15-Hydraulique - On the Road

six-h kenteken 20212





rit15h 20817For a while, registration of the 15-H was rather uncertain since in August of 2010 the Dutch Road Vehicle Registration Authority (RDW) had announced they would no longer register imported vehicles without a valid registration document, issued in the country of origin. The Federation of Classic Vehicle Clubs protested successfully, claiming that many oldtimers imported from EU countries of which the original documents had been lost, were being restored at considerable cost as a contribution to preserve automotive heritage.


As of 1 January 2011, the rules were relaxed for historic vehicles of which the owner could prove that they had been legally imported from an EU member country. With my 15-H, I had a document from the Internal Revenue Dept, stating that the car had been imported from France as a “wreck” back in 1988. Together with a formal statement issued by the Conservatoire Citroën showing the numbers and the date the car had left the factory (8 June 1955), and a copy of the original homologation document issued by the French Ministry of Transport back in 1954, Registration now became a mere formality. Issuing the license documents took no more than a week.


six-h kenteken 20234The 15-H has been in a roadworthy condition for some time already -although I never seem to stop making improvements to enhance the car’s safety and/or reliability. There are many things to the car that still need finishing, like the interior and some chrome plating that needs to be done. With the registration, I can now move the car around a lot easier, for instance drop it off at an upholsterer for the interior to be finished.

The fact that not everything is ready yet, does not stop me from taking the car out on the roads to get to know its performance and road behaviour. Naturally, I was particularly interested in the combination of conventional (torsion bar) front and hydropneumatic rear suspension, this being the main feature of a 15-H.

six-h kenteken 20217My experience with the black 15-Six is that after a refit it takes a while before everything is running smoothly. This goes for things like the suspension, the brakes and the engine. The 15-H has brand new -original stock!- silent blocks in the front suspension. This makes the front of the car rather stiff compared to the black Six, which still has the original silent blocks, now some 58 years old. I am quite sure that it will take a few thousand km (or miles) of driving before this will improve. The same goes for the brakes. Brake linings are new and have to wear in a bit, allowing the centring of the shoes with the drums to become perfect. The heavier HY-Van front brake drums are proving effective already.  The engine runs beautifully -I have never heard or felt a Six engine that runs with as little vibration as this one, but the pistons are still in the process of running in and from experience I know that it will take some 5000 km for the engine to be at its very best. For that reason, I prefer to stick to a cruising speed of about 95 km/h (60 mph) for the moment.

The hydropneumatic rear suspension behaves exactly as it should. It makes you believe you are floating on air without noticing a lot of any unevenness of the pavement. In combination with thick (Dunlopillo foam back) carpeting and extra soft rear seat filling, I expect this to provide an excellent ride when everything is ready. Once the front suspension will have softened up a bit, the balance between front and rear is likely to become better as well.

Other details like the gearbox and the electrical systems are also important. A gearbox can only be truly tested on the road, in hot running condition. Since the gearbox of the 15-H was partly overhauled (taken apart and reassembled by myself), I was anxious to find out how it would work. I am pleased to find that it is reasonably silent and that the gears change quite well. Synchromeshes (on 2nd and 3rd) work surprisingly well -better than those of the black 15-Six.


rit15h 20794The 15-H runs on 12v -I decided to make this change right from the start. There are obvious advantages to running on the higher voltage, reducing the loss of tension through the cabling. Furthermore, 12v parts, appliances, lamp bulbs, etc are easier to come by. Downside is of course that (French) Tractions are supposed to run on 6v. So I committed a deliberate breach of originality. The black Six sill runs on 6v and I intend to keep it that way. This puts me right in the middle between those who wish to adhere strictly to originality and those who believe that some improvements do add to the practical usability of oldtimer cars.