How do you change the coolant?

**Fast_Z28** · 10-09-2008, 01:55 PM

How do you change the coolant on a LT1? And where do I bleed the system and what is the process fior that? I will do a flush also. For that, I think you pour the flush bottle in the radator and add water. Should I bleed it when I flush it?

**Spikito** · 10-09-2008, 02:24 PM

Yeah ive been thinking about doing this but i also have no freakin clue

I almost want to say that if its not running hot dont worry about it, but i wont, im sure its good to clean it out once in awhile

**konigandy6** · 10-09-2008, 02:37 PM

Your best bet is to take it to a mechanic and have a coolant flush done. That way they can pressurize the system and get all the old coolant out and put the new stuff in. Otherwise you are just scratching the surface of the amount of coolant running around in your engine. Plus, with the flush, it can get out any crystalized coolant that has settled at the bottom of your radiator. Just to give you an idea, my dealer charges $98 for a coolant flush, though I have seen them as high as $150. Obviously it is up to you how you want to tackle this situation, but IMO, I would let someone flush it for me with a flushing machine.

**346ci** · 10-11-2008, 04:20 PM

I'm not sure how the LT1 is set up, but on my LS1 I pulled the drain plug on the radiator and the freeze plug out of the block. Then I took a hose hooked up to hot water and flushed water through the radiator cap and upper radiator hose for 5 minutes or so.
I do not recommend a coolant flush offered at dealerships or lube shops, in my opinion they are a waste of money. The flush machines tend to break loose any gunk in your cooling system and deposit it in the bottom of the radiator. Since a coolant flush is done from above the radiator it doesn't have the capability to "suck" the deposits in the bottom of your radiator out.
I know this contradicts everything koniandy6 just said, I'm just speaking from my experiences.

**konigandy6** · 10-11-2008, 07:09 PM

Originally Posted by 346ci

I'm not sure how the LT1 is set up, but on my LS1 I pulled the drain plug on the radiator and the freeze plug out of the block. Then I took a hose hooked up to hot water and flushed water through the radiator cap and upper radiator hose for 5 minutes or so.
I do not recommend a coolant flush offered at dealerships or lube shops, in my opinion they are a waste of money. The flush machines tend to break loose any gunk in your cooling system and deposit it in the bottom of the radiator. Since a coolant flush is done from above the radiator it doesn't have the capability to "suck" the deposits in the bottom of your radiator out.
I know this contradicts everything koniandy6 just said, I'm just speaking from my experiences.

In most cases the deposits you speak of is actually crystallized coolant or aluminum sulfate. If that is the case, the coolant was flushed out far to late. Most places after flushing the coolant system pop the plug on the bottom of the radiator anyway. It all boils down to personal preference anyway, and what you think is best for your car. My experiences lead me to stick with the flush system.