DEX-COOL coolant

I recently took my 1995 Silverado into the shop to have my cracked radiator replaced. When I got it back the mechanic had put regular green anti-freeze in it and my manual calls for DEX-COOL (red).
Is it ok to leave the regular anti-freeze or do I need to flush it out and put DEX-COOL anti-freeze back in??

Well if it had DEX-COOl before and they added green coolant to it then FLUSH IT NOW!!!!!!!!!!!!!!!!!!!!!!DEX-COOL mixed with green coolant becomes corosive to all seals and will eventually cause anything from thermostat to head gaskets to leak. I have seen it alot. Even transfering a system from green to DEX causes seal probloems. Best bet is to drain as much as possible then fill with water. Run the truck till the stat opens and then shut off and let sit for a bit. Then drain again and repeat for about 3 flushing periods. Then drain and fill with strait DEX-Cool. The amout of water still in the engine will make up the 50/50 mix requirements. Just make sure that the truck wasn't filled with green coolant before. One thing that may save things is if they added Prestone's version of DEX-Cool then your ok because thier coolant is the only one compatible with green coolant. Good luck.

I'm with covvy. Check with the dealers to make sure it isn't Dex, if it isn't I would get that out as soon as possible.

Thanks for the feed-back on the DEX-COOL! I had a feeling that there was a problem when I saw regular anti-freeze. The mechanic said it was fine but I am not very confident in him. For the price of a couple of gallons of DEX I am gonna flush the system and have piece of mind! Thanks guys!