With the freshly coated cam cover fitted last week, there was one item remaining to finish the under bonnet area of the DHC. As with the cam cover the car's header tank had also been coated using VHT wrinkle paint. And on the header tank it had faired the same as on the cam cover, it had started to peel off. As it looked after removal from the car ...
So a spare from the shed had been prepared a few weeks ago. And this weekend I had some spare time to fit it. I rather dreaded this job as it means draining part of the coolant from the engine, which is always messy. But I managed to keep the coolant spillage to a minimum. To start with the coolant level in the system was a bit low. And by slightly undoing the clips from the hose between the header tank and the radiator, I was able to move the header tank to the other side of the bonnet stay, while still being connected to the radiator. This way it was above a drip tray, strategically placed on the chassis beam This enabled me to remove the header tank from the hose and turn the hose upwards without any spills, thus creating a high point. This very effectively prevented the remaining coolant from draining away. Only a few drops of coolant escaped from the radiator side of the hose, while I performed the next stage of the job, fitting the refurbished header tank.
Which was very straightforward. The only (small) issue I encountered was when I wanted to take out the drip tray. Turned out there wasn't enough room to manoeuvre to get it out without spilling the coolant it contained. Luckily easily solved by scoping out the coolant with a small cup.
With the engine bay more or less finished I went for a little experiment, bleeding the brakes by gravity! While replacing the rear brake cylinders I found out that the brake fluid drained very easily from the system when I undid the first pipe. So would it be possible to bleed the system in the same way? Well after undoing the bleed nipple on the back axle nothing happened. Which wasn't much of a surprise. Due to the air in the (narrow) system the resistance is too big for gravity to overcome. But pressing the brake pedal a few times to start the fluid flow did the trick. After a few minutes the first fluid emerged from the bleed nipple. And soon after that there were no more air bubbles coming out. Looks like it is working. But as I don't trust blindly on experiments with the brakes, a traditional bleeding session will be carried out to verify that all the air is out of the system. To be continued.