Replacing a 2CV’s oil feed pipes

Being an air/oil cooled engine the pipes that feed oil to the 2CV’s cylinder heads are a key part of the system. They take oil fresh from the cooler and distribute it to the cylinder heads where it passes round the exhaust valve sleeve to cool it before entering the rocker covers to keep that area well lubricated, then returning down the push rod tubes to the sump.

The factory fitted steel pipes which, as they carry hot oil and are right at the front of the engine immediately behind the cooling fan, are somewhat susceptible to rust. When carrying out previous work I had noticed that there was a lot of surface rust on them but there’s no way of knowing how structurally compromised they were – and the consequences of a failure would be spraying high pressure oil onto the hot cylinder barrels, a situation that would be classed as far from ideal. A preemptive replacement with new, corrosion resistant, pipes was thus in order.

New copper-nickel 2CV oil feed piples

Whilst replacing them “only” involves three bolts, those bolts are located behind the tinware, which in turn is secured through the front engine mounts. And it’s behind the headlight mounting frame for good measure.

2CV with bonnet and wings removed showing engine

Removing all that lot falls into the category of “not technically difficult but laborious and time consuming”. However, once it’s done, access to the feed pipes is very good.

2CV oil feed pipes highlighted on an engine with the tinware removed 2CV oil feed pipe cylinder head mounting

Removing the three banjo bolts (taking care to track which one came from which location as the one on the block is different to the ones on the heads) allows the pipes to lift off cleanly. Some new copper crush washers that came with the pipes were fitted, these are one – folded – spectacle type piece which are much easier to fit than individual washers that were used on the original.

The banjo bolts were refitted and tightened to a torque of 11 Nm (8 ft lbs) – being steel bolts going into lumps of aluminum this torque is both low and very important to observe. (It’s also less than the lie of 13 Nm printed in the book of lies Haynes manual.)

Whilst you’re here…

Bolts and nuts

With the tinware off it was a good time to do another job whilst the access was good: replace the manifold seals. (TL;DR: unbolt the manifold, lift it up, replace the seals, then bolt back on.)

In order to do that the manifold had to come off which made it a good time to do another job: re-torque the heads. (TL;DR: slacken off the head bolts then re-torque per the manual.)

In order to do that the rocker covers had to come off which made it a good time to do another job: replace the rocker retaining bolts.

After doing that it was a good time to do another job: adjust the valve rocker clearances.

Thanks

Thanks to TomB engineering and the Kung-Fu Panda for their invaluable help with this job.