Inquiry No. 5,719: Paul Magès inventories hydraulic leaks on the DS 19 (25 January 1962)

In this document

This document is the response from Paul Magès to "Inquiry No. 5,719", dated 25 January 1962, explicitly following up on his own "Note BEA43.027 of 9.12.61" p. 16. In it, he draws up a reasoned inventory of hydraulic leaks and seeps observed on the DS 19, specifying from the outset that he has "not been aware of any sudden leaks" that have caused cars to break down on the road since the start of the centrifugal regulator p. 16.

Category 1 — serious leaks (noticeable drop in reservoir level)

Magès deems these leaks dangerous because "users do not regularly check the level of their reservoir" p. 16. He cites:

• leaks at the clutch cylinder (seeps around 10,000 km, actual leaks around 20,000 km);
• leaks at the gearbox fork control cylinders, with the concrete case of a gearbox damaged at 23,000 km (vehicle from the Ministry of the Merchant Navy, shown to Mr. Guyetant);
• leaks at the end seals of the steering rack control piston, including on pre-production models with Teflon seals;
• leaks on the return of the suspension blocks, due to the destruction of the dust covers, "mainly at the front" p. 16-17.

Category 2 — minor or rarer leaks (p. 17)

Category 3 and final remark

A third category concerns leaks "originating from the attack of Armco pipes", reported in the USA but never seen by Magès himself p. 17. He concludes with a note of admitted ignorance: "I still know nothing regarding possible leaks on the pedal assembly of the current type" p. 17.

Numerous later red annotations punctuate the text, including one dated "6/10/69" and a mention "new JF35 seal and leak recovery" p. 17, indicating a review and operational monitoring several years after drafting.

Context

The DS 19, launched in 1955, popularized the hydropneumatic suspension designed by Paul Magès, a Citroën engineer. This system, as well as the steering, brakes, and gearbox control, relied on a common high-pressure hydraulic circuit, which made the slightest leak potentially critical for several components at once — a challenge well known to the brand at that time of industrial development.

The centrifugal regulator, the high-pressure pump, and the various seals (Teflon, then JF 35) mentioned here are part of this unified hydraulic architecture, then in constant improvement at the turn of the 1960s.

Archivist's perspective

This document illustrates the role of Magès not only as an inventor but as a manager of quality monitoring in actual service, listening to the network (users, taxis, overseas subsidiaries like Madagascar, incidents reported in the USA). His method — classification by severity, quantification in mileage, mention of specific cases — testifies to the rigor of an engineer concerned with the reliability perceived by the customer, beyond mere technical performance.

It is likely a piece of a continuous monitoring file, in direct connection with the Note BEA 43.027 from Paul Magès to Mr. Duclos — operational safety of the hydraulics (19 December 1961) which it explicitly extends. The late red annotations (including one dated 1969) suggest that this document was reused long after its drafting as a reference to track the evolution of the solutions provided, particularly regarding the JF 35 seal.