Testing The Ad-4 Air Dryer - BENDIX AD-4 AIR DRYER Manual

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3. For AD-4 air dryer end covers with a dual terminal (See
Figure 6) heater connections, the power and insulated
return wires may be connected to either terminal. An
8-10 amp fuse should be installed in the power carrying
wire. Use 16 gauge wire for both power and return.
4. All electrical connections must be waterproofed.
5. Tie wrap or support all electrical wire leading to the
AD-4 ™ air dryer at 6 - 8 inch intervals. Note: Wires should
have sufficient slack and not be completely taught.
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TESTING THE AD-4
Before placing the vehicle in service, perform the following
tests:
1. Close all reservoir drain cocks.
2. Build up system pressure to governor cut-out and note
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that the AD-4 air dryer purges with an audible escape
of air.
3. "Fan" the service brakes to reduce system air pressure
to governor cut-in. Note that the system once again builds
to full pressure and is followed by a purge at the AD-4
air dryer exhaust.
4. It is recommended that the following items be tested for
leakage to assure that the AD-4
excessively.
(A) Total air system leakage (See Bendix publication
BW-5057 "Air Brake Handbook").
(B) Compressor unloader mechanism.
(C) Governor.
(D) Drain cock and safety valve in first (supply) reservoir.
(E) All air connections leading to and from the first
(supply) reservoir.
AIR DRYER
™ air dryer will not cycle
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