Replacing a water pump and dealing with seized bolts

REGARDLESS of fuel type, capacity or age, all our Land Rover engines use a water pump to circulate coolant. It’s belt-driven, usually off the crankshaft, and the drive belt will usually power the alternator, power steering pump, or air conditioning compressor, too. Impeller blades inside the coolant pump push coolant around the sealed coolant system, through the engine water jackets and passages, to the heater, through the radiator to cool, and back into the engine block in a continuous cycle, and at a flow-rate controlled by the engine speed and thermostat.

Water pumps can last for decades if drive belts are correctly tensioned, and if the correct coolant dilution is used and changed at the specified intervals. But they are a moving part, using bearings for the shaft to spin on. Those bearings wear, and can allow movement in the shaft. If left in that condition, bearings can lock up, with the potential for catastrophic engine failure from overheating. Failing bearings are probably the most common reason to replace a water pump, and they create a telltale whining sound. Beyond that, gasket leaks and impeller corrosion can also be reasons for changing a water pump.

James Holmes show us how to change a water pump on this Series I’s 2.0-litre petrol engine, but the process and principle is broadly similar on all Series, Tdi Defender and Discovery, Range Rover Classic and P38A models. Later engines are more tightly packaged, so can be slightly more involved, though the basic principle is the same, and the likelihood of shearing bolts is greatly reduced.

The one key thing we’re pointing out here is how to deal with the most common issue associated with this job: corroded water pump fixings shearing off