3 Wheeler Brakes
The braking system on this vehicle is complicated, mainly because the rear brake is a cable driven drum brake and the front are hydraulic disc brakes. Combining the two is not easy and there needs to be room for adjustment to allow for correct biasing of the whole system.
There are certain legal issues which arose during research that come into play. This concerns cable driven brakes such as the rear brake on this vehicle. Whenever using Bowden cable (wire rope) it is not suitable to just clamp the cable at both ends, correctly soldered ends need to secure it. It therefore made sense to use a ready made cable if possible. The obvious choice for this is a handbrake cable. However the length required was between 2.5m-3.0m long. Most cables are a little over 1.5m long. After doing some research the best solution was to use a handbrake cable from a transit van. This was 2.8m when fully stretched out. Using long brackets at either end meant it was just long enough.
The following adjuster was made for the rear cable connection. This adjuster also accommodates the handbrake cable. This is the main source of adjustment for the brake bias. On a vehicle like this the brake bias should be 75% on the front and 25% on the rear. This is very difficult to calculate in a situation like this. So it can be roughly tested by moving the car forward in a straight line and applying the brakes with force. If the rear brake locks up then the brake should be adjusted until it doesn't lock anymore.
The front calipers were part of the sierra hub assembly along with the disks and pads. The master cylinder was taken from a VW Polo because this is a non servo assisted cylinder which is ample for this project and keeps everything nice and simple. Copper brake tubing was used to connect the master cylinder to the edge of the car then flexible sierra brake hoses to stretch to the brake cylinder. The master cylinder was positioned just behind the brake pedal so a short rod joins the two together, this can just be seen in the picture below. The rear brake cable also connects to the same pedal.
