C7 coolant flush advice
Thread Starter
Pro
Joined: Oct 2009
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From: Chaska Minnesota
C7 coolant flush advice
I changed my coolant in my C5 a couple of years ago as suggested in the owner's manual. I believe under normal driving it is 5 years. I have the instructions for the C5 coolant change but haven't been able to locate something on the C7. Is it the same procedure with the C7 as the C5? If it matters I have the M7 with Z51. Thanks.
Team Owner
Joined: Jan 2007
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From: cookeville tennessee
ttt
I did my c7 the same as the c5 just make sure no air in the system. I did run the car up to temp with the A/C on then pulled the cap off make sure the stuff is moving thur the system with car running, fill & top it off put the cap back on & done. But I did put in a 160 & LMR neck & blew the system out & put back in 100% EVANS waterless I got 3 gals & had some over.. Robert
Tech Contributor
Joined: Oct 1999
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From: Charlotte, NC (formerly Endicott, NY)
Easiest way to get to the right mix is drain and refill cooling system with Clear Drinkable Water and run engine after each refill until thermostat is open for a few minutes, then turn engine off and drain. Repeat until the drained fluid is clear. Once drained fluid is clear add how many quarts of Dexcool are required to provide a 40% mixture and top off the cooling system with clean drinkable water. Cooling system capacity with the secondary radiator for the M7 cars is 12.7 quarts and 11.8 quarts for the A8 cars. So if you have an M7 with the secondary radiator (2015/2016 with secondary radiator added or 2017-2019 M7) you need to put 5 quarts and 3 ozs of Dex in the system. If you have the A8 then you need to put 4 quarts and 23 ozs in the cooling system before topping off with water.
Bill
Last edited by Bill Dearborn; Jan 15, 2020 at 01:49 AM.
Thread Starter
Pro
Joined: Oct 2009
Posts: 579
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From: Chaska Minnesota
Thanks for the detailed instructions. My owner's manual does recommend 50% Dexcool and 50% drinkable water if ambient temps are below -18 F/-28C. Being from MN where the temps can get south of freezing, I think 50/50 is right for me. When we left for The Villages last February the Silverado temp was at -27 air temp. The wife got in the truck and said, "get us the Hell out of here." Best month long vacation we ever had. Love Florida.
