How to Recharge the A/C in a Dodge Ramby Lee Sallings
Over time, small amounts of refrigerant can leak out of the air conditioning system in your Dodge Ram truck. This, along with the occasional air-conditioning repair that is done, will require the system to be recharged. Recharging a completely empty system will require the system to be evacuated of any moisture. Use a vacuum pump to pull a vacuum on the system and remove the moisture. Simply topping off the system may not require this, but it is good to know how to do it anyway.
Install the A/C gauge set by locating the service ports located on the lines. Attach the blue hose of the set to the low-pressure side and the red hose of the set to the high-pressure side. The low-pressure fitting is located on the accumulator near the passenger side of the firewall, and the high-pressure fitting is located on the line connecting the condenser (located in front of the radiator) to the evaporator (located behind the firewall in the passenger compartment).
Attach the yellow service hose of the gauge set to the vacuum pump if you are going to pull a vacuum on the system to remove moisture. The system must be completely empty to do this to avoid damage to the pump. If you are simply topping the system off, skip this step and go to Step 3. Turn the pump on and open the service valves on the gauge set. Allow the vacuum pump to run for one hour to ensure all moisture has been removed from the system.
Close the service valves on the gauge set and disconnect the vacuum pump. Attach the can tap that came with your gauge set and attach a can of refrigerant to the tap. Turn the thumbscrew on the can tap all the way in and all of the way out to open the can. Open the blue, low-pressure side, service valve on the gauge set, and allow refrigerant into the system. Start the engine and set the air-conditioning controls to maximum A/C. When the first can is empty, close the service valve and attach another can. Continue this until the required amount of refrigerant has been added.
Turn off the engine and allow the pressures displayed on the gauge set to equalize. Remove the hoses from the service ports and replace any caps that were on the service ports.
Things You'll Need
- A/C gauge set
- Vacuum pump
Lee Sallings is a freelance writer from Fort Worth, Texas. Specializing in website content and design for the automobile enthusiast, he also has many years of experience in the auto repair industry. He has written Web content for eHow, and designed the DIY-Auto-Repair.com website. He began his writing career developing and teaching automotive technical training programs.