There are two reasons why a water pump can fail: a leaking shaft seal and a damaged impeller. In some vehicles, the water pump will stop leaking once the engine cools down and will start leaking again once the engine reaches its operating temperature.
Gasket or Seal Failure: The gasket or seal used between the water pump and the engine block may be defective or improperly installed. If the gasket was damaged during installation or if the surface was not cleaned properly, it can cause leaks.
When a water pump is new, minor seepage from the bleed port is normal as it takes about ten minutes of operation for the pump's internal mechanical seal to seal properly ( break-in period).
An improper seal or misaligned gasket can hurt the performance of the pump. For example, improper installation also causes immediate leakage from the mounting surface. Also, avoid re-using old seals and the wrong seal.
If your pump is leaking from the back side of the pump it is normally caused by this seal being worn or deformed. Usually caused removing or installing your impeller with improper tools. Any type of side pressure on the impeller pump shaft may distort this seal causing a leak.
Make sure there is no air in the cooling circuit by constantly checking that the expansion vessel is within the minimum and maximum levels. Temporary pressure variations caused by air might cause a hydrostatic imbalance in the dynamic seal, causing a temporary leakage.
A worn shaft seal is the most common reason behind a leaking water pump.
Look at the factory specifications for your pump and ensure that it is receiving the correct electrical power supply in order to work properly. Ensure that all electrical wiring is in good condition, that there are no loose connections and that the electrical current is reaching your pump in the first place.
Another sound a broken impeller makes is a screeching noise, possibly due to water pump bearings going bad. Besides unusual noises like grinding, rattling and screeching, other signs that an impeller has gone bad include water pump leakage, reduced water pump flow, slow engine re-priming and engine overheating.
If you notice leaks after replacing your car's water pump, make sure the pump was installed properly. This may mean taking it back to the shop or giving it and the connections a thorough inspection if you installed the pump yourself.
Driving with a bad water pump, especially if it's blown, is not advisable. Get a Professional Assessment: Once your vehicle is at the repair shop, have a professional mechanic assess the extent of the water pump damage and recommend the necessary repairs or replacements.
Coolant leaks from the water pump are common and a clear sign that it's time to replace the pump. The coolant is stored inside the water pump using a series of gaskets and seals. Once these parts wear out, loosen, or crack, you'll end up with radiator fluid leaking out of the front of your car toward the center.
A water pump should last anywhere between 60,000 and 100,000 miles. A water pump replacement costs between $400 and $800 depending on the vehicle and the difficulty involved. Parts can run from $200 to $400, with labor services similarly priced. These estimates do not include taxes or shop materials, and disposal fees.
DID YOU KNOW? The seal on the water pump has a break in period of about ten minutes of operation. Small seepage is completely normal and very common in a water pump replacement.
In some cases, the water pump can maintain this type of operation for weeks or months, or even longer, or it could fail immediately after by seizing up.
The expected lifespan of a water pump is 60,000 miles to 90,000 miles, but many can last longer than that. Usually, once your car has reached the coveted 100,000 miles, you can plan on the need for a pump replacement soon. Sometimes, this cooling system part will give you signs that it needs to be replaced.
Overheating/Dry Running
Pump seals rely on a thin film of fluid between the seal faces for lubrication and cooling. If the pump runs dry or the seal faces overheating due to insufficient lubrication, the seal can quickly fail, resulting in leakage.
Repairing a water pump typically involves replacing the faulty pump rather than repairing individual components, as water pumps are generally sealed units.
If the gasket is worn, damaged, or leaking, it can be removed and replaced independently of the water pump itself. Replacing the water pump gasket alone is a cost-effective solution if the water pump itself is still in good condition.
An improper seating, damaged seal, or misaligned gasket can mean the water pump is not operating efficiently or, worse, is under undue stress from misalignment. Improper installation will likely also cause immediate leakage from the mounting surface.
One of the best choices for water pump sealant is Xtreme Gasket from Silicone Depot. With a temperature range of up to 650°F, this professional-grade silicone sealant can be used to seal all kinds of mechanical components, including water pumps.
This will appear like a slow drip, which is a good time to change out your car water pump. However, if you need to drive it until pay day, with low mileage and easy driving habit, you could make it a week with a bad water pump.