TM  10-3930-638-24&P 2-43. SERVICE BRAKE MAINTENANCE (cont) c. Hydraulic Brake Valve (cont). (2) Power Assist Unit (cont). STEP LOCATION ITEM ACTION REMARKS REMOVAL 1 Front chassis, a. Rubber cover (1) Grasp and pull From gland (2) bottom left side b. Four cap screws (3) Loosen and remove Support body (5) and lock washers (4) c. Power assist unit Remove Pull straight from bracket until clear of body (5) push rod (7); then lower and remove from vehicle d. Rubber cover (1) Remove  and From push rod (7) discard DISASSEMBLY 2 Power assist unit a. Body (5) Position and clamp In vise, with gland (2) facing upward WARNING Exercise care when removing gland (2). There will be spring ten- sion against the gland. Failure to do so may cause gland to fly into your eyes. b. Gland (2) Loosen and remove Turn counterclockwise using spanner wrench or chain wrench and pull from body  (5) c. Spool (9), piston Remove Pull  from  body  (5) (10) and spool cap (11) d. Piston (10) Remove From  spool  (9) e. Piston ring (12) Remove  and Use piston ring pliers discard f. Spring retainer(13) Remove Pull from body (5) and  spring  (14) g. Body (5) Reposition  and In vise, with gland end facing down clamp h.  End  plug(15) Remove From body (5) i. O-ring ( 16) Remove  and discard j. Spring (17), shim(s) Remove From body (5) (18) and poppet (19) NOTE Spring (17) and shim(s) (18) are matched set. Retain shim(s) for reassembly  with  original  spring  (17). 3 Gland (2) a. O-ring (20) Remove  and From gland (2) discard b. O-ring (21), U-cup Remove  and From bore in gland (2) seal (22) and backup discard ring (23) 2-304

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business