I know this will probably bore some people, but I would like to double check the type of coolant to add to the surge tank in an S60. I could not find anything on it in my manual. The owners manual on my 01 says to go see the dealer. It also says you "shouldn't need to change the coolant", which implies it is some kind of super special stuff. The remaining coolant in the tank indeed looks green, like regular Prestone. Can I add Prestone?

 

Yes you can that will be fine.

 

So is it the same stuff is what I am trying to find out. If so, it means two things:1) other manufacturers recommend unneeded coolant changes,and 2) Volvo wants you to go to the dealer to buy the same common stuff you can buy in the stores.

 

It should be the exact same stuff. Most dealers reccomend that you change every 30K.
I agree with that as well.

Most Dealers usually just use Prestone or something like that.

 

I have heard a lot of warnings concerning mixing coolants (I have two cars now with coolant issues). Maybe for a flush and fill Prestone would be good. As for mixing, Volvo says:
Radiators from the field have been analyzed at Volvo's internal laboratories. The analysis indicated corrosion in the internal gearbox fluid cooler. This early failure may have occurred if the coolant was not of the correct mixture ratio (ie. 50% glycol, 50% water), which is the optimal ratio for the cooling system. This mixture ratio must be followed strictly to meet all requirements of the cooling system in order to optimize the freezing point, corrosion durability, boiling point and lubrication. When filling and topping up, use only Volvo ready-mixed coolant. Volvo's guarantee does not apply if the coolant is contaminated with other mixtures or non-genuine coolant of incompatible properties is used in your Volvo car.

(ref: http://www.volvocars.com/sg/salesandservices/maintenance/volvoserviceoffers/Pages/VolvoCoolant.aspx)

 

Tell the Dealers that they don't even follow that.
The last Dealer I worked at they used Pyrol coolant.

 

I was reading the label on Prestone's Long Life antifreeze: they were very clear that it can be blended with any coolant and used in any car. I think I'll use it to top off my surge tank.