Tools Required

1. Inspect the modulator components for the following conditions:

•	A damaged modulator valve (1)

•	A damaged modulator assembly (3)

•	A damaged modulator O-ring seal (4)

•	A damaged modulator retainer (2)

2. Install J 23738-A , or equivalent, onto the vacuum pipe nipple of the modulator assembly.
3. Apply 15 kPa of vacuum to the modulator assembly (32) under the following criteria:

•	Hold the vacuum for 30 seconds

•	Confirm that the plunger retracts into the modulator assembly

4. Remove J 23738-A , or equivalent, from the modulator assembly.



5. Use a modulator assembly that is known to be good.
6. Install J 36619 between the good modulator and the modulator to be checked.
7. Push the modulators towards each other.
8. Note the indicator on J 36619 .

•	If the indicator line (2) is visible, the modulator is OK

•	If the indicator line moves out of view, replace the modulator