Vauxhall Astra Workshop Service and Repair Manuals

Master Brake Cylinder, Overhaul (not with ABS)  

Notice: 

With new master brake cylinders an overhaul is no longer possible.  

GMF version:   Remove master brake cylinder - see operation "Master Brake Cylinder, Remove and Install".     1  Closure cover with warning indicator (EC) contact   2  Brake fluid reservoir   3  Retaining clamps (not contained in repair kit)   4  Gaskets for fluid reservoir (not contained in repair kit)   5  Housing for master brake cylinder   6  Seal ring to brake servo   7  Seal ring   8  Front piston with springs   9  Retaining ring   10  Rear piston with springs

  Disassemble   

Tension brake master cylinder in vice using protective jaws. Lever sealing ring out of cylinder bore. Press piston 10 mm/0.4 in. into brake master cylinder using wooden or plastic drift. Remove retaining ring from brake master cylinder housing using suitable screwdriver.     Important!    Retaining ring is destroyed - use new one. Do not damage piston and cylinder wall.     Disassemble

Remove rear piston from housing. Knock master brake cylinder on wooden base. Press front piston out of housing using compressed air.

  Inspect   

Inspect housing and piston for wear. Clean all parts. With surface damage (rust) on cylinder wall, the master brake cylinder is to be replaced.  

  Assemble   

Coat cylinder bore with brake cylinder paste. Remove closure plugs from installing sleeves. Push short sleeve part flush to cylinder. Insert installing sleeves to collar of small sleeve in cylinder bore.   Insert inner parts of installing sleeve with KM-436 to stop on cylinder floor. If KM-436 is too short, cut off sleeve. Insert rear piston in cylinder with KM-436. Insert new retaining ring in groove of cylinder bore. Press piston into cylinder. Move piston to and fro to check free movement. Coat sealing ring with brake cylinder paste and insert in cylinder bore with open side facing outwards.   Install master brake cylinder - see operation "Master Brake Cylinder, Remove and Install".