Having sorted out which hose goes where, I started the process of installing the plumbing by connecting the two lengths of hose to the heater control valve. The lengths are specified in the manual as 110mm and 120mm for upper and lower respectively. These were very straightforward to cut to length and install.
Next came the submarine assembly. I had already determined where the submarine needed to be positioned to allow the electrical connections to be made, so then next step was to remove the large diameter end of the "J" hose and measure where to cut the straight length. One end of the short "L" shaped hose was attached to the submarine and then the other end to the lower pipe on the heater control valve.
The next task was to plumb the expansion tank to the T-piece on the side of the engine block and than up to the top connection of the heater control valve. The orientation of the expansion tank is not immediately obvious - the larger diameter on the tank needs to face towards the front of the car. As the tank is rotated on it's mounting, the angle of the seam in the middle of the tank also changes. I guessed that this should be roughly horizontal, which meant that the metal bracket screwed to the plate should be orientated so that the tank mounting tab should point roughly towards the engine block. This in turn meant that the larger connector points towards the offside. The longer "J" hose then needs to connect to the expansion tank and routed over and under the front chassis member and up to the T-piece.
This is where I ran into problems. The longest length of hose in my kit was then not long enough to attach to the T-piece and reach the upper connection on the heater control valve.
The second problem came with the position of the bottom hose. It is quite a contorted piece of pipework and obviously only fits in one way round - however, the end of it does not come close to the radiator connector.
Both of these issues were answered by Caterham Build Support - for both the heater hose and the bottom radiator hose, extensions are required. Two additional connectors (one small plastic and one large aluminium) were supplied. The heater hose is a simple job to use some of the left over pipe to extend it up to the control valve. The existing bottom radiator hose needs to be cut at the right hand end of the stretch running along the top of the steering rack - the aluminium connector is then used to join to a new short right angled hose which then reaches the radiator connector. This is not a particularly neat or gratifying area of the design, but Caterham reassure me that this is standard practice in production and has been for many years on many models.