Hello All,
My 960 1997 water pump was replayed together with the timing belt at 86K. Now I have 125K on my car. Last week when the temperature dropped to 0 F I saw a coolant on my garage floor. I checked all clips and hoses and everything seemed to be fine. After removing the timing belt cover and I saw a few drops on coolant near the water pump. I didn't do a pressure test yet but my first assumption is a leaking water pump. How likely it is to have a bad water pump only after 39k of use? Or maybe it is something else? Is it possible that water pump wasn't installed properly or maybe 0 F temperature had something to do with it?

Don't be too alarmed until you see it leaking in warmer temperatures. The water pump seal or gaskets can leak in cold weather. It varies on the model and pump design, but cold temperatures always bring out leaks at the water pumps. YOu may not see it leaking much again. Depending on how much leaked in the first place, it may be no cause for alarm at all. Although, if it was a big leak, it could indicate a worse problem.

Chris,

Thanks for your post on this subject. I just had a similar situation with my '96 960. The low coolant sensor light came on ( temps have been in low teens for 10 days) and I was worried that my water pump was shot but seems it's just leaking due to cold weather.

About a week ago I added coolant to Max mark. Now it is between Max and Min. I know that replacing a water pump is costly. Is there any temporary fix for this problem? Maybe I can buy some king of fluid that can stop the leak.

I believe the MAX mark is where the coolant should be when the engine is at full operating temp. Coolant expand as it heats, therefore if you topped it up when the engine was cold, you may have lost coolant just through that expansion.

Keep watching, check daily, and carry a gallon of 50/50 coolant mix on board. My 50/50 is half green Prestone and half steam distilled water.

Another item, I think Chris H. alluded to it, is that the expansion/contraction coefficients of cast iron and aluminum are sufficiently different such that at a lower temperature there can be some relative motion betweent he water pump and the block. Thus a small leak.

Good Luck,

Bob

:>)

Some of my beliefs are a little different from yours.

The 960 will last best using the Volvo coolant both from a corrosion point and wate pump seal view. The silicates in some of the aftermarket coolants are abrasive to the moving seal of the water pump. You should always use the same type of coolant to top off as is in the system.

The block of the 960 is aluminum and as I remember the pump housing is also. What is sensative to cold is the "O" ring used as a seal. (Remember the "O" rings on the shutle booster rockets?)
--
'96 965 with 16' wheels at 112K. Had '85 745 Turbo Diesel for 200K.

My pump has less then 10k and it leaks when cold through the O-ring. Just a bad design in a well designed car.