Radiator

[gotmud]

Truck seems to overheat and leak antifreeze onto the intake.
I think I need to:
replace the radiator cap - what pressure should I use?
change the thermostat - any suggestikons on the temp? 170/190/etc
should hoses need replacing?

Its really tough setting in traffic in Atlanta and get a whiff of smoking antifreeze...ugh

[Stocker]

Well.... if it's leaking antifreeze, find the leak - then fix it. Check thermostat housing and water pump for leaks while you're looking. I'd suggest a 190* thermostat (180* if you don't need a good heater).

If hoses are soft & mushy or hard as a rock, replace them - radiator and heater hoses.

16# rad. cap will work just fine.

Other than that, what condition is the radiator in, and is anything (dirt, bugs, etc) blocking airflow through it? What kind of fan do you have? How old is the antifeeze, and what percentage?

[OhioDan]

I was finding antifreeze on the intake also. Done some checking, and found it was the o-ring on the fancy "Chrome" thermostat housing. After wrestling with it a time or two, I threw away the chrome leak and got a steel housing and new gasket. Put it on, refilled the coolant, pressure tested the system. Hot da#n, no leak. Hope this helps?

[VetteVet]

Question: Do you have a fan shroud on the radiator. The previous owner of my truck didn't have one on and it would overheat at slow cruising speeds. He used to do the parade thing a lot. We got a fan shroud for it and that fixed the problem. Whatever you do don't run without a thermostat. It will circulate the water so fast that the fan and radiator won't cool it and soon it will overheat and boil out when you're in slow traffic. Believe me I know.. Run the 180 thermostat. The radiator cap is 7 to 9 PSI on the older sustems and 15 on the newer fully enclosed systems IIRC. Do you have an overflow line for the coolant if it overheats and boils over. Ohiodan and stocker both have some good suggestions to follow and doing a search for other threads will give you a lot of answers too.My daughter lives in Marietta so I know about Atlanta traffic. HTH.

VetteVet

[gotmud]

I have the chrome o ring thermostat housing. That may be the problem so Ill check tomorrow. I dont have an overflow installed but I have purchased one. The radiator appears to be in good shape but the cap is old and I thoguth it says 14lbs.
When I put the overflow on should I go to a lesser pressure cap?
I do have a fan shield....makes me nervious to not have one thinking of a fan blade going flying. The fan is the stock fan.
Hope this helps describe my condition...
Thanks for the input!

[Stocker]

When you add an overflow tank (great thing to have, btw), you are creating a sealed system. 14# to 16# should be fine, but you need a cap designed for a sealed system. The old type won't allow coolant flow from the tank back into the radiator as things cool off.

A fan shroud is to direct airflow through the radiator instead of around it, resulting in improved cooling. Doubtful it would do too much to contain a broken fan, though it couldn't hurt.

Stock fans may be fixed-blade (not so good) or clutch fan (much much better).

[Longhorn Man]

If the rad is old at all, stay with the lower pressures ont he cap. They were not designed for the 14/15 psi caps, and you are just stressing the tanks. They will blow off...trust me on that.
In all reality, there should be no reason to have a cap like that on there. You only need the PSI to increase the boiling point. Hopwever, if there is no boiling problem, then there is no reason for it.
The O-ring T-stats aren't as bad as everyone seems to think...it is actually the alluminum intake that causes the problem. The 2 dissimilar metals and antifreeze causes electrolisis after a while. The stock Tstat housing will do the same thing. Metal is metal. The o-ring does tend to wear and leak, but that's only after remove and install a million times.
Check your hoses, drain your coolant, get some of that flush stuff....supposed to help clean your rad out... pour it in, fill up with water, and drive a few days. I doubt you have to worry about freezing in hotlanta. Then drain it, fill again with water...warm it up and drain again.
Fill with new coolant (mixed...straight coolant doesn't cool very well, and freezes at 9 degrees (F) ABOVE zero) and install a new thermostat. Personally I like the 160 ones, but I get flamed for advising that...I've seen plenty of dynos say it helps, and it keeps the oil temp down which helps heep it from breaking down and crystalizing (sludge) and is easier on the cooling system. A 180 t stat is a good comprimise though. I'd replace the cap with nothing higher than 12 psi, and make sure it is for a sealed system so you can use your puke tank you got.
if there is still overheating problems, then your rad or your water pump is probably bad.

[mr402]

One more thing! Don't use the red Dexron coolent. Stuff turns acid pretty quickly.

[gotmud]

Im on it today! Thanks for everyone's input.
I picked up a 64c10 yesterday in Tenn. Will be trailering it back next Saturday. I hope to find the same help in the 60-66 board as there is here!

Thanks again!

[Stocker]

Originally Posted by Longhorn Man

If the rad is old at all, stay with the lower pressures ont he cap. They were not designed for the 14/15 psi caps, and you are just stressing the tanks. They will blow off...trust me on that.

Andy, I'll bow to your expertise on that. My 15-16# advice was based on using that (local NAPA recommendation) on my truck, and 33 years on the OEM radiator...

[Tx Firefighter]

Remember, the only reason for the pressure radiator cap is to keep the water from boiling. A 180 temperature thermostat shouldn't allow the water to boil anyway, so it's a moot point. If your radiator is old or shaky condition, a lower pressure cap would be a good idea.

[Longhorn Man]

Stocker, I'll meet you 1/2 way...
I just looked it up in my 70 owner's manual, it says 13 - 15 pound cap.
I will still say however, if you have an old rad...like original or over 10 years old, and original style, then stick with the lower pressures.

[Longhorn Man]

Originally Posted by Tx Firefighter

...so it's a moot point...

Tx...you just made me cough up my mountain dew from laughing so hard!.
I have only heard one person use this term...and it was misused too. Joey in Friends...he was calling it a MOO point. Everyone looked at him all confused and he said, You know...Mooo...cow moo...it doesn't matter....moo point.
LMFAO!

[Tx Firefighter]

Moot point, from the dictionary:

...a moot point, however debatable, is one that has no practical value...

It's a good thing I did say "Moot" and not "moo" point. You'd have coughed up milk instead of Mountain Dew.

[Longhorn Man]

LOL, milk is a PITA to clean off the moniter.

I just find it amusing...no one uses the term, and the way that joey said it has stuck in my head.

[Stocker]

Originally Posted by Tx Firefighter

it's a moot point.

I love this - my supervisor at work uses this phrase occasionally, but he always says MUTE point!