TB-9-2510-251-13

TECHNICAL BULLETIN

OPERATOR AND FIELD MAINTENANCE; INSTALLATION MANUAL (INCLUDING REPAIR PARTS LIST); FOR ADD-ON-ARMOR (AoA) AIR CONDITIONING

AUGUST 2007

TB-9-2510-251-13 - Page 299 of 624

4-23

TB 9-2510-251-13

4-14

Air Conditioning System Servicing (Cont’d)

a. Discharge Air Conditioning System (Cont’d)

1)

Tighten all connections and attach a

vacuum pump to the center hose of the gauge set.

2)

Start the vacuum pump and fully open both hand valves on the manifold.

Run pump for five

minutes.

The system should reach a 30.0' Hg vacuum pressure within 90 seconds.

3)

Close both hand valves and shut off vacuum pump.

4)

Observe gauge readings for five minutes.

If gauge needles move up, the system is not

sealed.

Check for loose connections or broken O-rings.

Repeat Steps 1 through 4.

5)

Run the vacuum pump for a minimum of one hour to remove all moisture from system.

6)

Remove vacuum pump.

b. Purge Air Conditioning System

1)

Tighten all connections and attach a cylinder of dry nitrogen to the center hose of the

gauge set.

2)

Open nitrogen cylinder valve and allow to flow through system until all moisture is forced

out.

3)

Close nitrogen cylinder valve.

4)

Tighten all connections and attach a vacuum pump to the center hose of the gauge set.

5)

Start the vacuum pump and fully open both hand valves on the manifold.

Run pump for five

minutes.

6)

Close both hand valves and shut off pump.

7)

Observe gauge readings for five minutes.

If gauge needles move up, the system is not

sealed.

Repeat Steps 4 through 7.

8)

Run the vacuum pump at a 29.0” Hg vacuum for two hours.