by Kent Bergsma
The old diesel vacuum pumps that were installed on cars up through 1979 use a rubber diaphragm that is prone to failure after years of use. Also, if you are getting an old Benz diesel that has not run in years you might want to look inside the pump before you start driving the car. Kits are available to overhaul these old pumps at Mercedessource.com with complete instructions. This applies to the 220D, 240D, 300D, 300CD and 300TD up through 1979.