Hi all,

Working on engine cooling system and have a couple of questions. First off, Drained radiator, saw lots of scale/mineral deposits on ends of where coolant circulates through radiator. Did the descaling but not too satisfied with results. Still some scale/mineral deposits but the flow through the "tubes" from what I can see looks ok. Will probably do it again.

Changed Thermo 180, upper n lower hoses. Temp gauge reads proper, no water pump issues. Upper, lower and heater hoses are hot.

So my questions are; 

Should I be able to squeeze the upper hose with minimal pressure. (3 fingers)? Can't squeeze lower due to reinforcement inside it.

How do I tell if the fan clutch is bad?

I am assuming it is the object on the front of the fan. With car off, hot or cold, when I spin the fan by hand in either direction it only rotates a little. Bladet 12:00 position. Spin fan and it only rotates to the next bladeor maybe half way to the following blade. Is this ok or should it spin freely?

Thanks for any advice on this.

Sounds like your fan clutch is OK.  Try some of that Prestone radiator flush.  Then flush with clear water.  I always flush once with distilled water, drain, and then go back with the proper 50/50 green stuff and distilled water.  I have a DeWitts aluminum radiator and that is what Tom DeWitt told me to do.

Having said that, on a 97+ degree day here in N. Tejas, sitting at a red light my temp will go to 220 or so.  Once I get going it comes back down.  Only thing that would help me is electric fans instead of the thermostatic fan.

Thanks F4Gary,

Any thoughts on the upper Radiator hose?

Kenny78

Not sure.

Fan clutch will have hard resistance when cold, then loosen up as it gets warmer. Sounds like yours is working properly. With the engine at operating temp, the upper(and lower) hoses will be under pressure...it should be hard to mash the hoses with your fingers. Think of the hose as a tire...with no air(pressure), the tire is wobbly/flexible. With air in it, it becomes firm. 

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

My experience with the thermostatically controlled fans is that when cold and the engine is not running, there is some resistance to turning them. After the engine is started and the fan is spinning, it will be freewheeling after a little bit as the clutch disengages until the air coming through the radiator starts to warm up. After the fan clutch engages, you can usually tell by the increase in wind noise as it pulls the air through the radiator.

If you have deposits on the ends of the radiator tubes, then I would recommend you take it to a radiator shop and have it rodded out. I thought the deposits on the end of the tubes were caused by minerals but the radiator shop told me that it was what they called solder bloom.

1973 L-82 4 spd

To all who reads this.I just had my radiator flushed and used “EVANS” product for the re-fill.It’s a higher temp fluid and my 78 Pace Car seems to like it here in the Florida heat.I’ll find out if it really works as the summer heats up. 

I’ll keep updating as my Pace Car only has 38K original miles however Ive changed damn near every piece of rubber and have had the engine completely gone over by “VetteWorks” in St.Petersburg.She’s running great again since she has been in storage for over 8 years.Ive owned it for almost 2 years now.

Im always interested in the conversations although I didn’t follow as close as I should to the C3 registry.

 Thanks to all,Kevin Hunsicker (Clearwater,Fl)

Something else to add, would be a bottle of "Water Wetter".  It is a waterpump lubricator. 

Click on image for full view

Thanks to all the information. I appreciate it.

Kenny78

It also lowers the surface tension of the coolant so it "clings" better to the coolant passage walls.

Thank you as I will take all the insite from all.!

stay safe and God bless to all this summer season.”Show well”! 

 On my 72, I had the original 3 row core replaced with a 4 row. The fan clutch works properly. I have a 180 thermostat. I'm in Southern California and it gets blazing hot here in the summer . My temp gauge barely gets to the first mark. Thing runs stone cold.. And I did this back in 2002... Make sure you have the hood seals and the shroud. The shroud in itself makes a huge difference... Ask me how I know... LOL

    Reid

www.wildbunchcarclub.com

If your engine is not heating up properly then your thermostat is not working. It can just be stuck open a little bit and the engine will not heat up properly.

1973 L-82 4 spd