Exam 55: Heating and Air Conditioning Diagnosis and Service

During the recharging procedure: if the ____________________ hand valve is opened with the system operating, the refrigerant container could explode!

Temperature/pressure charts are not required when manifold gauges are used in A/C performance testing.

Upon reaching a 26 to 29 in. Hg vacuum reading, the vacuum pump should remain on and connected to the system for at least ____________________ minutes while evacuating an A/C system.

There is a specific recovery/recycle/recharge machine designed to service R-1234yf systems.

Unpleasant odors coming from the A/C system can be eliminated by ______.

Technician A uses the ohmmeter function of a DMM (digital multimeter)to test the resistor block for opens. Technician B tests the resistor block with a lab scope. Who is correct?

R-12 systems use ____________________based oils.

Bubbles in the sight glass of an R12 system indicate _____.

Technician A says air in the system can cause excessive pressure within the A/C system. Technician B says moisture can cause freeze-up at the expansion valve. Who is correct?

When installing an A/C system filter: if the filter does not have an orifice tube, it should be installed in the _____ line.

Some late model air-conditioning systems have a(n)____________________ capability that can be helpful when troubleshooting problems.

Technician A stores recycled refrigerant in emptied new refrigerant tanks. Technician B stores recycled refrigerant in UL-approved containers. Who is correct?

Explain how the Schrader valves are opened when the R134a manifold gauge hoses are connected to the A/C service fittings.

According to Section 609 of the Federal Clean Air Act, no one repairing or servicing a motor  vehicle's A/C system can do so unless that person is properly trained and certified.

How are manifold gauge service hoses colored?

Explain what may result if there is too little oil in an A/C system as well as if there is too much oil.

A loss of ____________________ ounces of R-134a refrigerant per year is acceptable.

Why must air be removed from the A/C system during servicing?

What methods are commonly used to locate refrigerant leaks?

In some states and provinces, a technician  must be certified by an EPA-approved program to buy refrigerant.