Modulating Pressure Test
- Remove vacuum line and holder from vacuum control unit (modulator). Place transmission in "D" position and drive vehicle on road or on dynamometer at 31 MPH. Apply full throttle and maintain speed at 31 MPH by lightly applying brakes.
- Read resulting pressure on gauge attached to modulating pressure port on transmission. Pressure should be as shown in MODULATING PRESSURE table.
- If necessary, adjust modulating pressure. Modulator pressure port is next to vacuum control unit at 4 o'clock position. Disconnect vacuum hose and remove rubber cap from vacuum control unit. Pull "T" handle out of locking slots to permit rotation. Turning "T" handle one rotation in vacuum control unit results in pressure change of about 6 psi (.422 kg/cm2 ). Adjust to correct value. See MODULATING PRESSURE table.
- After adjusting pressure, push "T" handle back into locking slots. Put rubber cap back on vacuum control unit. Connect vacuum hose, and check modulating pressure.
MODULATING PRESSURE
| Model | (1) psi (kPa) | ||
|---|---|---|---|
| C220 | 53.7 (370) | ||
| C280 | 56.6 (390) | ||
| E300D | 47.1 (325) | ||
| E320 | 60.9 (420) | ||
| S350D | 44.9 (310) | ||
| E420 | 55.1 (380) | ||
| S320 | 58.0 (400) | ||
| S420 | 55.1 (380) | ||
| S500 | 58.0 (400) | ||
| SL320 | 58.0 (400) | ||
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NOTE:
Modulating pressure must be measured and adjusted before performing working pressure and governor pressure tests.