BENDIX SD-08-2418 manual Heater and Thermostat Connector

(Recommended intervals for trucks equipped with non- Bendix compressors are 6 months (50,000 miles), one year (100,000 miles) and two years (200,000 miles), respectively.)

2.Visually check for physical damage, such as chafed or broken air and electrical lines, and broken or missing parts.

3.Check the AD-IS®air dryer and purge reservoir bolts for tightness. See Figure 1. Re-torque the three air dryer bolts to 360–420 in-lbs and the four purge reservoir bolts to 300–360 in-lbs.

4.Perform the Operation & Leakage Tests listed in this publication.

!WARNING

This air dryer is intended to remove moisture and other contaminants normally found in the air brake system. Do not inject alcohol, anti-freeze, or other de-icing substances into—or upstream of—the air dryer and reservoir system. Alcohol is removed by the dryer, but reduces the effectiveness of the device to dry air. Use of these or other substances can damage the air dryer and may void the warranty.

OPERATION & LEAKAGE TESTS (REFER TO THE TROUBLESHOOTING CHART IN THIS MANUAL)

For additional information see video BW2237 — available through the Bendix Marketing Center on www.bendix.com.

1.Check all lines and fittings leading to and from the air dryer and reservoir system for leakage and integrity. Repair any leaks found.

2.Build up system pressure to governor cut-out and note that the Bendix® AD-IS®air dryer purges with an audible escape of air. Watch the system pressure and note the pressure fall-off for a ten minute period. If pressure drop exceeds—a) for a single vehicle: 1 psi/minute from either service reservoir; or b) for tractor trailer: 3 psi/minute from either service reservoir—inspect the vehicle air systems for leak sources and repair them. Refer to the Symptoms 1 and 4 in the Troubleshooting Chart.

3.CAUTION: Be sure to wear safety glasses in case of a purge blast. Check for excessive leakage around the purge valve with the compressor in the charge mode (compressing air). Apply a soap solution to the purge valve exhaust port and observe that leakage does not exceed a 1" bubble in one second. If any leakage exceeds the maximum specified, refer to Symptom 4 in the Troubleshooting Chart.

HEATER & THERMOSTAT

CONNECTOR

FIGURE 4 - HEATER AND THERMOSTAT CONNECTOR

4.Build up system pressure to governor cut-out and note that the AD-IS air dryer purges with an audible burst of air, followed immediately by approximately 30 seconds of air flowing out of the purge valve. "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. If the system does not follow this pattern, refer to Symptoms 5 and 6 in the Troubleshooting Chart .

5.Check the operation of the end cover heater and thermostat assembly during cold weather operation as follows:

A.Electric Power to the Dryer (Refer to Figure 4.)

With the ignition or engine kill switch in the RUN position, check for voltage to the heater and thermostat assembly using a voltmeter or test light. Unplug the electrical connector at the air dryer and reservoir system and place the test leads on each of the connections of the female connector on the vehicle power lead. If there is no voltage, look for a blown fuse, broken wires, or corrosion in the vehicle wiring harness. Check to see if a good ground path exists.

B.Thermostat and Heater Operation

Note: These tests are not possible except in cold weather operation.

Turn off the ignition switch and cool the thermostat and heater assembly to below 40° F. Using an ohmmeter, check the resistance between the electrical pins in the air dryer and reservoir system connector half. The resistance should be 1.5 to 3.0 ohms for the 12 volt heater assembly, and 6.0 to 9.0 ohms for the 24 volt heater assembly.

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