Coolant Change Dilemma

I just replaced the coolant in my 380sl with water by draining the radiator several times until the coolant was clear. My question now is how much antifreeze to add, so that it and the water remaining in the
engine and heater will make up the recommended 50-50 mixture.
I understand the system contains about 13 qts. and Tiger just said the radiator holds 8 qts. So, if i drain the water from the radiator, it should leave 5 qts of water in the engine and heater core. Can I then just add 6 qts of antifreeze and 2 quarts of water to make 13 qts?
Any advice on the best way to do this would be appreciated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    Rob, drain your system with the water. Then premix your coolant 50/50 and pour it in. I usually buy two jugs of coolant and your system may well use more than one.... if not, just get an empty container from somewhere.... not your wife's though.... trouble, speaking from experience
cheers, guenter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You can get a antifreeze/coolant gauge that tells you if the ratio is nearly 50/50. You are allowed +/- 10% so don't worry.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Your help on this and many other things are greatly appreciated here, Tiger :-)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

    Am I missing something here..... you measure the specific gravity to mix the antifreeze 50/50?
-cheers, guenter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Yep.... got $100? http://shamrockchicago.com/duoChekTestr.html

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

On my 1990 I start with a complete drain. Mine holds 8 qts per the manual. So I add 1 gal of antifreeze and top it off with water. No measuring.
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
There are two ways to improve what you are doing to flush your cooling system and refresh your coolant.
The best is to locate the drain plug on the engine block and drain all the coolant. Then you just get the specification from your manual for total capacity of the system and add appropriate amounts of water and 100% anti freeze to create the ratio of mix you want. Up to 70% gives benefit for anti freeze and anti boil, but 50% does a better job of heat transfer because water has what physicists refer to as a higher "cooefficient of heat." Water transfers heat better.
The other method is open the drain plug on the radiator and with the motor running, run a hose into the water intake and let water flow through the system until it runs nearly clear. Then you have all water (almost) in the system. Shut off the motor, shut off the water, let it drain. Then, get the capacity specification as in method one. Close the drain plug. Start filling with anti freeze and if your system has an 8 liter capacity, and, for example, if you want 50% solution, add 4 liters of anti freeze and then fill the rest of the way with water. This method works pretty well, but draining the block is more certain and takes less time.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.