We here at CARspec can’t stress enough the importance of following factory repair procedures and using original equipment parts and materials.
The photo above is a prime example: a coolant leak (pink in the photo) from the thermostat housing to water pump connection (at the end of the screwdriver) was caused by improper sealing and/or aftermarket fix-in-place gasket (called FIPG), discovered during a routine maintenance inspection.
During a previous replacement of the owner’s water pump the technician used aftermarket grey-colored FIPG where Toyota calls for the use of its own 1282B black-colored silicone liquid gasket, pictured below:
The result, either due to poor cleaning, coolant residue on the sealing surface, and/or the wrong liquid gasket caused a leak and a risk of overheating. We’re glad we caught it before it caused damage. CARspec always recommends the use of 1282B for water pump, timing cover, and any other cooling system seals.