Coolant leak on 1.9 tdi

My passat 1.9 tdi is leaking coolant from housing on right hand side of engine from front. Pipe leads from it to expansion tank to radiator. What is this housing called?

heater matrix. There are 2 pipes which go into the housing. Around £10 each here in the uk. Make sure you get the right one. The prolem is the ruer washer in the pipe its corroded.

Chaning the pipe takes around 20 minutes and more if you have thums for fingers.