Bosch Vacuum Advance Unit 1 237 121 903 – NOS Original Part | Mercedes-Benz 280

Description

Original Bosch Vacuum Advance Unit 1 237 121 903 – NOS / New Old Stock

#1152

For sale is an original Bosch vacuum advance unit 1 237 121 903 from old stock (NOS – New Old Stock).

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

The vacuum advance unit is intended, among others, for the Bosch ignition distributor 0 231 309 001, which is used in various classic Mercedes-Benz vehicles with the M110 six-cylinder engine and carburetor.

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

The vacuum advance unit is part of the ignition timing adjustment and enables a vacuum-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 ignition curve specified by the manufacturer.

Product Details

• Manufacturer: Bosch
• Item: Vacuum advance unit / vacuum advance regulator
• Bosch part number: 1 237 121 903 / 1237121903
• Mercedes-Benz cross-reference number: A 000 158 25 18
• Matching Bosch ignition distributor: 0 231 309 001
• Mercedes-Benz number of the ignition distributor: A 001 158 73 01
• Condition: NOS – New Old Stock (unused warehouse stock)
• Application: Vacuum-dependent ignition timing adjustment
• Field of use: Classic Mercedes-Benz M110 carburetor engines

Matching Vehicles

Mercedes-Benz 280 / 280 C (W114)

• Engine: M110.921
• Displacement: 2,746 cc, 6 cylinders
• Power: 160 hp (118 kW)
• Years of construction: approx. 1972–1977

Mercedes-Benz 280 S (W116)

• Engines: M110.922 / M110.932
• Displacement: 2,746 cc, 6 cylinders
• Power: 142–160 hp depending on version
• Years of construction: approx. 1972–1980

Mercedes-Benz 280 (W123)

• Engine: M110.923
• Displacement: 2,746 cc, 6 cylinders
• Power: 156 hp (115 kW)
• Years of construction: approx. 1976–1981

Mercedes-Benz 280 C (C123)

• Engine: M110.923
• Displacement: 2,746 cc, 6 cylinders
• Power: 156 hp (115 kW)
• Years of construction: approx. 1977–1980

Important: The specified years of construction refer to the respective vehicle versions. The vacuum advance unit 1 237 121 903 was not used throughout the entire production period of all mentioned models. For some versions, use is documented until October 1977.

Therefore, please check the number of the installed Bosch ignition distributor and the part number of the existing vacuum advance unit 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.

Especially for the authentic restoration of historical ignition systems, original Bosch spare parts from older stock are particularly interesting.

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 signs of corrosion.

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

Fitment and Application

Before purchasing, please compare the Bosch part number 1 237 121 903 or the Mercedes-Benz cross-reference number A 000 158 25 18 with your existing component.

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.