Set-up and perform the Brake Air Differential Test, with no trailer or dolly (continued):
NOTE:
Immediately after that glad-hand in the Diff Kit is a brass nipple which has an orifice inside to
allow air flow into the Diff Kit at a specific rate. The size of the FMVSS-121 specified orifice is
0.0180 inches diameter (about diameter of a pin). Air must flow through this orifice before getting to
any sensors being used for this test.
3. Verify that a cable (attached earlier) is still connected to the “Sensor Port” on the right side of the
Tester. This cable and sensor is part of the Diff Kit.
4.
Attach the 50 CI reservoir
to the open glad-hand on the Diff Kit.
5. A sensor and cable assembly (PN 17200)
should still be connected
to the quick disconnect on
the 50 CI canister assembly. The sensor should still be connected to a port on the hub.
6. The
“Setup Hub Sensors”
view will now be shown. The sensor attached to the hub was
selected to be “Curbside” for the Air Leak and 121 Timing Tests. This sensor needs to be changed
from “Curbside” to “Rear”. Then click on “Continue” in the box below the list of Sensors.
The
Differential Test will now start and run.
7.
If the Test Passes,
another popup will be shown notifying you to “Disconnect the Differential Kit”.
But you don’t technically have to disconnect it at this time to successfully complete this test. This
popup just shows up at the end of a successful Differential Test.
8.
Now click on “Continue”
on the popup. You will be shown a “Certifier Report” with the results
of the tests that have been run: The Air Leak Test and 121 Timing Test results are in the “AIR
CONDITIONS” portion of the Report. The Differential Test results are shown in the “DIFFERENTIAL
TEST” portion.
9.
If the Test Fails,
hit “Retry” to run the Differential Test again. If it fails a 2
nd
time, call LITE-
CHECK for assistance.
10.
If the Test Passes,
remove the Diff Kit and save the data from the Certifier Report if desired.
Lite-Check CERTIFIER 1200 Operations Manual
14
This is the end of the SERVICE Brake Differential Test with no trailer or dolly.
