Neil,

according to the "Tabellenbuch Personenwagen" from April 1991 the brake booster for 190E 2.6 and 500E both are tandem ones with 8"/9" diameter, OEM part numbers are ATE T52/4A/225-210 or Girling LSC 115. They should be identical while the 300TE has a 10" single membran brake booster.

The master cylinder is different, the 190E 2.6 has the same as a 300TE (15/16" and 3/4") but the 500E got a larger master cylinder with 1" / 3/4".

The overall pressure in the brake line is nearly the same for 300TE and 190E 2.6 - but the 500E produces more pressure for the same weight of your foot.

bis denn,
Christian

1989 300TE