the valve off....when finished checking with gauges,be sure to turn stem counterclockwise until it stops turning,,then you can safely remove gauges..if you remove gauges without turning stem counterclockwise,the the freon will blow out of the valve when gauges are removed,,not a pleasant experience,, be sure to where gloves and goggles,esp if you arent used to doing this......dan
