Replace the cap on the A/C Schrader valve with a new metal valve cap that includes a rubber O-ring inside. Brush the cap and valve with soapy water and check for leaks, which would be indicated by bubbles.
A quality valve cap should keep a valve from leaking even if the valve itself is faulty. The valve cap can be used as a temporary fix until you have a technician take a look at the system or as part of a two-part repair to a leaky valve.
Attach the valve core removal tool to the uncapped Schrader valve to remove the valve core, then replace it with a new one. An air conditioning-specific core tool screws onto the valve, allowing you to remove the core and retain the coolant and pressure in the A/C system.
Remove the existing valve core by turning it counterclockwise with the core removal tool. As you pull the old core from the valve, close the valve on the core tool to conserve the coolant.
Install a new valve core while the core removal tool is still attached to the valve. Place the new core into the barrel of the tool and screw it into position, using the valve on the core tool to allow the new core to pass through the tool.
Valve cores are relatively delicate so only use enough pressure to snug the core tight in position.
Remove the valve core tool and check the cap-less valve for leaks. A new core should eliminate any leaks.
Replace the new valve cap to give the Shrader valve double leak protection.
Things You Will Need
- Soapy water
- New metal valve cap
- Shrader valve replacement core
- Valve core removal tool for air conditioning use
- Practice using the core removal tool on a bicycle or spare car tire if you're not familiar with valve core removal and replacement.