ATD Tools ATD-3692 User Manual

MANIFOLD OPERATING INSTRUCTIONS

ATD-3692

R134A ALUMINIUM MANIFOLD GAUGE
SET

WARNING: Always wear safety goggles when working with

refrigerants. Cont act with refrigerant can cause eye injury.
Disconnect hoses with extreme caution! Pressurized
refrigerant may be present in hoses. Always point hoses away
from you and anyone nearby.

Your manifold is designed so that all three lower fittings are connected to each other by
internal passages. Separate passages from the low and high side fittings to their
respective gauges give you pressure and vacuum readings whether the handwheels are
open or closed. For your convenience and safety, handwheels and gauges are
color-coded with the blue compound gauge on the left or low side, and the red pressure
gauge on the high or right side.

Diagnosing System Operation

1. Connect the blue low side hose to the A/C system’s low side service port. Connect the
red high side hose to the A/C system’s high side service port.

2. With the manifold handwheels closed, read the pressure on the gauge face.

3. Use the temperature/pressure chart in the back of this manual to find the
corresponding temperature for the refrigerant in the system.

4. Compare these pressure and temperatures to the A/C system manufacturer’s
specifications for proper operation.

5. If the system is within the correct operating guidelines, disconnect the manifold hoses
from the system. If repairs are necessary, follow the steps for recovering, evacuating
and recharging the system.

MANIFOLD OPERATING INSTRUCTIONS

Recovering Refrigerant

Note: According to federal law, refrigerant should not be exhausted to the atmosphere.

1. Be sure the blue low side hose is connected to the A/C system’s low side service port
and that the red high side hose is connected to the A/C system’s high side service
port.

Note: Typically, the yellow center hose is connected to the inlet of the recovery unit.

2. Follow the instructions provided with the recovery unit for proper recovery of
refrigerant from the A/C system.

Evacuating and Charging a Refrigerant System

1. Connect the blue low side hose to the A/C system’s low side service port. Connect the
red high side hose to the A/C system’s high side service port.

2. Check the manifold gauge pressure reading to be sure the A/C system has been
recovered properly. If it is not, follow steps under “Recovering Refrigerant”. If it is,
connect the center yellow charging hose to a vacuum pump.

3. Open the high and low side handwheels and start the vacuum pump.

4. After evacuating the system accordi ng to th e manufactur er’s specifications, close bot h
the high and low side handwheels and turn off th e vacuum pu mp .

5. Disconnect the yellow hose from the vacuum pump and connect it to the refrigerant
supply.

6. Slightly open the refrigerant supply valve. Purge air from the yellow charging hose at
the manifold, then close the supply valve.

7. You can now charge the A/C system according to the manufacturer’s specifications.

z If the system specifications call for charging on the high side, close the manifold’s

blue low side handwheel, open the refrigerant supply valve and open the manifold’s
red high side handwheel. After dispensing the proper amount of refrigerant, close the
manifold’s red high side handwheel a nd clo s e t h e refrigerant supply valve.

z

If the system specifications call for charging on the low side, close the manifold’s red
high side handwheel, open the refrigerant supply valve and open the manifold’s blue
low side handwheel. After dispensing the proper amount of refrigerant, close the
manifold’s blue low side handwheel and close the refrigerant supply valve.

8. When you have charged the system, close both manifold handwheels. Let the
compressor run and check the manifold’s gauge pressure readings to be sure the
system is operating properly. If it is not, adjust the system as necessary. To disconnect
the manifold when the system is operating correctly, first close the high side coupler
valve. Open the low side coupler valve. Then disconnect the red high side hose from
the A/C system.

9. Restart the A/C system, then open both manifold handwheels. Refrigerant from both
hoses will be drawn quickly into the A/C system through the blue low side hose.

10. When both gauges show the lowest operating pressure recommended by the
manufacturer, close the low side valve and turn off the A/C system.

11. Close the low side coupler valve and disconnect the low side hose from the A/C