MG MGB Workshop Manuals and Repair Manuals

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MG MGB

The MGB is a two-door sports car manufactured and marketed by MG Cars and its successors as a four-cylinder, soft-top roadster (1962-1980) along with variants including the MGB GT three-door 2+2 coupé (1965-1974), the six-cylinder roadster and coupé MGC (1967-1969), and the eight-cylinder 2+2 coupé, the MGB GT V8 (1973-1976). All MGBs (except the V8 version) utilized the BMC B-Series engine. This engine was essentially an enlarged version of that used in the MGA with displacement being increased from 1622 cc to 1798 cc. The roadster was the first of the MGB range to be produced. The body was a pure two-seater but a small rear seat was a rare option at one point. In late 1967, sufficient changes were introduced for the factory to define a Mark II model.

MG MGB FAQ's

How can I diagnose a faulty alternator in my MG MGB?

If you suspect a faulty alternator in your MG MGB, start by checking the battery voltage with the engine off and then again with the engine running. The voltage should increase when the engine is running, indicating that the alternator is charging the battery. If the voltage remains the same or decreases, it may indicate a problem with the alternator. Additionally, you can use a multimeter to check the alternator's output voltage and ensure it is within the manufacturer's specifications.

How can I diagnose a faulty fuel pump in my MG MGB?

If you suspect a faulty fuel pump in your MG MGB, start by checking the fuse and relay associated with the fuel pump. If they are functioning properly, you can perform a fuel pressure test using a fuel pressure gauge to determine if the pump is delivering the correct pressure. Additionally, inspect the fuel lines for any leaks or blockages that may be affecting the pump's performance.

How can I diagnose a faulty starter motor in my MG MGB?

If you suspect a faulty starter motor in your MG MGB, start by checking the battery voltage and ensuring it is at an adequate level. Next, inspect the starter solenoid and wiring connections for any signs of damage or corrosion. If the battery and wiring are in good condition, but the starter motor still fails to engage, it may indicate a problem with the starter motor itself. Consult a professional or refer to the repair manual for further diagnosis and replacement if necessary.

How can I fix a non-responsive power window in my MG MGB?

If you have a non-responsive power window in your MG MGB, start by checking the fuse associated with the power window system. If the fuse is intact, it may indicate a problem with the power window switch or the window regulator. Inspect the wiring and connections for any signs of damage or loose connections. If necessary, replace the faulty switch or window regulator to restore the functionality of the power window.

How can I troubleshoot a misfiring engine in my MG MGB?

If your MG MGB's engine is misfiring, there are several potential causes to consider. Start by checking the spark plugs and ignition system for any signs of wear or damage. Next, inspect the fuel system for clogged fuel injectors or a faulty fuel pump. Additionally, check the engine's timing and compression to ensure they are within the manufacturer's specifications. If the issue persists, it may be necessary to consult a professional for further diagnosis.

How do I adjust the clutch pedal in my MG MGB?

To adjust the clutch pedal in your MG MGB, start by locating the clutch adjustment mechanism, typically located near the firewall or on the clutch pedal itself. Use a wrench or pliers to turn the adjustment nut or bolt, which will either move the pedal closer to the floor or away from it. Adjust the pedal to achieve the desired amount of free play, ensuring that there is sufficient pedal travel before engagement. Test the clutch operation to ensure proper functionality after making the adjustment.

How do I adjust the valve clearances in my MG MGB?

To adjust the valve clearances in your MG MGB, start by removing the valve cover to gain access to the valves. Using a feeler gauge, measure the clearance between the valve stem and the rocker arm. If the clearance is outside of the specified range, use a wrench to loosen the lock nut and a screwdriver to adjust the clearance by turning the adjusting screw. Once the correct clearance is achieved, tighten the lock nut and recheck the clearance before reinstalling the valve cover.

How do I bleed the brakes in my MG MGB?

To bleed the brakes in your MG MGB, start by filling the brake fluid reservoir with the recommended brake fluid. Begin with the brake furthest from the master cylinder and attach a clear plastic hose to the bleeder valve. Submerge the other end of the hose in a container partially filled with brake fluid. Have a helper press the brake pedal several times and hold it down while you open the bleeder valve to release any air bubbles. Close the valve, release the brake pedal, and repeat the process until all air bubbles have been expelled and a firm brake pedal is achieved.

How do I change the oil in my MG MGB?

To change the oil in your MG MGB, start by locating the oil drain plug underneath the engine. Use a wrench to loosen the plug and let the old oil drain into a pan. Once the oil has fully drained, replace the drain plug and refill the engine with the recommended amount of fresh oil, ensuring that you use the correct grade and viscosity as specified in the owner's manual.

How do I replace a blown fuse in my MG MGB?

To replace a blown fuse in your MG MGB, start by locating the fuse box, which is typically located in the engine compartment or under the dashboard. Use the fuse diagram in the owner's manual to identify the specific fuse that needs to be replaced. Once you have identified the fuse, carefully remove it using a fuse puller or a pair of needle-nose pliers and replace it with a new fuse of the same amperage rating.

How do I replace a malfunctioning thermostat in my MG MGB?

To replace a malfunctioning thermostat in your MG MGB, start by draining the coolant from the system to prevent any spills. Locate the thermostat housing, typically located at the engine block or cylinder head. Remove the housing, taking note of the orientation of the thermostat. Replace the old thermostat with a new one, making sure to install it in the correct orientation. Finally, reassemble the thermostat housing and refill the coolant system with the appropriate coolant mixture.

How often should I change the transmission fluid in my MG MGB?

It is recommended to change the transmission fluid in your MG MGB every 30,000 to 60,000 miles or every 3 to 5 years, depending on driving conditions. Regularly inspect the transmission fluid for any signs of contamination or discoloration. Replacing the transmission fluid at the recommended intervals helps to ensure smooth gear shifting and prolong the lifespan of the transmission.

How often should I replace the spark plugs in my MG MGB?

It is recommended to replace the spark plugs in your MG MGB every 10,000 to 12,000 miles or every 12 months, whichever comes first. Regularly inspect the spark plugs for any signs of wear or fouling, such as black soot or worn electrodes. Replacing the spark plugs at the recommended intervals ensures optimal engine performance and fuel efficiency.

What should I do if my MG MGB's battery keeps draining?

If your MG MGB's battery keeps draining, start by checking for any electrical components that may be drawing excessive power when the vehicle is off, such as lights or accessories that have been left on. Next, inspect the battery terminals for any corrosion or loose connections. If the issue persists, it may be necessary to have the battery and charging system tested by a professional to identify any underlying faults.

What type of coolant should I use in my MG MGB?

It is recommended to use a high-quality ethylene glycol-based coolant in your MG MGB. Look for a coolant that is specifically formulated for use in aluminum engines, as this will provide optimal protection against corrosion and overheating. Make sure to mix the coolant with distilled water according to the manufacturer's instructions before adding it to the cooling system.