Volvo: Water Pump/Timing Belt/Winter Driving Mode, volvo 850 glt, coolant leak

Question
  I have a 1993 Volvo 850 GLT.  There seems to be something wrong with the cooling units.  I am not sure which part but I figured it was the water pump.  What happens is, you take the car out for the day and it seems to be working fine.  But by the time you get home the thing is almost overheating.  Then you look inside the coolant resovior and bu nothing is there.  so we put some water into it and it goes down. so we drive it again after it cools. Then the check engine coolant light comes on.  So we fill the resevoir, but the fluid goes straight down.  It is always out of fluid.  what seems to be our problem?  
   I have another question also.  I'm sure someone has asked you this before.  In the car you can put it into winter mode and the arrow comes on.  Then if the arrow is flashing there is a malfunction somewhere.  this happens to us as well.  The arrow will flash for a bout a week and the car doesn't seem to drive well and out of no where it shuts off and the car is fine.  Then sometimes it comes back on, but recently it has been off for about a month.  Would you be able to tell me what the problem is?
    My last question is would you be able to point me in the right direction in changing the timing belt?
    Thank you,
       James

Answer
Hello James! I would suggest you get the car checked out ASAP. I would not suggest driving it. I would have it towed to the nearest Volvo shop. It would be tough for me to tell you what the problem is. It sounds like you have a major coolant leak. There may also be a fault with the transmission or possibly the gear position sensor. I would not recommend replacing the timing belt yourself. There is no room for error. It is best to tow the car to a VOLVO shop ASAP before any other damage to the engine or transmission occurs.

Jimmy