7-2. SERVICE BRAKE SYSTEM BLEEDING INSTRUCTIONS
This task covers:
a. Pressure Bleediig
c Master Cylinder Bleeding
b. Manual Bleeding
mechanics tool kit:
automotive (Appendix B, Item 1)
Brake fluid (Appendix C, Item 18)
One assistant (task b. only)
l Hood raised and secured (TM 9-2320-387-10).
l Master cylinder filled to proper level
(para. 2-12, item 11).
General Safety Instructions
Always wear eye protection when bleeding brakes.
Always wear eye protection when bleeding brakes. Failure to do
this may cause injury if brake fluid comes in contact with eyes.
l If only the front or rear half of the system has been serviced, it is
usually necessary to bleed only that half of the system. However, if
a firm brake pedal cannot be obtained after bleeding, it will be
necessary to bleed the entire system. The brake hydraulic system
can be bled manually or by using a pressure tank and adapters.
Each method is outlined in the following procedures.
l Bleed brakes in the following order. right rear, 1eR rear, right
front, left front.
a. Pressure Bleediug
l When using a pressure bleeding tank, follow the manufacturers
instructions for its use. Do not exceed the recommended working
pressure when pressurizing the tank. A tank pressure of X5-20 psi
(103-138 kl?a) is sufiicient to bleed the brake hydraulic system.
Release all air pressure from the tank after using it.
l A&er refilling pressure bleeding tank with silicone brake fluid, let
tank sit undisturbed for 30 minutes minimum to ensure all visible
as well as minute air bubbles are gone.
This procedure covers bleeding at one wheel. Repeat bleeding task
for remaining wheels.
Remove cover from master cylinder (1).
Install pressure tank bleeder adapter (2) on master cylinder (1).
Connect line (3) from pressure tank to adapter (2).
Remove protective cap (5) from bleeder screw (6) on caliper assembly (7).
Connect short piece of hose (8) to bleeder screw (6) and place other end of hose (8) in container
3/4-f& of brake fluid.