Russ's TR7 blog: August 2018, FHC jobs start, Front Brakes

Monday, 17 December 2018

August 2018, FHC jobs start, Front Brakes

New Front Brakes

One of the first jobs I wanted to do on the new car when it came back from the bodyshop was to overhaul and upgrade the brakes. Standard TR7 brakes are not as good as modern cars and as it had been parked up for some time they needed work anyway.

Princess 4 pot pad top, Standard TR7 pad below

I decided that the Princess 4 pots like I already had on the DHC were the best cost effective option and would also provide some interchangeability between the cars. I had also previously found a pair of calipers that needed a rebuild on Ebay and bought new stainless steel pistons with a seal kit to do the job. The rebuild is not a difficult job and I also took the opportunity to drill them internally at the same time.

The Austin Princess had brakes with an unusual dual circuit system where two separate pipes fed each caliper. Some folks just link these circuits by an external pipe on the caliper but by drilling to link the two circuits inside the caliper is a much neater job in my opinion.

I pop the pistons out with an air line. This can be a bit dodgy so I use a piece of wood to catch them as you see here. This allows them to come out enough to grip and remove easily.

Pistons are out and caliper halves are split. The bores look good after a quick cleanup so a coat of paint and ready to drill the internal link hole.

I use a 1/8" bit (3.2mm) and drill carefully making sure the bit is straight until it breaks through into the gallery. This will be indicated by hitting the welding rod! Your two separate fluid galleries are now linked inside the caliper.

The new stainless pistons and seals can now be fitted using plenty of red brake grease, and the two halves of the caliper bolted together, not forgetting to include the spacers so they will fit over the vented discs.

Next job was the fit the new vented discs for the calipers to work on. Looking around I found out that Toyota Supra 2.8 1982-86 looked ideal. They are 258mm diameter and 20mm thick and luckily pretty cheap as well. My local machine shop turned me up a couple of adapters to mount them on the TR7 hubs and it all bolted together nicely.