bad water pump??

[kerry]

I live in the USA but recently purchased a motorhome in the UK. It is based on a 1983 Mercedes 307d chassis. It has a 2.399 litre diesel (om616.9). I picked it up last week and drove it to a storage site until I can use it next summer. As I was driving it to the site, it began leaking coolant at the front of the engine and it would give an occasional screeching sound, particularly at higher rpm's. The leak was definitely right at the front of the block and not from the radiator. The coolant was dripping off just behind the lower pulley. This is the first Mercedes I have owned. On all my other vehicles (except for the Corvair I owned) I would take those symptoms to indicate a failed/failing water pump that needs replacement. Do you agree? If so, can you tell me if replacing the water pump on this engine has any special difficulties involved or is it similar to the replacement of a water pump on a typical US engine?