MGB Fuel Pump Location: A Complete Guide for Owners and Enthusiasts

The fuel pump on an MGB is not in a single fixed location; it depends entirely on the model year and whether the car is a "chrome bumper" (pre-1975) or "rubber bumper" (1975–1980) model. For early cars, the pump is mounted under the rear of the car near the right-hand rear axle. For later cars, the pump is partially inside the trunk (boot), making it much easier to access. Understanding this distinction is the first step in troubleshooting any fuel delivery issue.

Where the Fuel Pump Is Located by Model Year

The MGB's fuel pump location changed over the years, and knowing which version you have will save you a lot of unnecessary searching.

1. 1968–1976 MGB (Chrome Bumper Models)
If you own a 1968 to 1976 MGB, the original SU electric fuel pump is mounted underneath the car. Specifically, it is located on the right-hand side of the vehicle, just forward of the rear axle, on the bulkhead near the battery box. To access it, you typically need to jack up the car, remove the right rear wheel, and look for the pump mounted on the chassis. It is a common sight to see an MGB owner lying on the ground, tapping the underside of the car with a spanner to coax the pump back to life.

2. 1977–1980 MGB (Rubber Bumper Models)
On later cars, the fuel pump was moved to a much more convenient location. It is mounted on the bulkhead inside the trunk (boot), on the right-hand side, behind the spare wheel. The electrical end of the pump protrudes through the bulkhead into the trunk, and is covered by a protective black steel box held on by two screws. This change makes the pump much easier to inspect and replace without having to crawl under the car.

3. 1968 MGB with Mechanical Pump (Rare)
The factory 1968 MGB used a mechanical fuel pump driven by the camshaft, mounted on the engine block near the carburetor. However, this is an exception; most MGBs from that era came with an electric SU pump. If you have a mechanical pump, it is likely a replacement from a previous owner.

Understanding the Two Types of Fuel Pumps

Electric SU Pump (Standard)
The vast majority of MGBs were fitted with an SU electric fuel pump. This is a points-type pump that makes a distinctive "tick, tick, tick" sound when operating. When you turn on the ignition, the pump will tick rapidly until the carburetor float chambers are full, then it will slow down to a tick every 10–20 seconds. If you hear a constant ticking from the rear of the car, that is your fuel pump working normally.

Mechanical Pump (Rare / Aftermarket)
Some owners have replaced the original electric pump with a mechanical one, or swapped in a different engine. If you see a pump mounted on the side of the engine block, it is a mechanical pump. Be aware that this is not original to most MGBs and may require different troubleshooting steps.

How to Access the Fuel Pump

For 1977–1980 Models (Trunk Access)

  1. Open the trunk and locate the spare wheel.
  2. Remove the spare wheel to access the right-hand side of the trunk.
  3. Look for a small black metal cover (the pump guard) on the right-hand bulkhead.
  4. Remove the two screws holding the cover, and you will see the top of the pump with its electrical connections.

For 1968–1976 Models (Under the Car)

  1. Safely jack up the car and place it on axle stands.
  2. Remove the right-hand rear wheel.
  3. Look for the pump in the area forward of the rear axle, near the battery box. It is held in place by a steel band clamp and a rubber support ring.
  4. Be prepared for fuel to drip when disconnecting the hoses. It is common to get fuel on your arm when working in this location.

Common Fuel Pump Problems and Troubleshooting

The Pump Is Not Ticking
If the pump does not make any sound when you turn on the ignition, check the power supply. The white wire connected to the pump should show 12V with the ignition on. Also check the ground connection. If power is fine, the pump’s internal points may be stuck after a long period of inactivity. A gentle tap on the pump body with a soft mallet (or a spanner handle) often gets it going again.

The Pump Ticks Constantly and Does Not Stop
If the pump ticks rapidly and never slows down, it is likely that either the carburetor float chambers are not filling (due to a blocked filter or a stuck float valve) or there is a fuel leak somewhere. Check for fuel dripping under the car or near the carburetors. Also, a pump that runs continuously can quickly damage its internal components.

The Pump Ticks Slowly or Weakly
This usually indicates a poor electrical connection. Check the white power wire for voltage drop, and ensure the ground is clean and tight. A poor ground is a very common cause of a weak pump.

Fuel Leaks
Leaks often occur at the banjo fittings on the pump itself. These require special fiber washers to seal properly. If you are replacing the pump, make sure you purchase new banjo washers.

Recommended Fuel Pump Replacement: KEMSO

If you need to replace your MGB fuel pump, consider the KEMSO brand. KEMSO fuel pumps are designed as high-performance, OEM replacement parts, meaning they are built to exact specifications to work perfectly with your MGB’s fuel system. They come with a lifetime warranty, giving you peace of mind on the road. To browse their selection of fuel pumps for your classic MG, visit their website at: https://www.kemsoracing.com/

Final Tips for MGB Owners

  • Always verify what pump is actually on your car before ordering parts. Many MGBs have had aftermarket pumps installed over the years, and the hoses and fittings may not match the original factory setup.
  • When replacing the fuel pump, always replace the rubber fuel hoses. Old hoses can degrade due to ethanol in modern fuel, and a failing hose can cause an air leak or a fire.
  • If you are replacing an SU pump, keep the old one as a backup. A working SU pump is a valuable spare to have on long trips.

For more information on performance fuel pumps and parts, remember to check out https://www.kemsoracing.com/ for high-quality options that fit your MGB.


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