News Technical Service Bulletins

That Mazda Water Pump Might Be Just Fine

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MAZDA TSB 02.jpg

An accumulation of crystallized coolant requires pump replacement.

Mazda notes that some water pumps are being replaced needlessly on models including 2020 CX-30, 2016-2020 CX-3, 2013-2020 CX-5, 2007-2012 CX-7, 2016-2020 CX-9, 2004-2005 Miata, 2006-2020 MX-5, 2004-2020 Mazda3, 2006-2015 Mazda5 and 2003-2020 Mazda6 vehicles. There is a concern that some water pumps are being replaced that are not faulty due to signs of a very small coolant leak from the bleed hole.

A mechanical seal is used for the water pump. This seal can seal coolant by sliding a mating ring against a seal ring. When the sliding surface temperature of the seal is more than 248 degrees Fahrenheit, a small amount of steam is leaked and bleeds through the bleed hole. After drying, the steam leaves a green coolant deposit near the bleed hole. This is a normal condition.

MAZDA TSB 01.jpgA small amount of green coolant deposit near the bleed hole is normal.


The water pump should only be replaced is there is an accumulation of crystallized coolant near the bleed hole.

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