Motorola APX 4000, Basic Service Manual

Page: 475 / 526

Disassembly/Reassembly Procedures : Ensuring Radio Submergibility 8-41
8.7.8 Pressure Test (using NTN4265_)
Pressure testing the radio is necessary only if the radio has failed the vacuum test. Do not perform
the test until the vacuum test has been completed. Pressure test involves creating sealed condition
inside the radio, submerging the radio in water, and observing the radio for a stream of bubbles
(leak). Since all areas of the radio are being checked, observe the entire unit carefully for the
possibility of multiple leaks before completing this test.
NOTES: When Radio is placed under the water there will be some air trapped which will be released.
This is not a failure.
Refer to the exploded view diagrams and parts lists found in “Chapter 10: Exploded Views
and Parts Lists” .
To conduct the pressure test:
1. Observe is there is any torn on the Main O-ring and battery contact seal.
2. Ensure that the front kit and back kits are assembled properly.
3. Attach the pressure test fixture onto the vacuum port of the radio as shown in
Figure 8-56 .
4. Attach one end of the hose to the pressure pump. Attach the other side of the hose to the
pressure test fixture (P/N: TL000062A01).
5. Operate the pump until the gauge reads approximately 1 psig.
Figure 8-56. Attaching Pressure Test Fixture
6. Maintain the pressure around 1 psig and submerge the radio in a water-filled container.
Pressure must remain between 0.5 psig and 1.5 psig.
Pressure lower than 0.5 psig may allow water into the radio,
which will damage the radio.
Ensure that the pressure NEVER exceeds 1.5 psig. The radio
has pressure sensitive components that can be damaged if
the pressure exceeds this limit.
!
C a u t i o n
!
C a u t i o n