During the year that my Cortina provided me with daily transport it became apparent that the brakes are actually not that bad and it was quite possible to lock up both front wheels. However, what I did find was that the brakes quickly overheated causing the inevitable brake fade.
The picture above shows the standard front brake set up comprising of a twin pot calliper and a solid disc. You'll notice that unlike modern cars the disc is mounted on the back of the hub as opposed to being sandwiched between the hub and the wheel. Modern cars brakes dissipate a lot of there heat by transferring it to the large alloy wheel bolted against the disc, effectively using it as a heat sink. On older cars such as this the disc has only the iron hub to spread it's heat to and iron doesn't make nearly as good a heat sink as alloy. The other problem is the lack of airflow to allow heat to escape. The disc is solid and there's a debris guard located against it's inner face obstructing the airflow.
The ideal solution would be to fit modern vented discs that locate on the outboard end of the hub and use modern single piston sliding calipers. However, in order to retain your original wheels you may need to reduce the outer diameter lip of the hub to allow a suitable diameter disc to slide over it and you would end up with your front wheels been spaced out giving a slightly wider track. You will also need to fit longer wheel studs. This is all very do-able but there is an alternative option for a road car.
As I stated at the start, the brakes are actualy not that bad when working properly, they just overheat quickly producing brake fade. Therefore we need to improve the cooling to them. There are two things we can do to achieve this, remove the debri gaurds to allow some airflow over the brakes and upgrade the solid discs to vented discs.
No model of Cortina was ever fitted with vented discs so you'll have to find some from somewhere else. The mk2 Granada uses a very similar set-up to the Cortina and the bigger models did use vented discs but they use 5 stud hubs and as a result the discs are also mounted with 5 retaining bolts as oposed to the Cortina's 4. But all is not lost as the Capri 2.8i has vented discs of the correct size and shape and is also of 4 stud hub design. You will have to raid a mk2 Granada 2.8i of it's callipers though as your originals won't fit around the thicker vented discs and the Capri callipers are of a different design.
Capri 2.8i vented front discs
Granada mk2 2.8 front calipers (ensure spaced for vented discs)
Caliper rebuild kit
Granada mk2 2.8 front brake pads
Steel plate for fabricating calliper brackets
Wheel bearing grease (and wheel bearings if you want to replace them)
Bleed, check for leaks, fit the wheels, check for clearance/free to rotate and off you go. In the last set of photos you can see the lug that fouled on my original Ghia alloys and that I had to grind off smooth.
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