Part Number: A702T0002A
Version: 6
Exige V6 Cup Car
Supplementary Manual
- 20 -
6.0 BRAKE PAD BEDDING IN PROCEDURE
Why bedding?
•
To transfer a layer of friction material onto the brake disc faces to achieve maximum performance.
•
To stabilise compressible materials to avoid a spongy pedal.
•
To boil off volatile elements in the friction compound in order to have the initial ‘green’ fading during bedding and
not during the race.
•
To align the pad surface with the brake disc surface to have full contact.
If pads are not bedded in properly and / or are used hard right out of the box, this is likely to lead to pad glazing.
Pad glazing is a condition where the resins in the pad crystallise on both the pad friction surface and the brake
disc surface, resulting in poor stopping performance, brake judder and vibrations. Also rapidly escaping volatile
elements and moisture from the resin would seek an immediate escape route out of the friction compound,
creating small fissures that would lead shortly to cracking and chunking.
FAILURE TO BED THE BRAKES IN PROPERLY IS LIKELY TO RESULT IN POOR STOPPING PERFORMANCE
WHICH COULD CAUSE SERIOUS INJURY OR DEATH.
The pads must be ‘bedded in’ as per AP Racing ‘road’ recommendations before any race or competition use.
For the first 10 miles, light braking from 50/60 mph down to 30 mph if possible in blocks of 5.
Do
not
attempt any high-speed stops down to zero at this point, as only the faces will heat up with the mass
remaining cool along with the mounting area.
Increase the braking pressures similar to stopping in traffic, again avoiding if possible full stops from above 70
mph.
By the time you have completed the first 10 miles as above, the area around the mounting bolts should be a light
blue temper colour. This is a good indication that the correct heat soak has been achieved.
For the next 100 miles gradually increase the braking effort after this full power stops can be used. The disc
should now be an even dark to light blue temper colour, depending on the pad type and the braking effort being
used during the process.
This process
must
be completed before any race or competition use.
At the start of a session use a minimum of one warming up lap for the brakes i.e. gradually increase the effort at each
corner and do
not
drag the brakes under power as in left foot braking.
Use at least one cooling down lap at the end of the session and if possible stay off the brakes.
Do not
leave your foot on the brake when parked in the paddock after a track session. If you do, the hot spot
created by the pad can distort the disc in that localized area causing a high spot, resulting in vibration under
braking.
It is very important to check your brake system thoroughly after race circuit use. Bearing mind a typical race car
on average will cover less than 50 laps of a circuit before being serviced.
Please note that after track use of a vehicle, the handbrake should not be used in order to prevent heat transfer
from the discs through to the pads and brake fluid. It should be noted however that the vehicle should be
otherwise restricted to prevent it from rolling forward or backward. Aggressive braking technique will result in
accelerated disc and pad wear and more frequent service intervals will be required.