1989 420 SEL ABS Hydraulic Replacement

[Cigar Havana]

On a 1989 420SEL with 265,000 KM the ABS light comes on after rolling about 10 yards. This happens consistently. My mechanic tested the ABS system with one of those special test boxes and indicated the ABS hydraulic unit is not performing properly. We replaced the relays in the unit, but the light still comes on. So it seems the base unit has to be replaced.

I just bought a used unit, bosch part number 0 265 200 043. It is that rectangular box on the drivers' side fender, with all of the brake lines leading into it.

Is there anything special I need to do to install it? Do just undo all of the brake lines, open the plastic cover, pull the connector, remove the grounding strap, and put in the new unit, reconnect brake lines and electrics, and then bleed the entire brake system? (brake bleeding with a pressure unit, starting with right rear, left rear, right front, left front)