Cooling System Question

[Blue124]

I've just replaced the radiator in my 1978. The previous radiator was damaged by a local shop (long story) so I bought a replacement from IAP. I've got it back in (new fan switch, new thermostat too) and filled it with coolant and water. I cranked it up and the fluid level never dropped as expected. The temperature continued to rise well above 190 degrees and eventually boiled over. I tried again later by making sure that the expansion tank and radiator was filled, the heater valve was on and the temperature continued to rise with no drop in the level of the coolant and the radiator fan did not come on. Am I missing a step or not done something I should have?

[pope]

My initial thought is that you installed the thermostat incorrectly as this is a common accurance. Can you post a pic of the therm. in place.
Does the lower radiator hose get hot?
If you pull the wires off the fan switch and touch them together, does the fan turn on?

[Blue124]

I checked and the lower hose does NOT get hot although the upper hoses do.

I touched the wires together and the fan does run.

Here's a picture of the thermostat installed.
http://i44.tinypic.com/2wlwxew.jpg

[So Cal Mark]

I think you have the stat installed incorrectly, but it's hard to tell. Usually one leg has a machined look to it, and that goes toward the water pump. Did you bleed the air from the system when you filled it?

[pope]

OK, 2 things. Take the thermostat off all the hoses and hold it in your hand. Blow into each of the 3 outlets. 2 of the outlets will allow air to pass through, but one will be blocked off. The outlet that is blocked off is the end that attaches to the lower radiator hose. Now that you know which is which, take a drill bit that is no bigger than 1/8" and smaller if possible and drill a hole just like in the picture. This allows fluid to remove the airlock that occurs on Spiders frequently.
Good Luck

[Blue124]

I'll pull the thermostat and check it as you've instructed. The shop that damaged the radiator also installed the thermostat so I'm not sure at all that it was done correctly.

Also, I may not have bled the air correctly. Is the hole drilled as noted the best way or is there something I need to do along with drilling the hole?

Thanks Guys!

[pope]

The hole takes care of all the other crazy bleed rituals.
Usually there is an airlock on the lower rad hose that stops the thermostat from registering the correct water temp. and that stops it from opening. This should correct that. Refill it and run it through a cycle with the fan coming on and adding fluid as required. Dont forget to turn the heater on so water cycles through the heater.

[Blue124]

Okay! What a difference. The thermostat was indeed installed incorrectly. I went ahead and drilled the 1/8" hole as instructed and installed it back as instructed. I topped it off and cranked it up. It warmed up much more slowly and immediately I could see that the coolant in the radiator was moving (like it should!). Water bubbles pushed some water out of the radiator at the top so it looked like it was working the air bubbles out. Just below 190 degrees (based on the temp gauge) the thermostat opened and the coolant level dropped but not significantly. I topped it back up and ran it a little longer. There was so much steam from coolant and water on the hot parts that I shut it off so I can let it cool off, rinse off the coolant and let it dry out. I think you guys got it taken care of! Thanks a bunch!

[rlux4]

Good work Blue. Now the only thing I would suggest if you haven't already done it, is add the "T" from a flushing kit in the heater hose that is back by the firewall. Use the highest point on the one going between the firewall and the head. This is the highest point in the cooling system, and it makes it much easier to fill as much as possible.
Ron

[pope]

Blue, I guess that is a new way to steam clean your engine! Oh yah, above photo, courtesy of Ron Luxmore!

[rlux4]

The giveaway was the carpenter pencils holding the stat up/
Ron