So, my Cold Case radiator came back from the paint shop today and I will also install a new 180 thermostat. I'm just wondering how much of the approximately 20 quarts of coolant will drain if I just open the radiator drain cock and remove the bottom radiator hose? And, after all the coolant drains, will I be able to remove the thermostat housing without losing any more coolant from the intake manifold? At $17 a gallon I'd rather not have to buy any more than I need to replenish the system when the new radiator and thermostat are in.
About a third; if even that much. With an expensive aluminum radiator (and even a cheap one) I recommend dumping the tank every year. I use cheapo Autozone coolant just because I throw a bunch away every year. When yer all done with this job stick a multimeter lead in the radiator and find out how powerful a battery you've created. Too powerful and yer radiator won't last long.
You don't need to drain the entire radiator, just below the level of the thermostat housing, that's it. You'll lose a little coolant, VERY little, when you break the seal of the housing.
Thanks, Larry. I'll post the results of the install as I know you and others are following how this Cold Case radiator works out. Since I'm also replacing the radiator, I'll lose a bunch of coolant when I remove the bottom radiator hose, so I'll capture and reinstall it when the new radiator is installed. The 50/50 mix of coolant is not more than 6 months old anyway.
The later blocks do not have drain plugs for the block water jackets. My 75-76 block did not. When I did my timing cover, I started by draining the radiator. Then removed the lower hose at the radiator which drained some more. I then jacked the back of the car up as high as I could get it. I then removed the lower long water pump bolts on each side, and that drained more coolant. Then I lowered the back and jacked up the front of the car. When I removed the timing cover, there was NO coolant that dropped into the oil pan, and I could not see any coolant in the 2 holes in the front of the block.
The results are in. I installed the Cold Case radiator (p/n GMA42A) and, other than missing the oil change bucket and dumping a gallon or so of coolant on my garage floor, all went well. So, here's my overall review: Install - Radiator went in using the existing top and bottom rubber insulators. Not perfect but nearly so. The radiator cover fits perfectly and the fan shroud hooks back up with no spacers required like the previous radiator. The transmission cooling lines were nearly perfect. The top one was exact and I did have to bend the bottom one a little to get it to mate up. I decided not to install the 180 thermostat so see what is in there now and also to see what just the radiator replacement did by itself. Performance - Temps with the old radiator were over 180 cruising w/o A/C and about 200 with the A/C on. An increase in speed caused the temp to approach 215. Now, cruise fully warmed up is just over 160 and it doesn't change with the A/C on full blast. Several minutes idling with the A/C on raised temp to about 190 and it comes down fast once cruising speed is reached. The engine apparently has a 160 thermostat in place now. Temps out today were in the high 80s so, I'll do some more testing with 90+ degree temps before I decide to pull the 160 stat in favor of the 180. Truth be told, I enjoy seeing the motor running nice and cool. So, I'm happy with the Cold Case radiator.
