Could someone please tell me where the Vacuum Modulator for the auto transmission (E 300 D 124 chasis) is located and how to check it's condition and the vacuum pressure.

Thanks in advance.

 

left side f trans in ft...its color coated ...bllack . grenn .red etc ..just take rubber cap off of it ,,in shifts hard out softer....go 1 full turn at i time ..make notes how for you turns it ...chack to make sure that atf is not in the clear vac line if so mod vavle is bad ..pump it up and see if it holds vac..