Vacuum Modulator Valve Adjustment

[Harshman]

What is the procedure for adjusting the modulator valve on a 1970 280S automatic? I'm experiencing flaring in the initial shift and was told that a modulator valve adjustment may correct the problem, but I am unable to find reference for the adjustment.

[Tom Hanson]

It's probably time to find an MB transmission mechanic with alot of grey in his hair. Or you could call my brother-in-law (sho has no hair) at 714 532-1871. He only does MB trans work at his shop. Just tell him Tom from Caliber told you to call. He's very familiar with these. By the way, I don't have much hair left either..

[wjaycox]

The adjustment is done as follows:
Attach a 100 psi gauge to the modulator pressure checkpoint . Remove the banjo bolt joining the vacuum line to the modulator. Using a 4 mm allen (late) or 5mm allen (early) wrench inserted into the the modulator pressure cell, rotate the allen bolt inside clockwise to increase pressure or conuter-clockwise to decrease pressure.
Run the car to 3000 rpm (65km/hr) with vacuum disconnected.Pressure should be about 54 psi on older models such as the 280s