Description
Original Bosch Vacuum Advance Unit 1 237 121 987 – NOS / New Old Stock
#1149
For sale is an original Bosch Vacuum Advance Unit 1 237 121 987 from old stock (NOS – New Old Stock).
This vacuum advance unit is an unused original spare part from earlier Bosch production.
Original Bosch vacuum advance units are particularly interesting for the professional rebuild and faithful restoration of classic Mercedes-Benz ignition distributors and classic cars.
The vacuum advance unit is part of the ignition timing adjustment and enables vacuum-dependent adjustment of the ignition timing. The applied vacuum actuates the adjustment mechanism in the ignition distributor.
A correctly functioning vacuum advance adjustment is important for maintaining the manufacturer’s specified ignition curve.
Product Details
- Manufacturer: Bosch
- Item: Vacuum Advance Unit / Vacuum Adjuster
- Bosch Part Number: 1 237 121 987 / 1237121987
- Bosch Short Number: 07123
- Mercedes-Benz Reference Number: A 000 158 36 18
- Condition: NOS – New Old Stock (unused stock)
- Application: Vacuum-Dependent Ignition Timing Adjustment
- Application: Classic Bosch ignition distributors
Vehicle Assignment
The Mercedes-Benz reference number A 000 158 36 18 is listed, among others, in the spare parts catalog of the Mercedes-Benz 450 SL (R107) with the M117.982 engine.
Since different ignition distributors and vacuum advance units were used within this vehicle series, the exact assignment must be verified using the originally installed part number and ignition distributor number.
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 faithful restoration of historic ignition systems, original Bosch spare parts from older stock are particularly interesting.
Important note on item condition:
Due to age and storage, sometimes for decades, both the original packaging, if available, and the item itself may show signs of storage and aging. These include, for example, dust, light scratches, discoloration, or superficial corrosion.
Please observe the product images and the information on the respective item condition.
Fitment and Application
Before purchasing, please compare the Bosch part number 1 237 121 987 or the Mercedes-Benz reference number A 000 158 36 18 with your existing component.
Vacuum advance units of different Bosch ignition distributors can vary in terms of their mounting, adjustment characteristics, and vacuum curve. An optically similar design is therefore not necessarily interchangeable.
If you have 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 rebuild.











