Target Audience:
Mini 1275 GT owners and enthusiasts, DIY mechanics, restoration specialists
Value Proposition:
Provides professional-level repair and maintenance information, enabling significant cost savings on labor.
Authenticity:
Genuine factory documentation, ensuring accuracy and completeness.
Accessibility:
Instant digital download, eliminating shipping delays and costs.
Usability:
Printable, searchable PDF format for easy information retrieval and on-demand use.
Primary Coverage:
Mini 1275 GT (1969-1980)
Secondary Coverage:
General Mini Cooper S (Mk3/Mk4, 1275cc)
Estimated Page Count:
Hundreds of pages (Exact number not specified, but described as 'complete' and 'hundreds')
Manual Type:
Factory Service Repair Manual
Authenticity:
Official Factory Manuals (Not 3rd party)
Delivery Method:
Digital Download
Engine Service Repair:
Yes
Transmission Service Repair:
Yes
Fuel System:
Yes (includes Fuel Injection / Fuel System)
Drive Axle Differential:
Yes
Heater Air Conditioning:
Yes
Engine Control System:
Yes
Periodic Lubrication:
Yes
Maintenance Procedures:
Yes
Troubleshooting:
Yes (Advanced Troubleshooting Guide)
Repair Procedures:
Yes (Step-by-step)
Rebuilding Refurbishment Restoration:
Yes (Covers all aspects)
Tuning:
Yes (Includes tuning)
Depth Of Coverage:
Complete Factory Service Information (same as professional technicians)
Detail Level:
Incredibly detailed, step-by-step instructions, diagrams, photos, illustrations, notes, cautions, warnings
Engine Type:
Inline 4-cylinder, OHV
Displacement:
1275 cc (77.8 cu in)
Bore X Stroke:
70.61 mm x 81.28 mm (2.78 in x 3.20 in)
Compression Ratio:
Varies by specification, typically 8.8:1 or higher
Horsepower:
Approximately 59-65 bhp (net) at 5500-6000 rpm (specific figures vary by market and exact tune)
Torque:
Approximately 70-75 lb-ft (net) at 3000-3500 rpm (specific figures vary)
Fuel Delivery:
Twin SU Carburetors (e.g., 1.5 inch HS4) or potentially Lucas Fuel Injection in later models/specific markets, though twin carbs were standard for the GT.
Fuel Type:
Unleaded gasoline (post-lead removal)
Oil Capacity:
Approx. 4.5 liters (4.8 US quarts) with filter change (check manual for precise specification)
Oil Viscosity:
Typically 20W-50 or 10W-40, depending on climate and period recommendations (manual will specify)
Transmission Type:
4-speed manual transaxle
Optional Transmission:
None typically offered for the 1275 GT model specifically
Gear Ratios:
Detailed in manual; generally includes close ratios for sporty driving.
Transmission Fluid Type:
Hypoid Gear Oil (e.g., SAE 80W-90) or specific manual gearbox oil (check manual for specification)
Transmission Fluid Capacity:
Approx. 1.8 liters (1.9 US quarts) (check manual for precise specification)
Length:
Approx. 3076 mm (121.1 in)
Width:
Approx. 1408 mm (55.4 in)
Height:
Approx. 1316 mm (51.8 in)
Wheelbase:
Approx. 2032 mm (80.0 in)
Curb Weight:
Approx. 680-700 kg (1500-1540 lbs)
Gross Vehicle Weight Rating:
Not explicitly stated, but estimated around 1000 kg (2200 lbs)
Crash Test Ratings:
Not applicable by modern standards; vehicles of this era were not subjected to the same rigorous testing.
Braking System:
Front disc brakes (typically 7.5-inch or 8.4-inch depending on spec), rear drum brakes.
Seat Belts:
Lap belts standard; inertia reel or three-point belts may have been optional or fitted during upgrades.
Body Structure:
Unitary construction with integral safety cage elements (inherent Mini design).
Oil Change Interval:
Typically every 3,000-5,000 miles or 6-12 months, as per manual recommendations. Older vehicles may require more frequent checks.
Tune Up Interval:
As needed, but regular checks of spark plugs, ignition timing, and carburetor settings are recommended every 6,000-12,000 miles.
Coolant Type:
Ethylene glycol-based antifreeze (typically 50/50 mix with water). Specific concentration and type detailed in manual.
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid (check manual for specific DOT rating and type).
Rust And Corrosion:
Common on all Minis of this era, particularly around wheel arches, sills, floor pans, and subframes.
Hydrolastic Suspension Leaks:
While not fitted to all 1275 GT models (some had conventional rubber cones), leaks in the interconnected suspension fluid system can occur if not maintained.
Gearbox Synchromesh Wear:
Can experience wear, leading to difficulty engaging gears or crunching sounds, particularly in 2nd and 3rd gear.
Engine Gaskets And Seals:
Oil leaks are common from the crankshaft seals, gearbox main shaft seal, and valve cover gasket due to age and material degradation.
Maintenance Schedule Overview
Preventive Maintenance:
Regularly check fluid levels (oil, coolant, brake fluid, clutch fluid), tire pressures, suspension and steering components, brake wear, and look for any signs of leaks or corrosion.
Manufacturer Origin:
British Motor Corporation (BMC), later British Leyland (BL)
Predecessor:
Mini Cooper S models
Development Purpose:
Designed as a sportier, more powerful variant of the Mini, bridging the gap between standard Minis and the rally-focused Cooper models.
Key Distinguishing Features:
Larger 1275cc engine, flared wheel arches, sportier interior, performance-oriented tuning.
Production Location:
Longbridge, Birmingham, UK
Production Period:
1969-1980
