So...here I am again!

When I push some rpms to the newly reborn 350, the lower radiator hose collapses under the vacuum. I know the spring is probably rusted away to nothing and the hose needs replaced...(I havent taken it apart yet)

I was going to get one from Rockauto but I wanted to make sure the replacement had the spring in it, do they all? (yes I already read the article about the spring only being useful in the factory setting, but thought I should ask anyway)

 

It should come with the spring. Do you have a thermostat installed?

 

Yes, thermostat is installed, I can see flow through the radiator, just when I rev the motor, the lower hose collapses.

All lower hoses come with the spring? I thought I read that some manufacturers didn't?

 

Additionally, the second fan never came on, even when I turned on the AC. Ill have to troubleshoot that when I get some more time. Its not going anywhere, unless someone steals it

 

Your system seems to flow good then. The second fan comes on when the A/C compressor head pressure reaches a certain level. It's not just the A/C being on that does it. It also can come on when the cylinder head temp switch commands it, which is at an equally ridiculous temperature.

 

One more thing. You don't really need the second fan. Since my A/C doesn't work right now (leaked down decades ago), I never hear my second fan. I'd be turning the engine off before it ever got hot enough to kick on. This isn't NASCAR so I don't think 245F is a reasonable temperature to turn a fan on.

I switched my thermostat and now will reprogram my ECM to turn the primary fan on at a decent temperature too. I'll probably switch my cylinder head temp switch for a lower temp as well. 200F-210F sounds allot more like the time to turn on the second fan.