2CV fuel line ‘fixing’

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.

Supporting a 2CV fuel tank with a jack

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.

2CV fuel tank connections to the fuel line

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.

2CV fuel tank connections to the fuel line with hose clip

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.

Fuel line additions

After replacing the fuel hose last year I took another look at the fuel system. As Judith doesn’t get used regularly the fuel drains out of the elevated section to the pump when she’s sat for a while. As the fuel pump is mechanically driven from the engine and it’s designed to move liquid rather than air this means that the starter motor has to run for longer than is ideal to get things going. To overcome this I’ve got a manual fuel primer pump and a clear fuel filter to check the flow.

As always when working with the fuel system, disconnect the battery before starting.

I opted to fit the primer pump down by the chassis rail where there is normally a metal tube connecting two sections of fuel line. As it’s lower than the tank, the section back along the chassis to the tank needs stopping up otherwise the fuel will empty out.

Stopping up a 2Cv fuel line

I fitted the primer pump in place of the metal tube but, as it’s longer than the tube, I also had to cut down the connecting rubber hose to the chassis fuel line.

2CV fuel primer pump fitting

There’s not much space in this section between the fuel hose clips on the top of the chassis and the one further back in the chassis leg.  It took a bit of adjustment but the primer pump nestles in quite nicely and there are no kinks in the hoses.

2CV fuel primer pump

Admittedly this isn’t necessarily the most practical location for the primer pump as it’s tucked away behind the wheel and exposed to the elements.  However, it’s only going to be needed when starting after having stood for a while so having it tucked out of sight is the more pressing concern.

The second addition is a clear fuel filter between the pump and the carburettor.  This literally gives a window into the fuel system so I can check if the pump is wet or if I need to use the priming pump to push the air through.

I removed a section of the fuel line, roughly the same length as the filter, shortly above the pump so the hose routing stayed the same.  Given the proximity to the exhaust manifold I didn’t want to lengthen the hose here as the extra slack would increase the chance it would come into contact with the manifold with potentially fiery consequences!

2CV fuel filter in-situ

With everything fitted, and the hose clips tightened up, a few good squeezes of the primer pump rewarded me with fuel clearly flowing through the filter and – just as importantly – no leaks.

2CV fuel filter

Removing a 2CV fuel pump

With no obvious fuel leaks the only place left it could be was the fuel pump and associated hoses.

When working on fuel lines always disconnect the battery negative before starting.

First step in removing the pump was to disconnect the fuel line at the chassis behind the near side wheel and plug the line back to the fuel tank.  A catch pan is essential here.  The fuel line from the pump into the carb also needs disconnecting but that doesn’t spill too much fuel.

For an engine where things are normally very accessible the fuel pump is buried behind the fan housing and oil cooler, and tucked under the near side exhaust manifold.

2CV fuel pump burried behind the fan housing

There are two 11mm bolts mounting it to the engine casing but getting to them proved tricky.  As it’s a fair way down extender bars were going to be required – two in fact.

11mm 3/8

With a couple of extender bars being enough to get down to the pump, the1/2″ drive socket was too fat to get past the pump body and get purchase on the nut.  The slimmer 3/8″ drive socket would just get down and get purchase.

Accessing the 2CV fuel pump with the 3/8

With the nuts removed the pump could now be extracted which is easier said than done.  It’s a bit of a 3D puzzle and you need to be careful not to damage the oil cooler fins.

Extracting the 2CV fuel pump

Whilst you’re extracting the pump make sure you keep an eye on the spacer that sits between the pump and the engine block.  Mine ended up wedged behind the cylinder head cooling duct.

With the fuel pump removed it was pretty obvious where the leak was coming from – a perished and split hose at the lower side of the pump.

2CV fuel pump with preished hose

Judging the by the style of the Citroën logos on the fuel hoses they were certainly old, if not even original, so not surprising they had gone – especially as they are in a high temperature environment and pre-dated bio-ethanol fuel addatives.

With the pump removed I cleaned it with the Gunk Green degreaser and cleaned and lubricated the pump drive from the operating lever.

With new fuel hoses and new clips fitted it was time to refit.

2CV fuel pump with new hoses

Refitting was the reverse of removal.  The 3D puzzle to get the pump back into position is no easier in reverse but with newer and less compliant hoses it also means you have to pull the lower hose through as you lower the pump.  After four attempts I managed to figure out the reverse of dropping the spacer behind the cooling duct was to hold it under the pump with the bolts in place and locating it on the mounting – at the second time of asking.

As leaking fuel was a safety critical item I had delayed the freeing of the stuck fan.  With the fan and points shield removed access to the fuel pump mount is significantly improved.

2Cv fuel pump acess through fan housing

Whilst I think I’d still go in from the top to access the mounting bolts, ensuring it’s correctly mounted on the spacer will be much easier with this access.

Whilst trying to fit it back in I found the bonnet stay was getting in my way. Simple solution to this was to slide the bonnet out of the hinge and take it off the car. With no bonnet to support the stay can be unhooked from the mount on the light bar and access is greatly improved.

With everything back in place I turned the engine with the starting handle to get the pump working and try and draw some fuel through but it still took some turning on the starter motor before catching.  The throttle idle also needed adjusting and the timing seems to need adjusting as it runs on for a couple more cycles when turning the ignition off.

No more leaking fuel though.