How to Temporarily Fix a Water Pump Leak

Is your machinery’s water pump leaking, potentially causing costly damage and downtime?

Left unaddressed, a water pump leak can lead to overheating, component failure, and expensive repairs.

Fortunately, there are 3 temporary fixes you can implement to keep your machinery running while you schedule a proper repair.

Use a Radiator Stop Leak Product

A radiator stop leak product can temporarily seal small leaks in the water pump or other parts of the cooling system. These products contain additives that flow to the leak and form a seal, preventing further coolant loss. To use a radiator stop leak product:

Allow the engine to cool completely
Drain some coolant from the radiator to make space for the stop leak product
Add the recommended amount of stop leak to the radiator or overflow reservoir
Top off the coolant level with a 50/50 mix of coolant and distilled water
Run the engine with the heater on to circulate the stop leak through the system

Top Off Coolant

If the water pump is leaking, coolant levels in the radiator and overflow reservoir will be low. Topping off the coolant can help maintain proper levels until you can have the leak repaired. Here’s how:

Allow the engine to cool completely before opening the radiator cap
Check the coolant level in the radiator and overflow reservoir
If levels are low, add a 50/50 mix of coolant and distilled water until the radiator is full and the overflow reservoir is at the “cold fill” line
Replace the radiator and reservoir caps securely
Start the engine and check for leaks

Install a Lower Pressure Radiator Cap

The water pump seal can start to leak if cooling system pressure gets too high. Installing a lower pressure radiator cap can reduce stress on the seal and slow leaks until the pump can be replaced. Radiator caps are pressure-rated, with most stock caps rated at 16 psi.

To install a lower pressure cap:

Allow the engine to cool completely
Carefully remove the existing radiator cap
Install a new cap rated at around 13-14 psi, which is usually the lowest pressure available for most vehicles
Make sure the cap seals and locks into place properly