Product Manual

PART 8: AIR BRAKE TESTING

Complete the pretesting checklist prior to all testing procedures.

8.1 TESTING SETUP

1. Push the Power Source Switch to the OFF position.

2. Set both Emergency and Service Side Air Ball Valves to the CLOSED position.

3. Attach gladhand hoses from the MUTT

directly to your trailer’s air system, securing

the red hose to the Emergency Side and the blue hose to the Service Side.

4. Connect your shop air to the Shop Air Inlet on the left hand side of the tester.

5. Listen for any air leaks where the shop air connects to the tester, to avoid

erroneous results.

Set Emergency and Service Valves to CLOSED

Push Power Source Switch to OFF

Attach Gladhand Hoses

DANGER

CHOCK TRAILER WHEELS

WARNING!!! DO NOT CONNECT SHOP AIR UNTIL COMPLETING

THE TESTING SETUP PROCEDURE STEPS 1-5. FAILURE TO

FULLY UNDERSTAND THESE WARNINGS CAN RESULT IN MINOR

TO SERIOUS INJURY AND POSSIBLY DEATH.

Connect the Shop Air to the Shop Air Inlet

NOTE: In some cases, a crossed circuit may be a normal function of advanced

diagnostic testing, such as with certain ABS systems.

SHORT/OVERLOADED CIRCUIT

Short circuits or overloads can occur when a positive, hot wire touches ground.

They can also occur due to faulty lights or connectors.

1. If a short or overloaded circuit is suspected, the MUTT

will instantly stop

powering the circuit.

2. The Overload Warning Indicator will then ﬂ ash, along with the selected circuit’s

LED. The ammeter needle will also max out and return to 0.

3. The MUTT

will now automatically enter Pulsar Mode. During Pulsar Mode, the

MUTT

will attempt to reapply power to the faulty circuit every 3 seconds for an

indeﬁ nite period of time. After power is applied, if a short is still present, steps 1-3

will automatically repeat.

Example: The MUTT

detects a short in the Clearance Light Circuit. The Clearance

LED and Overload Warning Indicator will ﬂ ash and a warning beep will sound. The

MUTT

will now enter Pulsar Mode.

NOTE: Pulsar Mode can be a useful troubleshooting tool for ﬁ nding dead and

intermittent shorts.

Example: Short Circuit in the Clearance Light