hi im posting this for my brother (who has a 740)...please feel free to get specific as i have a 940 so i kinda 'get' the issues and any references...

his 740 has the b230E engine (and i have a suspision the rare heron head (but im still waiting for the casting numbers from him to confirm that!) wiht 150k on it

he has a continual problem with weeping from top seal of the water pump (the seal to the head)...

he loses about 1 cup of water a week (say every 400 miles)

the leak appears to only happen when the car is cold...stone cold..

it has been back to an independant volvo specialist 5 times, had 5 new seals and 2 pumps (i believe the pumps are not OEM but pattern)

the shop is now saying that he has severe corrosion on the head and thats why they cant get a seal, they have even tried siliconing the seal in etc...

the car has had a full dealer service history apart from 20000 miles and 2 years when my brother got it and the coolant was thick, blue and goopy (i.e. full of anti freeze)....

the shop is saying 2 choices...

1) pull head, skim head, replace
2) new engine (they just happen to have one....)

another solution that has been put forward (by someone else) is to try a radiator sealent...

anyone got any experience/ideas/knowledge...if it IS the heron head does that needa different seal/pump than standard???...I know im fishing here...but replacing an engine for the sake of a weeping water pump seems OTT