Loss of water , a mystery

[guyzza75]

Hi..can anyone assist? My 2 0 tdi had a water pump go and therefore took to a garage and had a new water pump and timing belt fitted along with all the pulleys etc.. had the car back and runs lovely, however I am now losing a serious amount of water..filling up after every trip. I have checked all the pipes and placed a new expansion tank cap but cannot see any leaking and I can leave standing overnight and on undoing the cap it's still pressurised! It's a head scratcher.. no water in oil no bubbles in expansion tank ,no leaks on matrix radiator thermostat is sealed ....HELP

 

[csaby1973]

Hi,you need to make pressure in the cooling system with an cooler system leaking tester

Inviato dal mio SM-G935F utilizzando Tapatalk

 

[norad97]

I had this happen to me on my B5, losing coolant, checked all pipes and joints found nothing.
Got my local mechanic pressure test the system, looking at all joints and pipes, then found a pin hole in the bottom of the radiator,
it only leaked under pressure, get it tested.
,

 

[NHN]

As above, pressure test.

 

[antwan64og]

The drain tap mysteriously worked itself loose after the last time The engine was refitted.
Took me a good while of head scratching to pin point it since it only leaked randomly

 

[norad97]

At least an easy fix then.