Triumph MAYFLOWER 1951 Instruction Book page 56

Air is compressible, and its presence in the system will affect the working of the brakes.
Whilst the majority of owners will prefer to have these operations carried out by a
Triumph Agent, for the benefit of those desiring to carry out their own running
adjustments, the procedure is as follows:
1. Remove the cover in the floor just to the rear of the brake pedal to allow access to
master cylinder reservoir.
2. Wipe clean the bleed nipple of the brake concerned and fit a piece of rubber tube
over it, allowing the tube to hang in a clean container partially filled with fluid, so
that the end of the pipe is below the level of the fluid (see Fig. 34).
NOTE.—Although with the two leading shoe brakes fitted to the front wheels there
are two actuating cylinders there is only one bleed nipple for each brake assembly.
3. Unscrew the bleed nipple one complete turn with a suitable spanner.
4. The fluid reservoir of the master cylinder must be topped up before commencing the
bleeding operation, and must be kept at least half-filled during the whole operation,
otherwise more air will be drawn into the system via the master cylinder. Always
clean the area around the plug before removing it, this will lessen the risk of grit
falling into the chamber after removal of the plug. Seven to eight strokes of the
pedal will reduce the fluid level from full to half-full.
5. Depress the brake pedal quickly and allow it to return without assistance.
Repeat this pumping operation with a slight pause between each depression of the
pedal. Observe the flow of fluid being discharged into the glass jar and when all air
bubbles cease to appear, hold the pedal firmly down and securely tighten the
bleed nipple.
NOTE. Depending upon the position at which a pipe joint has been uncoupled it will be
necessary to bleed the system at either both the front or both the back wheels. If the pipe
was uncoupled at the master cylinder then the system must be bled at all four wheels.
RUNNING ADJUSTMENTS—Brakes
55