proper way to replace coolant
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
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Originally Posted by SJW
I'm always impressed when somebody comes up with a clever idea that allows a "smarter, not harder" approach to a job.
But, I do wonder how much coolant remains in the lower reaches of the block's water jackets using the shop-vac blow-it-out method. Have you tried this, and then yanked the knock sensors to see how thoroughly the block was purged?
I like the idea, but I can't help but suspect that a significant amount of coolant is left behind...
Be well,
SJW
But, I do wonder how much coolant remains in the lower reaches of the block's water jackets using the shop-vac blow-it-out method. Have you tried this, and then yanked the knock sensors to see how thoroughly the block was purged?
I like the idea, but I can't help but suspect that a significant amount of coolant is left behind...
Be well,
SJW
By doing this, I am convinced any amounts of green coolant remaining in the system are minimal at best.
Le Mans Master
Joined: May 2005
Posts: 7,354
Likes: 2,279
From: Central Maryland
Originally Posted by onedef92
SJW, all I can tell you is that I repeat the procedure until nothing but clear water comes out, no green coolant at all.
By doing this, I am convinced any amounts of green coolant remaining in the system are minimal at best.
By doing this, I am convinced any amounts of green coolant remaining in the system are minimal at best.
Thanks for the clarification.
Be well,
SJW
Burning Brakes
Joined: Aug 2005
Posts: 772
Likes: 6
From: Huntsville AL
W/ this proceedure - you are leaving a fair amount of water in the block (pure water). Lets assume for a minute that your system is a 12 quart system (not sure on the LT1).
You have trapped in the block about 6 quarts of water that you cannot get out.
You now install a 50/50 mix of 6 quarts of antifreeze ( that is 3 quarts of antifreeze and 3 quarts of water - that is all you can pour in).
You now have a total of a 25/75 mix of antifreeze to water.
My procedure on all cars is:
1. Disconnect top and bottom radiator hose.
2. Disconnect heater hoses.
3. Remove block drain / knock sensor / whatever will allow you to drain the block if so equiped.
4. Flush entire system w/ water to include heater core, block, radiator, waterpump, etc.
5. Take compressed air (at low pressure) and force any water you can out of the heater core and hoses and block.
6. Reconnect everything and close the drain plug.
7. Check owners manual for total capacity of coolant system.
8. Install 1/2 amount of total capacity of pure antifreeze (remember you never get all the water out).
9. Finish filling w/ water while running the engine and leaving any bleeder screws open until you start to get coolant out.
This ensures you have a true 50/50 mix in the end.
On my 88 - I got 8 quarts back in the system after doing this which means the rest was pure water left in the block.
You have trapped in the block about 6 quarts of water that you cannot get out.
You now install a 50/50 mix of 6 quarts of antifreeze ( that is 3 quarts of antifreeze and 3 quarts of water - that is all you can pour in).
You now have a total of a 25/75 mix of antifreeze to water.
My procedure on all cars is:
1. Disconnect top and bottom radiator hose.
2. Disconnect heater hoses.
3. Remove block drain / knock sensor / whatever will allow you to drain the block if so equiped.
4. Flush entire system w/ water to include heater core, block, radiator, waterpump, etc.
5. Take compressed air (at low pressure) and force any water you can out of the heater core and hoses and block.
6. Reconnect everything and close the drain plug.
7. Check owners manual for total capacity of coolant system.
8. Install 1/2 amount of total capacity of pure antifreeze (remember you never get all the water out).
9. Finish filling w/ water while running the engine and leaving any bleeder screws open until you start to get coolant out.
This ensures you have a true 50/50 mix in the end.
On my 88 - I got 8 quarts back in the system after doing this which means the rest was pure water left in the block.
Last edited by thomastl; Feb 14, 2006 at 08:27 PM.
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
Originally Posted by SJW
I'm always impressed when somebody comes up with a clever idea that allows a "smarter, not harder" approach to a job.
But, I do wonder how much coolant remains in the lower reaches of the block's water jackets using the shop-vac blow-it-out method. Have you tried this, and then yanked the knock sensors to see how thoroughly the block was purged?
I like the idea, but I can't help but suspect that a significant amount of coolant is left behind...
Be well,
SJW
But, I do wonder how much coolant remains in the lower reaches of the block's water jackets using the shop-vac blow-it-out method. Have you tried this, and then yanked the knock sensors to see how thoroughly the block was purged?
I like the idea, but I can't help but suspect that a significant amount of coolant is left behind...
Be well,
SJW
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Originally Posted by thomastl
W/ this proceedure - you are leaving a fair amount of water in the block (pure water). Lets assume for a minute that your system is a 12 quart system (not sure on the LT1).
You have trapped in the block about 6 quarts of water that you cannot get out.
You now install a 50/50 mix of 6 quarts of antifreeze ( that is 3 quarts of antifreeze and 3 quarts of water - that is all you can pour in).
You now have a total of a 25/75 mix of antifreeze to water.
My procedure on all cars is:
1. Disconnect top and bottom radiator hose.
2. Disconnect heater hoses.
3. Remove block drain / knock sensor / whatever will allow you to drain the block if so equiped.
4. Flush entire system w/ water to include heater core, block, radiator, waterpump, etc.
5. Take compressed air (at low pressure) and force any water you can out of the heater core and hoses and block.
6. Reconnect everything and close the drain plug.
7. Check owners manual for total capacity of coolant system.
8. Install 1/2 amount of total capacity of pure antifreeze (remember you never get all the water out).
9. Finish filling w/ water while running the engine and leaving any bleeder screws open until you start to get coolant out.
This ensures you have a true 50/50 mix in the end.
On my 88 - I got 8 quarts back in the system after doing this which means the rest was pure water left in the block.
You have trapped in the block about 6 quarts of water that you cannot get out.
You now install a 50/50 mix of 6 quarts of antifreeze ( that is 3 quarts of antifreeze and 3 quarts of water - that is all you can pour in).
You now have a total of a 25/75 mix of antifreeze to water.
My procedure on all cars is:
1. Disconnect top and bottom radiator hose.
2. Disconnect heater hoses.
3. Remove block drain / knock sensor / whatever will allow you to drain the block if so equiped.
4. Flush entire system w/ water to include heater core, block, radiator, waterpump, etc.
5. Take compressed air (at low pressure) and force any water you can out of the heater core and hoses and block.
6. Reconnect everything and close the drain plug.
7. Check owners manual for total capacity of coolant system.
8. Install 1/2 amount of total capacity of pure antifreeze (remember you never get all the water out).
9. Finish filling w/ water while running the engine and leaving any bleeder screws open until you start to get coolant out.
This ensures you have a true 50/50 mix in the end.
On my 88 - I got 8 quarts back in the system after doing this which means the rest was pure water left in the block.
I've never had a problem with the coolant systems of any of the vehicles I've owned by using my method and I've done this to all my cars since 1990. I change the coolant according to the owner's manual reccomendations.
