Ok, I did a search and got some info, but looking for a little more help please, I have a '98 4runner 3.4 and need to top of the coolant, should I get Toyota brand coolant from a dealer or is it ok to top off with regular. When I flush out system next I should use toyota brand right? but what about to just top off?

 

Here you go:
The Red Toyota coolant is a low silicant formula unlike the "green" stuff. Silicates turn into acids and eat up your aluminum. the block/heads/water pumps are all alluminum!! So to top it off yes, use toyota coolant or straight water. just make sure that your specific gravity (temperature range) is good for your area. Frozen blocks are not fun!

 

If you use water, make sure it is distilled water.

 

I"m a mechanic for an International dealer and we recently were informed that we had to add (yes add) a silicate solution to the extended life coolant ( the red stuff) because without the silicate the aluminium timing covers on the International engines were being eaten away at the gasket areas. I plan on keeping the extended life coolant in my taco, just somthing else the engineers havent worked out yet (DON't MIX THE RED AND GREEN !!!!!)

 

I've had my 84 Camry for about 12 years and have always drained and refilled with Prestone every year. I have never had any issues. To my knowledge (at least since I have owned it) it has never had the water pump replaced-or really much of anything else for that matter.

I usually recommend stock for most stuff, but I just wanted to throw that in.

Oh yeah, do as Tacomanator said and used distilled water. The tap water contains minerals that cause deposits over time and probably do more harm than anything else.