Bosch Vacuum Advance Unit 1 237 122 781 – NOS original part | Mercedes-Benz

Description

Original Bosch vacuum advance unit 1 237 122 781 – NOS / New Old Stock

For sale is an original Bosch vacuum advance unit 1 237 122 781 from old stock (NOS – New Old Stock).

This vacuum actuator is an unused original spare part from earlier Bosch production.

The vacuum advance unit is intended for specific classic Mercedes-Benz ignition systems. It is listed, among others, in connection with Mercedes-Benz V8 engines of the M116 and M117 series.

Original Bosch vacuum advance units are particularly interesting for the professional rebuild and authentic restoration of historical ignition systems and classic cars.

The vacuum advance unit is part of the ignition timing adjustment and enables a load-dependent adjustment of the ignition timing. The adjustment mechanism in the ignition distributor is actuated via the applied vacuum.

A correctly functioning vacuum advance is important for maintaining the manufacturer’s specified ignition map and contributes to smooth engine operation.

Product Details

• Manufacturer: Bosch
• Item: Vacuum advance unit / vacuum actuator
• Bosch part number: 1 237 122 781 / 1237122781
• Mercedes-Benz cross-reference number: A 000 158 59 18, A0001585918
• Condition: NOS – New Old Stock (unused stock)
• Use: Vacuum-dependent ignition timing adjustment
• Application: Classic Mercedes-Benz ignition systems

Vehicle Assignment

For the Mercedes-Benz cross-reference number A 000 158 59 18, there are application notes for the following vehicle, among others:

Mercedes-Benz 450 SL (R107)

• Engine: M117.985
• Displacement: 4,520 cm³
• Year: 1980
• Version: USA
• Assignment: depending on the engine number and the installed ignition distributor version

Important: Various vacuum advance units with different adjustment characteristics were used within the Mercedes-Benz V8 series. The vehicle assignment mentioned therefore does not represent a general installation approval.

Please check the complete Bosch part number or the Mercedes-Benz cross-reference number as well as the required vacuum curve before purchasing.

NOS – Original spare part from old stock

NOS stands for New Old Stock and refers to unused original spare parts from earlier production.

Original Bosch spare parts from older stock are particularly interesting for the authentic restoration of historical Mercedes-Benz ignition systems.

Important note on item condition:

Due to age and in some cases decades of storage, both the original packaging, if present, and the item itself may show signs of storage and aging. These include, for example, dust, light scratches, discoloration, or superficial traces of corrosion.

Please note the product images and the information on the respective item condition.

Fitment and Application

Please compare the Bosch part number 1 237 122 781 or the Mercedes-Benz cross-reference number A 000 158 59 18 with your existing component before purchasing.

Vacuum advance units of different Bosch ignition distributors can differ in terms of their mounting, adjustment characteristics, and vacuum curve. A visually similar version is therefore not necessarily interchangeable.

If you have any questions regarding compatibility or the item, we will be happy to assist you.

Radspieler Classic – Your specialist for classic Bosch spare parts, classic car technology, and professional ignition distributor rebuilds.