I just bought a 1999 4x4 Chevy Blazer. A friend of mine checked the radiator fluid and it was brown in color, I was told it could be the original coolant that was never changed or someone put some sort of stop leak in it. Please help.

 

Flush the engine coolant system and refill it.

 

I bought my 2000 used and it all ready had the intake gasket fixed and a new radiator put in. I took the thermostat out drained the coolant and filled with water and put the T-Stat cover back on and ran it. I did this twice to get rid of the Dex cool I put regular coolant back in and its been fine.

 

I have heard that regular coolant can corrode these radiators, but then again I am a first time Blazer owner.

 

I doubt that the coolant in your truck had been changed. If it was it probably had not been done for a looong time. Any cooolant (even DexCool) must be changed out on a regular basis. I say not less than every 3 years and don't believe the misinformation and urban legends about the 'dangers' of DexCool, but let's not turn this into a 'DexCool thread'.

 

Thanks for all the help, any advice is greatly appreciated.