What pressure range should the low side go to when the A C is turned on?
30 PSI
An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side.
What to do when pressure gauges are wrong?
Connect the high side coupler to the high side port and connect the low side coupler to the low side port. Start the vehicle. Turn on the A/C system, and let it run until gauge readings stabilize. If the pressure shown on the gauges differ from the manufacturer’s specs, determine the problem and make necessary repairs.
What’s the difference between high and low pressure gauges?
Cross contamination of refrigerants can cause damage to A/C system, service tools and equipment. The right (red) side of the manifold is the high side and the red gauge is the high pressure gauge. The left (blue) side of the manifold is the low side and the blue gauge is the vacuum/pressure gauge.
How do you close the valves on a manifold gauge?
Close all valves on the manual service couplers and manifold gauge set. Connect the high side coupler to the high side port and connect the low side coupler to the low side port.
What should the AC manifold gauge readings mean?
When the low side is high, and the high side is low, the compressor is not functioning properly. Similarly, you may ask, what should AC manifold gauges read? The gauges readings will depend on the ambient temperature. With the A/C turned OFF – On a cold day the pressure will be low, on a hot day the pressure will be high.
What should the low side pressure gauge read?
“With the compressor off and the low-side pressure gauge installed onto the suction service valve, front seat the suction service valve and turn on the compressor. The low-side gauge should read at least a 20-inch vacuum within a minute or so.
What does low side gauge on air conditioner mean?
Then the low side gauge will climb back up to 45 psi as the high and low side equalize. At this point, he compressor will kick back on and the cycle will repeat itself. This is called short cycling. This rapid cycling of the compressor is a good indication that the system is low of refrigerant.
What causes a low reading on a vacuum gauge?
Common causes of steady low reading are blowby due to worn piston rings or possibly late ignition or valve timing. An extremely low reading could also indicate an air leak at the intake manifold or throttle body. A regular swing between high and low readings often means a blown head gasket between two, side-by-side cylinders.
What to look for when expansion valve is stuck?
A gauge reading of less than 200 psi on the high side will be seen when this happens. When stuck closed, a higher than normal high side reading will be seen. Typically, this will be over 400 psi and climb until the high-pressure switch shuts down the system. Very low or very high readings on the high-side gauge indicate a faulty expansion valve.