Coolant flush
Melting Slicks
Joined: Feb 2006
Posts: 2,938
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From: Columbia SC
The FSM for my 96 calls for the knock sensors to be removed for a full flush from the block, but that is a royal PITA. Based on my experiences and from what I have read on this forum the best was is to drain from the radaitor, fill, run up to temp and repeat. (wait for cool down prior to the repeat). If you do this about 3 - 4 times you should have a fairly clear water upon last drain. On your last refill use the proper 50/50 mix.
Team Owner
Joined: Oct 2000
Posts: 96,443
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From: Fort Knox, KY
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Instead of removing the knock sensors, I'd do what Fast Cop suggests, then reverse-thrust a 6.5 hp or higher Shop Vac to blow the coolant through the engine block, heater core and out of the radiator pitcock.
Just unscrew the metal pressure cap and put the hose over the coolant tank refill hole (black plastic tank) on the passenger side of the engine. The forced air will do the rest.
Next, refill with water, then blow it all out again with the Shop Vac until you're satisfied nothing remains in the system.
Then, refill with coolant/water mix, and open the bleed valve screws as outlined in the FSM or owner's manual to burp the system of trapped air pockets.
Just unscrew the metal pressure cap and put the hose over the coolant tank refill hole (black plastic tank) on the passenger side of the engine. The forced air will do the rest.
Next, refill with water, then blow it all out again with the Shop Vac until you're satisfied nothing remains in the system.
Then, refill with coolant/water mix, and open the bleed valve screws as outlined in the FSM or owner's manual to burp the system of trapped air pockets.
Last edited by onedef92; Apr 23, 2007 at 03:07 PM.
Pro
Joined: Jan 2004
Posts: 707
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From: Syracuse Utah
I have an electric water pump and a T fitting in my heater hose. I just hook on garden hose, open rad drain, and turn on water pump to circulate flush throughout the engine (no need to turn on engine with electric).
The bleed valve (if it is like a 94) in on the neck of the upper water pump intake. It's a small brass screw. Make sure you don't leak coolant onto your opti while bleeding; use a big rag to wrap around everything.
The bleed valve (if it is like a 94) in on the neck of the upper water pump intake. It's a small brass screw. Make sure you don't leak coolant onto your opti while bleeding; use a big rag to wrap around everything.
Team Owner
Joined: Oct 2000
Posts: 96,443
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From: Fort Knox, KY
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You want a tight seal in order to ensure the forced air will fill all the water galleys and passageways throughout the engine and coolant system.
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Race Director
Joined: Feb 2003
Posts: 11,671
Likes: 20
From: Lake Wylie SC
Because I do this so infrequently I wanted to really flush the entire system. This is how I do it. I'm into over kill.
https://www.corvetteforum.com/techti...=222&TopicID=2
I, too, have an electric coolant pump and it makes it so easy to fill the system as you don't have to do the ole "burp" procedure.
https://www.corvetteforum.com/techti...=222&TopicID=2
I, too, have an electric coolant pump and it makes it so easy to fill the system as you don't have to do the ole "burp" procedure.
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
I have an electric water pump and a T fitting in my heater hose. I just hook on garden hose, open rad drain, and turn on water pump to circulate flush throughout the engine (no need to turn on engine with electric).
The bleed valve (if it is like a 94) in on the neck of the upper water pump intake. It's a small brass screw. Make sure you don't leak coolant onto your opti while bleeding; use a big rag to wrap around everything.
The bleed valve (if it is like a 94) in on the neck of the upper water pump intake. It's a small brass screw. Make sure you don't leak coolant onto your opti while bleeding; use a big rag to wrap around everything.
Thanks
Team Owner
Joined: Oct 2000
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From: Fort Knox, KY
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Make sure you don't overtighten the brass bleed screw, either. It's easy to deform the head of the screw since brass is a soft material.
Race Director
Joined: Jan 2000
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From: USA. Northern Virginia
Remember to catch all your old coolant and bring it to a local shop or garage to dump it there.
Its nasty stuff and you really don't want that going into the water enviroment
I use two 5 gallon donut buckets I got from my local Dunkin Donuts to catch all my flushing, makes it as easy as pie, all I do is set one under the rad petcock and flush away
plus I don't have all the slick coolant on my garage floor.
The cool thing about the buckets is that they are very sturdy with a snap lid that has an O-ring...no messy fluid sloshes out
Its nasty stuff and you really don't want that going into the water enviroment I use two 5 gallon donut buckets I got from my local Dunkin Donuts to catch all my flushing, makes it as easy as pie, all I do is set one under the rad petcock and flush away
plus I don't have all the slick coolant on my garage floor. The cool thing about the buckets is that they are very sturdy with a snap lid that has an O-ring...no messy fluid sloshes out
