Standardisation note no. 128: designation of liquids VF 10 A and VF 10 B

In this document

This is an internal standardisation note (no. 128) addressed by Mr Foucher to Messrs Magès and Prud'homme, within the Société Anonyme André Citroën p. 131.

Subject of the note

The note establishes an official designation for two distinct liquids used on vehicles:

• The original Lockheed brake fluid is now assigned the symbol VF 10 A p. 131.
• The Citroën-manufactured suspension fluid is assigned the symbol VF 10 B p. 131.

Visual distinction

To avoid any confusion between the two liquids, the VF 10 B is coloured orange-red, using a dye called "ORGANOL BS" p. 131.

Recommendation

The note indicates that "it would be interesting to use the fluid prepared in-house for suspension as needs arise" p. 131. It also specifies that the Laboratory, under the responsibility of Mr Valette, has the necessary quantities available p. 131.

The typewritten date "1-12-" is completed by the handwritten annotation "55", which places the note on 1 December 1955, consistent with the provided dating.

Context

This note is part of the context of the development of the hydropneumatic suspension of the Citroën DS, presented in 1955. The suspension fluid, distinct from conventional brake fluid, played a central role in this revolutionary system combining suspension and braking on the same hydraulic circuit.

The distinction between a liquid of British origin (Lockheed, manufacturer of automotive hydraulic components) and a liquid manufactured by Citroën itself illustrates the company's desire to control its own production chain, in a context where the reliability of the fluid was crucial for the safety and proper functioning of the DS's complex hydraulic system.

Archivist's perspective

This document, brief and purely administrative in nature, nevertheless bears witness to an important stage of industrial standardisation at the time when the hydropneumatic suspension entered mass production. It seems to reflect the concern for technical rigour that characterises the work of Magès and his collaborators: clearly distinguishing, by code and colour, two fluids with different functions but circulating in similar systems.

The red underlinings visible on the original ("liquide", "LOCKHEED", "VF 10 B", "rouge-orangé") suggest a careful review, probably intended to verify or disseminate these new designations to the teams concerned.

This document is part of the same collection as the Folder "Theoretical study – hydropneumatic suspension 1943/44", which traces the earlier origins of the system, and thus completes the chronology of the device's development up to its industrial standardisation phase in 1955.