With the rear end properly started with the install of the diff, it’s now time to crack on and get the de Dion tube assembled and fit the brake pipes. The brake pipes arrive as two shaped copper pipes which run along the de Dion tube, and which must be fitted before the tube is inserted into the chassis. Also it’s time to loosely attach the ears and calipers.
The process is fairly simple, only slightly helped by a tiny diagram in the assembly manual showing an exploded view of the ear/hub/caliper assembly. Everything went together as planned for me, apart from two bolts I could not locate in the same pack as all of the others. One email to Derek later and I was able to find them: in the misc metric pack. As usual, the guide was a little misleading here.
I found the diagrams from Andrew’s blog a great help again, reproduced below – much more than anything in the manual. The key is using the right bolts, unsurprisingly.
With the ears and calipers loosely fitted, the way in which the brakes operate became obvious. I’d expected the caliper to be fixed (especially as it is connected with a rigid pipe) but it is the bracket holding the pads which is bolted to the ears. The caliper body itself moves. I found a decent explanation for the uninitiated like me at Alcester Racing Sevens web page: it’s an oldie but goodie.
Fitting the pipes gave me an initial worry – I could not see the holes that are pre-drilled for the rivets and there are strict instructions in the guide not to drill others. After a few seconds of searching and wondering where all the Dinitrol on my hands was coming from, it dawned on me: the waxy stuff had filled the holes when I’d sprayed it on the inside of the tube about a month previously. I also needed to run a drill through the holes to widen them slightly for the rivets, but nothing of any real consequence.
Riveting the pipe was a 30 second job in the end. I’m now an experienced riveter (!) so I placed them in position, fiddled with the alignment of the pipes and then popped them. Job done. With hindsight, what I should have done now is bend the ends of the pipe to fit the calipers while I had unrestricted access. I didn’t though, and I’m not sure why. Caught up in the moment I suppose.
I quickly stripped the de Dion back to the pipe plus brake pipes, taped some cardboard on the rear chassis arms, and set about man-handling it into the space at the back of the car. This bit was not as easy as I thought it would be: space is tight between the diff and the chassis and the de Dion is heavy. I managed after about 5 minutes of huffing and puffing, but would shout someone in to help next time.
Next step: unwrapping the rear dampers and drive shafts before fitting. Suddenly, the box that has been the largest and heaviest from the start is empty. The build is moving on apace.