Front & Rear Brakes

Click to go to Part 1

On removing the Cortina’s rear drums I discovered that the brake shoes were serviceable but one of the wheel cylinders was partially seized. I am not a believer in fitting new seals to 40-year-old hydraulics, so I decided to replace the wheel cylinders on both sides. As it was unlikely that brake pipes would oblige and unscrew easily the best plan was to replace the pipes as well. Wheel cylinders were bought from Firstline via eBay for £9.00 each and brake pipes made to pattern by a local garage.

Different wheel cylinders were used on the Mark 3 Cortina during it’s production dependent upon year, model and engine size. Significant changes were made to the rear brakes from 1973 onwards and little will interchange with earlier cars. The wheel cylinders supplied by Firstline were exact replacements and fitted, together with the new pipes, with a minimum of fuss. The handbrake cables and  linkages, pivots and self adjusting mechanism were all in good order so the brake drums were replaced awaiting bleeding.

Brake Cyl NSR Inner3

Rear Wheel Cyl (1)

The front brake strip-down showed the pads and discs to be ok; however I decided to remove the pads to check the calliper pistons. Having removed them and gently pressing the brake pedal down there was no movement, more force and the pistons moved enough to close the gap and stop me putting the pads back in. An hour later, and the use of large crow-bar, I had managed to push the pistons back sufficient to insert the pads. Having changed many sets of pads over the years experience told me that gentle force with a short bar moves the piston back into the calliper. Substitute laying on the drive with both feet on the hub and pulling wildly on a crow bar! Clearly something was not as it should be.

Front Brakes  (4)The callipers looked original equipment and the ten years of dry storage had done them no favours. Brake fluid, although it is oil, has the ability to absorb water from the atmosphere. Modern service schedules require brake fluid changes every few years but this was uncommon thirty or forty years ago. Possibly the frequency with which seals leaked back then resulted in brake fluid being replaced quite often anyway. As a point of interest most garages can check the water content of brake fluid quite easily. A small sample of the fluid is taken from the reservoir and heated until it boils, the lower the boiling point the greater the water content. Pure water boils at 100⁰C, brake fluid with no absorbed water may be double this. High water content in the brake fluid can not only cause metal parts to corrode but, under heavy braking, the heat generated may cause the fluid to boil or vaporise causing brake failure.

Back to the Cortina: It’s my guess that the lack of use and old brake fluid had caused the pistons to corrode and seize. The brake fluid in the reservoir was cloudy and not at all as it should be. Replacements were required. Most replacements these days are refurbished units and there are a number of companies that provide quality products. When ordering, a surcharge is payable against the return of your old units. I sourced two refurbished callipers from  Brakes International for £139.40 including the surcharge of £36.00.

This £36.00 was dented somewhat by the cost of posting them back. Weighing just over 10 kg postage cost nearly £16.00. The old returned parts must be complete with no broken lugs etc.They will be inspected before the surcharge is repaid. The company websites generally list what is and what isn’t acceptable. Despite postage costs it is important that old units are returned, as these provide the basis for future refurbished units. Without them we would struggle to obtain quality spares.

The new callipers arrived promptly and fitting commenced. The mounting bolts also hold the Tab Washer Templatebrake hose bracket in place. This bracket has tabs that fold over onto the flats of the securing bolts to prevent them from coming undone. One of the nearside tabs broke off. A spot of fabrication was now required. Using a scrap piece of metal a new locking tab was sawed, filed and drilled until a functional, if not particularly pretty, component emerged. This fitted between the brake hose bracket and the bolt heads. Prior to fitting I placed it on a sheet of paper and sprayed black paint over it. I now had a painted bracket and a paper template for future use.

Fluid is fed into the callipers by a short length of intricately shaped brake pipe; this snapped off when I undid the unions. Another trip to the local garage for new brake pipes to be made. Whilst waiting for the callipers I ordered two new front brake hoses to replace the aging ones fitted. Three of the four nuts, which hold the two brake hoses to their brackets, came undone with the application of WD40 and Herculean strength, the fourth one had to be sawn off, but at last all parts were removed and new ones were ready to fit.

IMG_0042Fitting the new ones proved less stressful than removing the old one. The only snag was that the new brake hoses were supplied without the securing nuts so another trip to the local garage was required to raid his useful bits and bobs selection of nuts and bolts. At last two new callipers, brake pipes and hoses were fitted and I was ready for the next stage. The master cylinder.

To be continued!

Click to go to Part 3