Rear Brake calipers

With the refurbished driveshafts now installed back into the chassis I can turn my attention to fitting the rear brake calipers.

I have elected to run with discs all round the vehicle so although the sierra donor was drum braked on the rear, converting to discs is a straightforward option.


You will need to order some rear caliper mounting brackets from GBS which fit to between the hub carrier and rear uprights. These in turn support the brake calipers via x2 M10 bolts (approx 40mm)

Brake calipers....this was a frustrating delay more through my own lack of knowledge on Sierra calipers and general guidance out on the web.

What you will need are Sierra Cosworth 4x4 brake calipers NOT Sierra Cosworth brake calipers - spot the subtle difference...yep "4x4" it does make a difference believe it or not. The standard rear discs are 22mm thick, these are too thick for the standard sierra cosworth calipers, which I discovered much to my annoyance when I came to fit! grrgghh

So what was initially a two week lead time on the calipers turned into a four week lead time by the time I had returned the incorrect ones and the supplier had sourced the correct set.

I must mention at this point the service provided by Biggred - they provided an excellent service, the quality of parts I got from them were first class and are well worth checking out both on their ebay shop and company website.

So once received, its a simple case of fitting the disc onto the hubs which in turn is secured with a wheel nut. Marry the caliper to the mounting brackets (you will have to file the carriers and remove the powder coat as the disc will foul in the caliper otherwise)

Once that is done, you can connect the brake cable to the caliper, via simple hook and eye connection and screw in the brake line, job done!

rear brake pipes

Whilst waiting for the heavy labour to arrive and provide assistance to the differential fitment thought i would turn my mind to the rear brake pipe installation.

so what comprises the rear brake pipes..?

4 way brass union
x2 copper brake lines with male and female unions
x2 braided brake hoses 

Working in sequence, the 4 way brass union requires an 8mm hole through which a bolt with Nyloc nut holds the union onto the chassis. The existing hole in the chassis that the union should fix through is 10mm which is puzzling of GBS to provide when trawling the market for brake unions there does not seem to be a fitting which has a 10mm mounting point...

so new hole needs to be drilled to accommodate an 8mm bolt which I duly positioned top right of the existing hole. Simple drill, bolt on and job done.

Onto the copper lines next which run left and right from the brass union to the chassis mount point where in turn the braided hose connects to the chassis. These two pieces are quite short and a good starting point in which to practice the art of copper pipe bending.

Clearly there is a knack to this as the first one I did was distinctly average in its final look and I elected to replace with a new one - if a jobs worth doing right...

Lessons learned:

1. Don't strive to follow the chassis precisely, this approach does not work
2. Start with the copper brake pipe screwed into the union as that acts as a fixed point from which to bend / form and get the pipe to meet with the hole leading to the braided brake pipes.
3. Use a pipe bending tool to get a nice curve in the pipe plus it saves sore fingers doing bends!

with this knowledge in mind the second pipe running left from the union is one I am far more pleased with and is now ready for final fitment and p-clipping to the chassis.

in terms of the braided hoses, the hole in the chassis needs cleaning out with a 10mm drill bit to remove the powder coat and provide better clearance for the end of the braided hose to come through the chassis and fix in position / connect to the copper brake pipe.

so progress made on the rear brake pipes.