B.E.A. Meeting no. 584 of 7 January 1958: Paul Magès' work schedule

In this document

These handwritten minutes cover a long technical planning session held on 7 January 1958 in Mr. Cadiou's office, in two parts (8:30 am and 9:45 am), in the presence of Paul Magès and several collaborators (Sabrazat, Lefebvre, Bocquet, Fujétaut, Coulombel, Louis, Richard). The document lists point by point, numbered 1 to 43, the technical problems currently affecting four major assemblies.

Clutch and gearbox

The most discussed point is the engine stalling when braking, attributed to excessive friction in the clutch: measurements revealed up to 3.85 kg·m of hysteresis against a target of 1 kg p. 266. Mr. Cadiou requests the creation of a list of points to be addressed, to be presented "in 15 days" p. 266. Other subjects are covered: clutch cylinder leakage entrusted to Fujétaut, clutch corrector, fast idle seal, seized piston, and the gear control cylinder in a "2-piece" solution that Mr. Cadiou wants to see "released" quickly p. 266.

H.P. pump and cut-out valve

Topics addressed include the sealing of cylinder head gaskets—Magès proposing an "expansion forge" around each gasket p. 267—, the noise of the H.P. pump ("we are expecting a scandalous noise"), and several improvements to the cut-out valve, including a steel solution that Magès supports because it is "smaller, lighter, more economical" p. 267.

Hydraulic steering

The second part of the session (9:45 am) deals with steering leaks: Krylène/rilsan rotating seal, "jacobtet" central seal, chrome washers that "scratch the cylinders" p. 268-269. Mr. Cadiou explicitly asks Magès to "assemble a steering system without a central seal" and mentions a special accumulator for the gear control p. 268. Mr. Louis points out the rapid wear of the central seal in hot countries p. 268.

Brakes

Finally, the leak at the brake pedal assembly (solution: external pedal assembly), the brake distributor, and a pipe rupture between the pump and cut-out valve are mentioned, for which Magès recommends a 6.35 non-brazed pipe p. 269.

Context

This meeting takes place during the period when Citroën was developing and perfecting the DS, launched in 1955, whose hydropneumatic suspension, power steering, and hydraulic braking constitute the major innovations designed by Paul Magès. The development difficulties mentioned here (leaks, noises, seal wear) are typical of the industrial beginnings of high-pressure hydraulic technology, which was then unprecedented in mass-produced automobiles.

Archivist's perspective

This document offers a precious snapshot of Paul Magès' daily engineering work, far from diagrams and patents: he appears here as a practitioner consulted directly on choices of materials (rilsan, teflon, steel) and technical solutions, arbitrating between reliability and cost. The tone of Mr. Cadiou, who presses several times for solutions to be "released" quickly p. 266, 268, shows the industrial pressure weighing on the B.E.A.

It seems that this piece belongs to the same collection as the Summary of folder 41-59, dedicated to the hydropneumatic suspension and its developments on the DS, which confirms its documentary coherence.