Visual inspection of tightness (VW Passat B3)

Check coolant hoses for porosity by squeezing and bending them; replace hardened hoses.

The hoses must be pushed onto the connecting pipes all the way.

Check the reliability of the hose clamps.

Check the expansion tank cap sealing gasket for damage.

Warm up the engine and check if coolant is leaking into the coolant pump area.

If coolant leaks from the hole at the bottom of the pump when the engine is hot, then, as a rule, the seal is defective. In this case, the pump as a set must be replaced.

Finding the leak location can be very difficult. In this case, it is recommended to pressure test the cooling system in a workshop (a special device is required). At the same time, you can check the excess pressure valve in the expansion tank cap.

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