Adding Coolant technique??
Thread Starter
Pro
Joined: Oct 2001
Posts: 554
Likes: 1
From: CA
Adding Coolant technique??
My uncle told me that when I flush and refill, I should refill with the front end raised. This will prevent air from being trapped in the passages of the block. He said this "trick" worked on his Jeep and it solved his running hot problem. Any opinions on "trapping air" during the refill?
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Adding Coolant technique?? (gpagaduan)
You can't raise a C4 far enough safely to eliminate air. With the radiator cap loose, start the cold engine and let it idle to the opening temperature of your thermostat, then remove the radiator cap and race the engine with the throttle cable. This will cause the coolant to start flowing and it will lower. Pour coolant into the radiator filler until its up to the neck and replace the radiator cap and then let the engine back down to idle. You may have to do this more than once as air trapped elsewhere in the engine will work to the top of the block.
Burning Brakes
Joined: Jul 2003
Posts: 811
Likes: 0
From: OH
St. Jude Donor '06-'07-'08-'09
Re: Adding Coolant technique?? (jfb)
:iagree:
I've been tinkering with cars for a long time and I've never had one so difficult to refill as a C4. I just replaced my heater core last month after it blew up while I was driving down the highway - (what a mess- 5:30 in the morning, both windows down, steam rolling out, couldn't see thru the windshield - it really sucked.) Anyway - it took me about two weeks of short trips before I finally got all the air out (I think I did anyway!) I'd fill the radiator using the above method - think it was full - only to have the low coolant level light come on a few days later. I think it took me three times to finally get the light to stay off.
Good luck
Dan
I've been tinkering with cars for a long time and I've never had one so difficult to refill as a C4. I just replaced my heater core last month after it blew up while I was driving down the highway - (what a mess- 5:30 in the morning, both windows down, steam rolling out, couldn't see thru the windshield - it really sucked.) Anyway - it took me about two weeks of short trips before I finally got all the air out (I think I did anyway!) I'd fill the radiator using the above method - think it was full - only to have the low coolant level light come on a few days later. I think it took me three times to finally get the light to stay off.
Good luck
Dan
Team Owner
Joined: Mar 2000
Posts: 83,381
Likes: 87
From: Boston, MA
I've had to fill mine 3 times so far since Friday. After about 50 miles of highway I get the Low Coolant light coming on only sometimes when sitting at idle. As soon as I give it any throttle at all it goes away. I'm hoping its just trapped air and not burning coolant. :( No signs of coolant in oil, exhaust, or exhaust gases in coolant system.
Burning Brakes
Joined: Aug 2002
Posts: 926
Likes: 2
From: chandler az
Re: Adding Coolant technique?? (gpagaduan)
I only had to burp mine once. if you remove the thermostat and drill 3 - 1/8in holes around the flat area on the thermostat it will allow air to pass through. It doesn't even have to get hot to get the air out.
Racer
Joined: Jul 2002
Posts: 275
Likes: 13
From: South Bend, Indiana
Re: Adding Coolant technique?? (brookman)
I installed the Prestone flush kit on my '88. Now I bleed the air out at the tap since it is now the highest point and top off the coolant at the same tap. Works every time.
Race Director
Joined: Feb 2003
Posts: 11,671
Likes: 20
From: Lake Wylie SC
Re: Adding Coolant technique?? (jimtreber)
I installed the Prestone flush kit on my '88. Now I bleed the air out at the tap since it is now the highest point and top off the coolant at the same tap. Works every time.
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Drifting
Joined: Jul 2000
Posts: 1,661
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From: Phoenix, Arizona
Re: Adding Coolant technique?? (jfb)
jfb - Your instructions are good. But use something about 1/16" thick to block the throttle open at the set screw and hold it at about 1,600 RPM - leave it running at this fast idle - for about 10 minutes or so it will repeatedly and intermittently "burp" bubbles of air out (the stat is open) - keep adding to the fill neck opening until no more bubbles come out - seal the radiator cap tightly, then remove your spacer and let it return to normal idle. You won't have to repeat the process. Just remember to leave the radiator cap on, because you will have to repeat the process if you open it.
