SAFARI

34 BRAKES BLEEDING THE HYDRAULIC SYSTEM The process of removing air from the hydraulic pipe line and cylinders is known as “Bleeding”, and it is necessary whenever any part of the system has been disconnected, or the level of fluid in the plastic container has been allowed to fall so low that air has been drawn into the tandem master cylinder. PROCEDURE Carefully clean all dirt from and around the filler cap. Fig.35. Remove the filler cap, fill the reservoir with fresh brake fluid to the lower edge of filler neck. Before commencing bleeding at each bleed screw, remove the dust cap and clean thoroughly. The disc brakes are bled first because although they are closest to the tandemmaster cylinder, the plunger bore are much larger than drum wheel cylinder bores therefore contain a great amount of fluid. Attach the transparent (Vinyl) bleed tube to the left front caliper bleed screw and place the other end of the tube in a clean glass jar containing sufficient brake fluid to submerge the end of the tube. Fig.36 It may be advantageous to bleed the entire system with the engine running. Open the bleed screws by 1/2 to 3/4 of a turn, sufficient to allow the brake fluid to flow freely. Depress the foot pedal slowly throughout the full stroke of the pedal, and allow it to return to its stop slowly. It is always better to close the bleed screw at the end of each downward pedal stroke to ensure full recuperation of brake fluid in the system. There should be an interval of 3 to 4 seconds before making the next stroke.This action should be repeated until bubbles of air cease to appear at the end of the bleed tube. Close the bleed screw immediately after the last downward stroke of the pedal.Whilst the pedal is thus held, securely tighten the bleed screw and remove the tube. Replace the dust cap on the bleed screw. Ensure that the fluid level in the tandem master cylinder reservoir does not fall low enough to cause air to be drawn into the system, throughout the bleeding operation. Fig. 35 - Brake Fluid Container Fig. 36 - Bleeding the Front Calliper Brake