Operation CHARM: Car repair manuals for everyone.

Vacuum System Check

Before connecting a vacuum pump to the A/C system, connect the pump to the low-pressure gage to determine the vacuum pump capability. If the vacuum pump is unable to reach at least 711.2-736.6 mm (28" to 29" Hg) vacuum, check the system for leaks. If no leaks are found, the vacuum pump may require repair.