M. THE BRAKING SYSTEM .................................................... General description, Maintenance, Pedal, Handbrake, Bleeding the system, Master cylinder, Disc brake units (front), Diagram and key (disc brake components), Discs (front), Flexible hoses, Rear brake assembly, Diagram and key (rear brake components), Relining the shoes, Back-plates (rear), Servo unit (Lockheed Mk 6), Diagram and key (vacuum servo components) MELTHE BRAKING SYSTEM (TANDEM MASTER CYLINDER) ................................................. Pedalfree movement, Tandem master cylinder, Pressure failure switch assembly, Diagram and key (master cyl- inder) N. THE ELECTRICAL SYSTEM .............................................. General description, Battery (dry-charged 7 prepara- tion for service; new, unfilled, uncharged 7 preparation for service), Dynamo, Control box (Model RB340), Starter, Fuses, Windshield wiper 7 single-speed, Dia- gram and key (windshield wiper components), Head- lamps, Side and direction indicator lamps, Tail and stop and direction indicator lamps, Number-plate lamps, Pan- el, map, and warning lights, Relays 7 early cars only, Horn and horn-push, Flasher unit, Diagram and key (switches, regulator and fusebox), Switches, Faults 7 location and remedy, Bi-metal resistance instrumenta- tion, Tachometer (impulse type), Reverse lamps, Elec- trically heated back-light (GT), Cigar-lighter, Charging system (GHN4 and GHD4 cars), Alternator (I6AC, 16ACR), Windshield wiper two-speed, Starter (M418G pre-engaged), Control unit (4TR), Switches (GHNS and GHD5 cars from Car No. 258001), Starter motor (2M100 pre-engaged) _ Na. THE ELECTRICAL SYSTEM (SPECIAL REQUIREMENTS) ....................................................... Diagram and key (the switches), Instruments and switch- es, Windshield washer motor, Lamps, Hazard warning flasher unit and audible warning buzzer, Switches, warn ing lamps and controls Nb.THE ELECTRICAL SYSTEM (WIRING DIAGRAMS) ..... Diagrams and keys for: MGB, positive earth 1962-1964 (Tourer only), MGB, positive earth 1964-1967 (Tourer), and 1965-1967 (GT), MGB, negative earth 1967-1968 (Tourer and GT), MGB, negative earth 1968-1969 (Tour- er and GT), MGB, negative earth 1968-1970 (Tourer and GT), MGB, negative earth 1970-1971 (Tourer and GT), MGB, negative earth 1971-1972 (Tourer and GT). Dia- 245 259 263 303 311 grams and keys for MGB cars fitted with electrical equip ment in conformity with local and territorial regulations: MGB, negative earth 19671968 (Tourer and GT), MGB, negative earth 1968-1969 (Tourer and GT), MGB, nega- tive earth 1969-1970 (Tourer and GT), MGB, negative earth 1970-1971 (Tourer and GT), MGB, negative earth 1971-1972 (Tourer and GT), MGB, negative earth 1971- 1972 (Tourer and GT 7 with seat belt warning) THE WHEELS AND TIRES ................................................ General description, Maintenance, Jacking up the car, Removing and replacing wheels, Valves, Tire removal, Inspection of wheels and tires, Repair of tires and tubes, Fitting tires and tubes, Wheel and tire balance, Factors affecting tire life, High-speed tire pressure conditions THE BODY ............................................................................ Front grille, Bonnet and bonnet lock, Windscreen (wind- shield) (Tourer), Doors and hinges,(trim pad, ventilators, glass, glass regulators, interior handles and window regu- lators, strikers, locks, lock remote control unit 7 later models and GT, outer handles, private lock 7 later mod- els and GT, lock adjustment 7 GHN4/5 and GHD4/5 cars, interior handles and trim pad 7 GHN4/5 and GHD4f5 cars, outer handles 7 GHN4/5 and GHD4/5 cars, locks 7 GHN4/5 and GHD4/5 cars), Seats, Luggage compartment (lock, lid), Rear quarter-light (GT), Glasses 7 windscreen (windshield) and back-light (GT), Fascia, Body alignment, Paint finishing instructions, Alignment check (vertical, horizontal), Bodywork, Bumpers, Elec- trically heated back-light, Seat belts, Heater, Console, Face4level vents, Front grille (later GHNS and GHD5 cars) Ra. THE BODY (SPECIAL REQUIREMENTS) ........................ Console, Fascia, Glovebox and lid, Face-level vents, Seat belts, Anti-burst door units SERVICE TOOLS ................................................................. Illustrations and part numbers of all service tools re quired LUBRICATION CHART ...................................................... Recommended lubricants for each part of car according to varying climates and make of lubricant used ENGINE EMISSION CONTROL SUPPLEMENT .............. Equipment required, Servicing instructions, Crankcase emission control, Exhaust emission control (exhaust port air injection and engine modification system), Carbure- tors, Fault location table, Fuel evaporative loss control system, Tuning data, Tune-up chart 0. R. S. 4 OFFICIAL SPECIAL TUNING MANUAL FOR THE MGB TOURER AND GT A. GETTING THE BEST FROM YOUR MGB ........................ When fitted with an H.C. engine (compression ratio 8.821), Choice of fuel, Sparking plugs, Static ignition settings, Dunlop center-lock wheel, General B. GENERAL DATA ................................................................. Engine, Crankshaft, Main bearings, Connecting rods, Pistons, Piston rings, Gudgeon pin, Cylinder head, Valves and valve gear, Valve guides, Valve springs, Tappets, Rockers, Camshaft, Engine lubrication system, Torque wrench settings, Fuel system, Air cleaner, Fuel pump, Cooling system, Ignition system, Clutch, Gearbox (stand- ard and overdrive), Gearbox (closeratio), Steering, Front suspension, Rear suspension, Propeller shaft, Rear axle, Electrical equipment, Brakes, Wheels, Tires, Fluid capac- ities, General dimensions C. TUNING ................................................................................ Stage 1: Tuning by port polishing (ordinary road work), Stage 2: Tuning for middlerange acceleration (ordinary road work), Stage 3: Compression ratio 9.6 to 98:] (com- petition tune), Stage 3A: Compression ratio 9.6 to 9.811 (competition tune), Stage 3B: Compression ratio 10.5:1 (competition tune), Stage 4: Compression ratio 9.3 to 447 447 451 xi 9.5:1 (competition tune), Stage 5: 9.3 to 9.521 compres sion ratio (Weber carburetor), Stage 6: 10.4 to 10.621 compression ratio (competition tune) OTHER SPECIAL ITEMS ................................................... Brakes, Balancing of road wheel and tire assemblies, Valves and guides, Cylinder head gasket, Valve springs, Rear axle ratios, Closeratio gearbox, Water thermostat and fan, Oil cooler, Fuel pump, Clutch, Crankshaft bear- ings, Crankshaft, Weber carburetors, Fl wheel, Timing chain sprockets, Road springs, Anti-roFl ars, Shock ab- sorbers, Tires and 7tire pressure, Distributor, Sparking plugs, Dynamo, Exhaust system, Fly-off hand brake, Headlamp cowls (Sebring), Engine oil sump, Gearbox dipstick and oil seal, Oil pump, Oil filter, Torque wrench settings COMPETITION EQUIPMENT ............................................ General, Brakes, Suspension, Conversion of early gear- box to large-diameter lay shaft and closeratio gears, Clutch, Engine, Weber carburetor installation, Engine ancillaries, Alternative axle ratios OPTIONAL EXTRAS ........................................................... List of parts with part numbers 327 335 363 369 392 393 452 459 460