What Are Typical 134A Manifold Gauge Pressures?

by Amy Rodriguez
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A vehicle's air conditioning system is an important component in hot weather. The 134A refrigerant, and its resulting manifold pressure, provide a way to maintain the coolest air for the vehicle's occupants.


Run through a car's air conditioning system, 134A refrigerant acts as the cooling conductor for the air. Periodically, the refrigerant can become low, resulting in warmer air through the system and into the vehicle.


While recharging the system with refrigerant, the 134A manifold gauge pressure should be monitored so the proper amount of refrigerant is used. Two different pressure gauges can be used, either low or high. For a low pressure gauge, a reading of 25 pounds per square inch (psi)to 40 psi is optimum. On the other hand, a high pressure gauge should read between 225 psi and 250 psi.


If the refrigerant becomes low after a few months of circulation, there may be a leak in the system. AA1 Car recommends having the leak repaired before trying to recharge the system again.

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