Modulating Pressure Test

Accelerate vehicle on the road or on a dynamometer to 53 MPH. Run engine at full throttle, and keep speed at 30 MPH by lightly applying service brakes. Read resulting pressure on gauge attached to modulating pressure take-off point on transmission. Pressure should check as shown in Modulating & Working Pressure chart; adjust as necessary.

Fig 1: Bottom View of Transmission Case Showing Location of Leaf Spring

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

NOTE: On models with diesel engines it may be necessary to adjust vacuum supply to modulator to obtain correct vacuum. If adjustment is needed, see appropriate SERVICING article in AUTOMATIC TRANSMISSIONS.