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Part 7 Brakes
Often braking systems are rebuilt/modified by inexperienced people who could re-assemble the system incorrectly with the resulting dire consequences. On this basis, it is my intention
to only make suggestions as to what modifications can be carried out on the TR 7/8. If you are not experienced in rebuilding braking systems. don't risk your life -enlist the help of a qualified mechanic or a
reputable garage.
As the car, is at least 18 years old, now would be an ideal opportunity to cheek out the complete braking system. REMEMBER. THE ENTIRE SYSTEM IS METRIC -don't be persuaded differently.
1) Cheek the steel brake pipes running to the front and rock of the car -if there is any sign of rust replace them with new piping - preferably with the modem Korfund copper type.
Special in-line connectors are available to make life easier, particularly when running new piping from the back axle.
2) Replace the three flexible pipes -two under the front wings and one to the rock axle. They
probably look in good condition but they may be breaking down inside, remember the system is being uprated!
3) When bleeding the system, always use new brake fluid to the latest specifications -I make no distinction between lockheed fluid
and its silicone equivalent but remember that they must NOT be mixed.
4) Ensure that all components are clean and free from contaminating liquids and dirt Rear Brakes This is probably the simplest
modification but is often missed Assuming that a 5-speed axle is fitted to the car, change the wheel cylinders from the existing one (p/No. GWCI212) to those used on the 4-speed a.xles (p/No. GWCI213). These have a smaller bore and complement the uprating of the brakes at the front of the can They were fitted to
all genuine TR8s and can be obtained from Unipart, Rimmers, S&S and most Triumph dealers. A small modification is needed to the backplate as the locating dowel at the back of the 4-speed wheel cylinder is in a
diametrically opposite position to its 5- speed counterpart (a positive way of establishing that you have received the correct part! Fit the wheel cylinder through the main hole in the back plate, mark the position
of the dowel and carefully drill the correctly sized hole. Remember to fit a new retaining spring clip (p/No. 17H7949) at the back of
the wheel cylinder when re-assembling. To complete the rear brake modifications, fit new 5-speed brake shoes (was P/No. GBS796 now
GBS813) as a complete axle set. When fitting the new brake shoes, particular attention should be paid to cleaning and greasing (with copper ease) of the hand brake mechanism -a little extra time spent now will save
a great deal of time when the MoT is due. As an alternative. I understand S&S are now marketing a back axle fitted with a disc brake conversion. This will obviously give greater stopping power but I have no
details of its effectiveness or cost.
Front Brakes Many stories are circulating regarding what brake parts from other cars can be fitted to the TR7 to uprate them This
ranges from using callipers off scrap Princess/ Ambassadors with TR 7 solid discs to the full house four pot Rover Vitesse vented discs
On the Vitesse stub axle. My only comment is: "if you are sourcing the parts yourself -be careful!"
Having converted my own TR8 to AP four pot callipers and vented discs (with the assistance of Ian Tinsey), I would advocate the
vented type every time for stopping power and resistance to fade when braking from high speed Unfortunately these are now very expensive, so the alternative of four pot callipers with solid discs is a good
compromise providing the car is not pushed too hard. All the alternatives are available from Rimmers, S&S, Moss and, I believe, Robsport. From a safety angle I would opt for one of their kits.
Some of the combinations that I have seen are as follows:
a) Standard TR7 discs with Princess/ Ambassador callipers.
b) So called TR8 discs with Princess/ Ambassador callipers (these are thicker discs than the TR7 ones but are NOT genuine TR8 discs).
c) Princess Ambassador callipers with spacer kits fitted in conjunction with modified Capri 2.8i vented discs.
d) Genuine AP Racing vented discs with four pot callipers as used on the original rally cars.
e) Rover Vitesse assemblies modified to fit the TR7 hub. D Early Rover SOl assemblies complete with struts.
NOTE : Some of these options will require larger wheel rims to allow clearance for the larger callipers.
In all cases extra 'plmnbing' will be required as dual circuit braking systems were incorporated into the original vehicles.
Whatever your decision. make sure that the equipment is correctly fitted.
Master Cylinder and Servo - Again I have seen a number of alternatives, but under most circumstances the standard TR7 servo
and master cylinder are quite adequate. One problem with the standard system is that the pedal travel becomes longer when the four-pot calliper is fitted This can be reduced if the 4 speed rear wheel cylinders are
fitted and the rear brakes correctly adjusted.
Pressure Reducing Valve - This does not normally require attention, however if difficulty is experienced with rear brake
efficiency the valve has probably become sticky and will require changing.
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