Installing Dewitts aluminum radiator

[Jeff C.]

What is the best way to purge the cooling system so I will have only distilled water and anti freeze in the system. I am replacing a copper radiator.
Thanks
Jeff

[William B.]

Re: Installing Dewitts aluminum radiator

I'm also installing a DeWitts Direct Fit in my '67 sb in the morning so would be interested in any comments.
Thanks Bill

[Donald H.]

Re: Installing Dewitts aluminum radiator

Since no one else commented I'll give it a go. When I bought my 66 a little over a year ago, and was not sure of the condition of all the fluids, I decided to flush the coolant. I took the drain plugs out of the lower sides of the block, took off the thermostat housing and removed the thermostat, and disconnected the heater hoses from the water pump. I then proceeded to run tap water from a hose through the thermostat opening on the intake and through the heater hose inlet of the water pump. I was also flushing the radiator, so I was running water throught the radiator also. I did this for close to 1/2 hour and continued until I could see not residue or discoloration of the water coming out the block drain holes.

I didn't, but you probably want to run clean water throught the heater core as well. I assumed my heater core leaks as the heater hostes were disconnected at the core and looped back to each other. By my method you end up with trace amounts of tap water in the system. So, if you really want to, you could also flush with distilled water to remove more of the tap water.

I then filled with a 50/50 mix of distilled water and Zerex G-05 antifreeze.

Don

[John F.]

Re: Installing Dewitts aluminum radiator

Agree with Don, but also take an old piece of coat hangar or wire and push up into the lower block holes as water is running out. It loosens up some old crud. After clear water is running, blow air thru the thermostat opening to get the last water out. I used a little plumbers tape on the block plugs when reinstalling. Refill the block thru the thermostat opening with distilled water, install a new thermostat,then button up the top. Add your coolant and then run the motor up to temp to get circulation going. Top off as needed, but don't overfill. Recheck levels the next day.