I plan on draining the cooling system and was wondering how much antifreeze mix will be needed to refill?

Thanks

 

Dry is about 11-12 liters, or 3 gallons +/- for the engine cooling on pretty much all of the C7's. Use the GM specific stuff, and the 40/60 mix ratio; don't mix the GM stuff with "regular" antifreeze, not compatible. So if the stuff you get is the concentrate, you'd need x2 one gallon jugs and a couple of jugs of drinking water to mix with. You'll have some left over, so that's OK in case you need to top up later.

 

I did a drain and fill of the radiator only. I drained out about a gallon and a half was all that came out. I filled it will the Prestone antifreeze for GM vehicles.

 

Thanks for the info!

 

Yeah... you never seem to get ALL of the old stuff out. When I did mine it was probably close to 2 gallons, maybe a bit more. But I wanted to have the max on hand since I couldn't be sure how much I'd get out.

 

The Corvette uses a 40/60 Dexcool/Water mixture. The cooling system capacity can be found at the rear of your OM. Here is the latest info from the 2019 OM:

LT1 engine is used in Stingray, Stingray Z51 and GS. LT4 is only used in Z06 and the LT5 is only used in the ZR1.

Here is the same info from the 2018 OM:

If you have a 2019 you can check your RPO list to see if your car has RPO V08. The amount of Dexcool coolant you will need will be 40 percent of the quantities shown above. To get there you will have to drain and refill your cooling system with clean drinkable water several times (running the engine after each subsequent refill to get the thermostat open and move coolant out of the heater core) while watching for the drained fluid to run clear with no color at all. Once you have clear fluid coming out of the drain you will have all of the old Dexcool out of the system with only a couple of quarts of water remaining. Make sure the drain is closed and add the quantity of Dexcool needed to get to 40% (40% of 11.8 quarts is 4.72 quarts of Dexcool which is just a little over a gallon. I would add 4.75 quarts (easier to do) and then top off with clean drinking water until it reaches the base of the reservoir fill neck. Run the engine for two minutes between 2000 and 2500 rpm then allow the engine to idle for a while and top off with another quart of water if necessary. Install the pressure cap and let the engine cool and top off with water if necessary.

Bill

 

 

Any reason you don't want to use a place with a fluid exchange?

 

Chevy dealer said didn't need flush (2019 and 8500 mi). Suggested drain and replace.

 

Isn't the interval 5 years or some mileage, whichever comes first?

 

I would definitely try and go with a vacuum device to refill the system to avoid any trapped air pockets.

I once didn't use the vacuum device and ended up with an air pocket creating a hot spot that blew the head gasket. This car did not require a vacuum device, just like the Corvette, to fill the system and should of, would of, could of, burped out any trapped air pocket. Just my luck it didn't.

So now I always use a vacuum device to fill the radiator just like 95% of all dealership mechanics do.

 

Yes it is. 5 years/150K miles.

 

I wonder why. Makes me think that they either don't have the machine or don't want the job for whatever their reason. Either case, find another dealer would be my thought. Makes me think of 2020 when I went to the dealer who sold CanAm and Polaris. Tried talking me into a Polaris. When I asked to ride both, the truth came out. He had no CanAm machines. So now we know why Polaris was better.

 

My 2014 Z51 was purchased 9 years old with 31K miles. Van Botel said both the coolant and brake fluid were discolored. Records showed they were never purged and refilled. Manual says 50K miles or 5 years, so I had them do the purge and refill prior to a 3K mile trip/rally.

 

What happens if you slightly exceed the 40/60 mix?
I am looking to lower the freeze protection.

 

 

What temperature are you looking for protection from?

 

Thanks for the replies.
Was thinking -20.
40/60 should be sufficient

 

When we did mine a couple of months back, it took right at two gallons of the GM Pre-mix stuff. Here's a little tip that I wish I'd known when I started taking mine down. Get yourself one of those off of Amazon. VERY worth the investment. Here's the next little tip - there's a little pressure relief port on the bottom of the surge tank (replace that while you've got the system down - they get old and brittle after a while.) that you'll need to plug or cap before you start drawing a vacuum on the system. Otherwise, you'll never be able to get it to draw a vacuum. Once it's got a good vacuum on the system and your hoses are collapsed - then you open the valve and draw in the coolant from the jug. It purges all the air out and allows you to completely fill up the system without any air bubbles trapped in the system. I also found that the crazy 5 outlet heater hose had been leaking (you couldn't see it from the top side). That's the hose that runs UNDER the airbox and electrical boxes on the passenger side of the car.

We get up in the mountains and romp some so I dropped in a Granatelli 180 degree thermostat while I was at it. Now, the car runs nice and cool on hot days and really seems to like the cooler thermostat.

 

Here's the thread I was on when we were discussing this topic a while back. Some better information in there and I included a picture of the bottom of that surge tank.
https://www.corvetteforum.com/forums...erheating.html