I want to change the antifreeze in my 99 sierra. 103,000 mi on the truck.

Where the he** is the radiator cap on this thing? Is it under that plastic cowling under the hood, if so how do you remove the plastic pins?

Also I think they book recommends using dex-cool extended life AF. I have read some bad things about dex cool, should I use this or some other brand?

It has the orange color coolant in it now.

 

which engine?

 

Engine is a 5.3 L

 

Well, I can only assume the radiator cap is on the top of the radiator just like most other truck's is. It's probably on the left side of the radiator. If you're talking about the radiator drain plug, then it'll be down at the bottom of the radiator on either the right or left side.

Juse use dex-cool. I don't know about you, but I'm not smarter than a GM engine engineer. The orange coolant you have now is dex-cool; put dex cool back into it.

 

Can't see the radiator cap or the radiator for that matter, it is covered with a plastic cowling.
I am not sure how to remove the cowling, as there are plastic rivets that I don't know how to remove without damaging them.
The drain **** is on the right hand side.
Thought someone would have a 1999 sierra and have changed the AF and tell me how to remove the plastic rivets, looks like is takes a special tool.
I am using the dex cool, i picked some up today.

Thanks for your reply

 

Maybe the fan cowling? What does your overflow bottle look like?

Perhaps share a picture.

 

the instructions for 99-06 silverados do not mention a radiator cap, just the plastic surge tank, which uses a tight fitting pressure-cap

 

Your right there is not radiator cap, only the surge tank.

 

Dex-Cool is mainly for cast aluminum. You have cast iron which you can use green. I rid my 2001 5.3 of the orange and went with the green, kept getting gunk from the break down on the bottom of the radiator. Whe filling up, there is a certain way to burp the system.

 

i have the same engine and there is no cap

the plastic cap comes off with a screwdriver just pry it up and they can be just pushed back in.

when i did mine i pulled the bootom hose out and drained it like that and to burb the system i opened the resivior tank and held the truck at 2000 RPM and i got all the air out