1973 MG MGB Cooling System Parts

This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator. Read more

17 Coolant / Antifreeze parts for the 1973 MG MGB come from 4 brands — PEAK, PRESTONE, FVP and 1 other brand. The "Popular" part is FVP MV5050GAL. Every part fits both the 1.8L L4 and the 3.5L V8.

In the Compatible With All Colors grade, PRESTONE supplies 1 part: grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. A representative part number is PRESTONE AF3055.

The Economy section lists 4 options from FVP, PRESTONE, PEAK and 1 other brand — the catalog's value-priced group. FVP MV5050GAL is listed in this group.

In the Heavy Duty grade, VALVOLINE supplies 1 part: rated for severe service. A representative part number is VALVOLINE ZXG051.

In the Premium grade, PRESTONE and PEAK supply 5 parts: a step above OE specification in materials, tolerances or warranty terms. A representative part number is PRESTONE AF2100.

In the Standard Replacement grade, PEAK, FVP and PRESTONE supply 6 parts: built to original-equipment specification. A representative part number is FVP GREEN5050GAL.

This table covers the adapters used to pressure-test this cooling system. Read more

2 Cooling System Tester Adapter parts for the 1973 MG MGB come from 2 brands — ACDELCO and MOTORAD. Every part fits both the 1.8L L4 and the 3.5L V8.

This group includes ACDELCO 12A01 and MOTORAD 3003.

This table covers the caps that hold system pressure at the radiator or reservoir neck. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable. Read more

4 Radiator Cap parts for the 1973 MG MGB come from 3 brands — MOTORAD, ACDELCO and CALORSTAT. 3 parts fit every engine; the other 1 is engine-specific.

In the Locking Replacement grade, MOTORAD supplies 1 part: grouped under the catalog's "Locking Replacement" designation — the notes column spells out what sets them apart. A representative part number is MOTORAD ST9.

Standard Replacement: 3 parts, from ACDELCO, CALORSTAT and MOTORAD. A representative part number is ACDELCO RC6.

This group includes MOTORAD ST9, ACDELCO RC6 and CALORSTAT RC0060 and the remaining parts above.

This table covers the upper, lower and connecting hoses between radiator, engine and reservoir. Typical signs include swelling, cracks, a soft spot, or a leak at a clamp. Replace adjacent aged hoses while the system is drained — they share the same heat cycle. Read more

3 Radiator Hose parts are listed for the 1973 MG MGB, from ACDELCO, GATES and ÜRO PARTS.

Economy: 2 parts, from ACDELCO and GATES. A representative part number is ACDELCO 31608.

The Standard Replacement section: 1 option from ÜRO PARTS. ÜRO PARTS GRH305 is listed in this group.

Part numbers include ACDELCO 31608, GATES 25249 and ÜRO PARTS GRH305.

This table covers the senders that report coolant temperature to the gauge or ECU. Typical signs include a gauge that sits on empty or overheat, or a lamp that does not match what the engine is doing. Rule out the cluster and the wiring before replacing the sender. Read more

This group shows a single part: STANDARD MOTOR PRODUCTS TS233.

This table covers the thermostats that open the coolant circuit at the specified temperature. Typical signs include slow warm-up, a gauge that climbs in traffic, or heat that never quite arrives. Replace the housing gasket with the thermostat and bleed the system so a trapped air pocket does not cook the new part. Read more

25 Thermostat parts are listed for the 1973 MG MGB, from MOTORAD, GATES and BECK/ARNLEY. MOTORAD 2000160 carries the "Popular" badge.

Economy: 5 parts, from MOTORAD and GATES. A representative part number is GATES 33508.

The Heavy Duty section: 3 options from MOTORAD. MOTORAD 5200160 is listed in this group.

In the Performance grade, MOTORAD supplies 4 parts: engineered beyond original-equipment specification. A representative part number is MOTORAD 2000160.

The Premium section: 3 options from MOTORAD. MOTORAD 7200180 is listed in this group.

The Standard Replacement section: 10 options from MOTORAD, BECK/ARNLEY and GATES. MOTORAD 200195 is listed in this group.

This table covers the seals at the thermostat housing and water outlet. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

5 Thermostat / Thermostat Housing / Water Outlet Seal parts for the 1973 MG MGB come from 5 brands — GATES, BECK/ARNLEY, MAHLE / CLEVITE and 2 other brands. The "Popular" part is GATES 33655.

Listed part numbers: GATES 33655, BECK/ARNLEY 0390004 and MAHLE / CLEVITE C24093, plus the other parts above.

This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off. Read more

4 Water Pump parts are listed for the 1973 MG MGB, from FVP, US MOTOR WORKS and GMB.

Economy: 2 parts, from FVP and US MOTOR WORKS. A representative part number is FVP US9082.

The Standard Replacement section: 2 options from FVP and GMB. FVP 1131050 is listed in this group.

Listed part numbers: FVP US9082 and FVP 1131050, plus the other parts above.