64 C10 overheating problem

[elane352]

Hello!

I have had two occurrences whereby the pressure in my block has blown off the entire lower radiator hose, or the top portion of the lower radiator house. So I want to see how I can avoid that happening in the future. Any insight would be appreciated.

Givens
====
• 64 Chevy C10 pickup
• Formally a 6 cylinder; now has a 350 crate motor in it (installed during May)
• Champion aluminum radiator with shroud and an electric fan – 1,600 CFMs (installed during July)

1st overheating occurrence – blew the entire lower hose off – August time frame
==============================================
• After driving the truck about 40 minutes during a hot summer day, when I parked it and turned off the ignition, the hose blew off.
• After letting it cool down for about 2 hours, got a new hose, put it on, put in antifreeze, and ran the truck (idling it) for about 10 minutes.
• The fan never came on and I noticed that lower radiator hose was not hot.
• That made me think the thermostat was not opening and maybe the spewing antifreeze has messed with the fan wiring since the fan was working beforehand.
• I had the truck towed home.
• I got a new thermostat that opened at about 165 degrees. I also checked the fan wiring and made sure it taped into my painless auxiliary fuse block. Things were working again. The fan was coming on and the lower radiator hose was getting warm.

2nd overheating occurrence – blew the top part of the lower hose off – happened on October 16th.
===============================================
• I was driving the truck back from North Carolina to Maryland (5 hour drive).
• About 45 minutes from home, I hit a stretch of a lot of stop lights. I noticed the temperature gauge needle going up. I pulled over for about 20 minutes to let things cool down.
• Got back on the road and got to the point on the interstate where I was 15 minutes from home. Since I hit standstill traffic, I got off the interstate. Shortly afterwards, the temperature gauge needle went down to 0.
• I immediately pulled over to a parking lot.
• Stopped the truck, turned off the ignition, and opened the hood.
• Then the top portion of the lower radiator hose blew off.
• I had the truck towed home again.

Questions
• Do I need a new thermostat? If so, what is the best one to get?
• What about the temperature gauge going down to zero? Is it toast now? And what caused that? It looks like it is still wired up and the wire does not look to be fried or anything bad like that.
• What about the 1,600 cfm Champion fan? Is that high enough? Should I have gotten a dual fan set up? Has anyone had good/bad experiences with that type of fan?

Again, thanks for your time in reading this.

Sincerely,

Eddie

[71PICKEMUP]

Are you certain the hose clamps were properly tightened? The radiator cap should release before building enough excessive pressure to blow the hose off if the clamps are properly tightened. What kind of radiator cap are you running? Do you have a burp tank? It also sounds like you have an airflow problem. The Champion radiators are good, but the fans that come with them are junk.

[geezer#99]

Take some pics of your motor set up. Something will show us your problem.
Could be simply a plugged rad, cavitating pump that collapses your bottom hose and the clamps can't hold it on.

[The Rocknrod]

Not saying this is all that may be wrong but - The lower hose is a suction hose, you need a lower radiator hose spring inside of it to stop it from collapsing. Also the radiator cap should be a 12 to 15 pound cap in good condition. Your rad cap hose should be set up in a overflow bottle so your not sucking air from it. Similar to this (as an example - not exact):

[vin63]

Could you post the process you went through to purge air from the block and cooling system?

[jtrichard]

I see you have a 350..... long pump or short? ...... V-belt or serpentine ? I seen a V-belt truck that someone had put a serpentine belt pump on and it did about the same things as yours is doing

[shp4man]

Well, I work on Fords mostly, but since the heating issue is at idle/low speed, sounds like that radiator fan isn't working correctly. Plus your radiator cap is no good, or the hose clamps weren't tightened correctly, or both. Does the heater work?
At what temp does the fan come on? Do you have an A/C system that turns it on too?

[vin63]

Originally Posted by jtrichard

I see you have a 350..... long pump or short? ...... V-belt or serpentine ? I seen a V-belt truck that someone had put a serpentine belt pump on and it did about the same things as yours is doing

Many times this is due to certain serpentine drive systems require a newer type of water pump that rotates in the opposite direction of older style water pumps.

[elane352]

Thanks for the responses so far. I am at work still and will not get home tonight until about 11 PM EST. But I will take some pictures when I get home.

Here is what I can respond to now.

• I have a long pump, v belt
• No AC system
• The fan is programmed to come on @ 180 degrees. The thermostat is supposed to open @ 165.
• My heater has never worked. I have not fixed it yet.
• I honestly did not perform a purging process from the block and the cooling system.
• I did have a spring in the lower radiator hose.
• I also installed an overflow cooling tank; but it is on the driver side of the radiator since I did not have much space to install it on the passenger side where the other dilapidated one was at.

Eddie

[forestb]

Make sure the thermostat for the fan is in a good location. I had a thermostat that did not go on until it got to around 220 when it was supposed to come on a 180. I installed in in the rear of the manifold. I moved it to a port in the water neck and now it turns on at 180.
You can check to see if the thermostat for the fan is working or not by unplugging the wire and holding it against raw mettle to ground it. If the fan starts when you do this it means either the thermostat is not working or it is not getting hot enough.

[vin63]

Originally Posted by elane352

Here is what I can respond to now.

• I honestly did not perform a purging process from the block and the cooling system.
• I did have a spring in the lower radiator hose.


Eddie

It sounds like you might have a significant air pocket or several air pockets that may be preventing continuous coolant flow, even creating a complete obstruction. When you are able, look up bleeding or purging air from a vehicle coolant system, and follow that process (sometimes even referred to as "burping" the cooling system) - you may have to do it a few times. I have a feeling that will alleviate your overheating issues if your lower radiator hose is getting blown off.

[jtrichard]

I would check that the water flow is correct sucking from the lower hose/radiator (if you have wrong pump it could be trying to pump the wrong way) and make sure you have the stat in the right direction also ..... and as said above you need a new cap

[elane352]

Thanks again for everything so far.

I do have a 13 lb radiator cap. I will research the burping aspect.

I have attached 3 pictures in this post and 3 in the next post.

Eddie

[elane352]

Here are three more pictures.

[elane352]

Also, one of the pictures shows the lower radiator hose looking a bit crimped.

That is because last night I just put the hose back on, filled the system with water, and got the truck running just to get it back into the garage.

I have always had a lower radiator hose with a spring on it.

Eddie

[geezer#99]

An extra spring in it or the one that might be built into the bottom hose?
What's that shroud that your fan is attached to?
Better pics needed!

[elane352]

Hello,

I am just getting back on my feet after a foot injury. I just finished burping the cooling system this evening after running the truck about 20 minutes.

I got a spill free funnel and tried to follow the directions to the "t." I also got:

* a new SPAL fan that has a cfm value of over 2,100,
* a new 160 degree thermostat, and
* a STANT 13 lbs radiator cap.

I got to the point where the 185 degree fan came on. However the temperature gauge never got passed 150 degrees.

So assuming that the fan is coming on when it is supposed to, it makes me think that if the autometer temperature gauge is sticking firm at around 150, then I have a gauge that is faulty. That gauge will be replaced as soon as I hook up a Dakota digital set up I have.

But the new thermostat appearing not to open up is my concern. If the 185 degree fan is coming on, and I assume that it is coming on @ 185 degrees, and the 160 degree thermostat is not opening up, and the lower radiator hose is not getting warm, am I right in thinking that I have a faulty thermostat?

Let me know please.

Eddie

[andyh1956]

I can help a little w/ every one else's already good advice. If you want to know if you have the correct flow pump do this- attach a hose to the water outlet on the intake manifold where you would feed the heater core. Neck it down to 3/16" or so. With engine at operating temp open the end of this hose & rev engine to about 2000 rpm or so. This hose should pee coolant from it if pump is circulating properly.
Next, you said gauge went to "0" degrees. That means an absence of coolant at the sender, (I don't remember if you have electric or manual gauge) That means you lost enough coolant at that point so as not to have sender submerged in coolant. either a leak, overflow OR the engine is displacing coolant by letting compression into the cooling system.
If the thermostats you are using do not have a piddle valve in them always drill a 1/16" hole in the flange before you install. That lets the air travel up to the upper tank while the engine fills up.
Next, go buy yourself a laser thermometer so you can tell for sure what temps the engine components really are.
But from your description of events it sounds like an airflow problem across the core. Maybe your new fan will help solve the problem! Good luck!