Motorola APX 5000 Service Manual page 281

Disassembly/Reassembly Procedures: Ensuring Radio Submergibility
8.10.8 Pressure Test (using NTN4265_)
Pressure testing the radio is necessary only if the radio has failed the vacuum test. Do not perform
the pressure test until the vacuum test has been completed. Pressure testing involves creating a
positive pressure 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
and Parts Lists" on page
If the radio is still set up from vacuum test, skip steps 1 through 4.
To conduct the pressure test:
1. Ensure that an seal is attached to the Vacuum Adapter.
2. Attach the Vacuum Adapter onto the radio in the same manner as a radio battery. Ensure
both the latches are clicked into place.
NOTE: Vacuum Port door must be opened and held out of the way prior to assembly of the
3. Attach one end of the hose to the Pressure Pump. Attach the other side of the hose to the
Vacuum Adapter.
4. Operate the pump until the gauge reads approximately 1 psig.
5. Maintain the pressure around 1 psig and submerge the radio into a water-filled container.
6. Watch for any continuous series of bubbles. A steady stream of bubbles indicates a sign of
leakage.
NOTE: Some accumulation of air may be entrapped in the main housing which may cause a false
diagnosis of a leak. Ensure there is a steady stream of bubbles before concluding there is a
leak.
7. Note all of the seal areas that show signs of leakage. Rotate the radio to view all sides to
pinpoint the problem(s) to one (or more) of the following areas:
• Seal Interfaces
• Speaker Assembly
• Battery Connector Seal
2:10-1.
Vacuum Adaptor.
Pressure must remain between 0.5 psig and 1.5 psig.
Pressure lower then 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.
Sec 2: 8-43
"Chapter 10: Exploded Views