Clément-Bayard factory, Levalois-Perret, late 80s:
Ah, Pierre, shall we use ‘ose clips on any of zee many joints of zis deux-cheveaux fuel line?
Bah non, John-Paul, zey cost two centimes each – do you zink, Monsieur Citroën, ‘e is made of money?
Bof, ah theenk it is time for luunch anyway. Where is zee vin rouge?
It occur to me – whilst ah eat mah baguette and drink mah vin rouge – zat maybe one of zeese unclipped joints may be zee weakest link in zis system as it can flex more zan zee rubber pipe we put in to abszob zee flex.
Bof, we shall let some crazy Eeenglish fool deal wizz zat in 30 years.
30 years later:
After checking the visible fuel line for potential leaks the only place left to check was on top of the fuel tank and the only way to check that is to unbolt and lower the fuel tank. As fully lowering the fuel tank is realistically a two person job I had to make do with lowering it about 10cm using a trolley jack. This didn’t give me much access but I could see what was going on and get in with one hand.
There is a metal pipe that comes up from the fuel tank onto which a short length of rubber hose is attached. The other end of the hose is attached to a PVC fuel line which then runs down to the front of the chassis. This is a pretty good system for joining the metal pipe to the main PVC fuel line as the rubber hose can absorb any flex in the system between the fuel tank (which is mounted on rubber bushes) and the chassis. However, without a clip on the joint it means that the joint becomes the weakest point.
Examining this I could see that the hose at this joint in the fuel line had indeed developed a small split right at the end, weakening the joint, so was a potential source of a leak. Being at a high point of the system it wasn’t going to be letting fuel out but would have been allowing some air in.
Ideally I would have liked to replace the length of rubber hose but, with limited access, the best I was able to do was put a hose clip on the joint to hold the split closed and reinforce the joint.
This isn’t a long term fix but does buy me some time until I can fully replace the fuel line. With hose clips at every joint this time…
Update: With the able assistance and extra resources of TomB engineering we fully dropped the tank and that short length of split hose was replaced as part of a larger piece of work.