If your modulator is working ok, but leaking transmission fluid, you may only need to replace the inexpensive oring ( o ring ). You do have to be careful when removing the modulator from the transmission. For instructions (available separately) see related products below. For testing modulator pressure Kent has developed a DIY testing kit (see below).
Product Details
Related Products:
123 107 126 201 124 722.3x and 722.4x Transmission Modulator Valve Installation Inst PDF DOWNLOAD
Illustrated 6 page step-by-step instructions for proper removal and installation of the modulator upgrade for the years and models noted here. Includes how-to specific details for using the new adjustment cap on the upgraded OEM modulators now available. These are installation instructions only.
61x Diesel Automatic Transmission Modulator Pressure Test Kit
Applicable to 114 115 116 123 and 126 Chassis, years and models listed above. Troubleshooting an annoying shift problem must first start with the vacuum modulator.
722.3x Turbo Diesel Transmission Vacuum Modulator UPGRADE Green - Instructions Available Separately
This is the new Mercedes O.E.M. replacement for the GREEN transmission vacuum modulator found on most of the models listed above. This unit has been upgraded from the original for better shifting performance (you will note it looks quite different).
123 126 124 Chassis with 722.4x Transmission - Upgraded BLACK Modulator Valve
If you are experiencing very hard or less than perfect shifts, a failed transmission modulator could be the problem. New Genuine Mercedes part. This unit is an upgrade over the original. It has a better thrust pin design which is less prone to cause pressure variations in cold weather.