Coolant Overflowing!!

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jmcgill89

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So, I managed to take my 73 out on a good 15 mile ride today. When I got home, I did some adjustment of the carburetor to lower the idle, and just when I got it all fixed up and turned the car off, I started smelling coolant. Lo and behold, green stuff is pouring out the overflow hose on the radiator. I'd say I lost a good quart or two. It just kept coming out. Finally it stopped and I started cleaning up the mess, and then I noticed that the radiator cap has something to the extent of "align vent with hose" on it. Now, I'm not sure where the vent is but I guess the hose is the radiator overflow hose where I was getting my coolant leaking out.

Is it possible the cap was on "too tight" so as to not let the system vent at all, and building up too much pressure resulting in the overflow?

I'm confused/scared. I hope I didn't screw the car up.

Thanks,

Joe

 
Your Thermostat could be stuck and not letting much water threw...Dout it would have to do with the cap...There not spendy to get one...And does it have a clutch fan? Some times they can go bad and not be turning your fan fast enough...You should be ok sence its winter time...But i would check your thermostat...You can pull it out..And boil it in a pan of water and see if it opens..But there so cheap mite as well get a new one.

 
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Would not the car overheat if the thermostat wasn't working?

I don't know about the clutch fan, but I'll check.

Your Thermostat could be stuck and not letting water threw...Dout it would have to do with the cap...There not spendy to get one...And does it have a clutch fan? Some times they can go bad and not be turning your fan fast enough.

 
Would not the car overheat if the thermostat wasn't working?

I don't know about the clutch fan, but I'll check.

Your Thermostat could be stuck and not letting water threw...Dout it would have to do with the cap...There not spendy to get one...And does it have a clutch fan? Some times they can go bad and not be turning your fan fast enough.
Ohhh yes.. First thing i check if my car overheats when its cold outside and i havent been hard on it....They dont go bad too much..But i replaced one in my mustang in the 15 years i owned it....And on the radiator cap..Usualy people only replace those when there not getting enough pressure...Rubber wears out...they can go bad too...You can replace them both and then move on your trouble shooting.

 
Did you recently add coolant and have you taken it for a ride since. You might of just had to much coolant in the tank and the extra ran out. How was the temp gauge on the car? Was it overheating? That is why an overflow tank is good to have. When the coolant heats up and expands it goes into the tank and when it cools down it sucks coolant back in instead of air.

 
So, to answer a number of the questions:

It does NOT seem to have a fan clutch. I can't turn the fan at all, yet I get some great wind when the car is running.

As for the coolant level, I checked it the other night, but didn't put any in as it was full to the right level, or so I thought. Now, looking at my Ford manual, it may have been a bit high.

Thanks for the info on the cap, so I should align the arrows even if it is not "screwed on" all the way to the stop?

I do not have an overflow tank, nor do I have a temp gauge. I guess I should use my digital thermometer on it when I can. What temp am I gunning for?

Should the big hose that goes from the radiator to the thermostat housing have any pressure in it when the car is running? When it's running, it's really easy to squeeze, when the car is off, I can hear the coolant in the radiator sloshing when I squeeze it.

I'm really not used to these old style radiators, every car I've ever had has had an overflow tank..

How difficult is it to do the thermostat?

Did you recently add coolant and have you taken it for a ride since. You might of just had to much coolant in the tank and the extra ran out. How was the temp gauge on the car? Was it overheating? That is why an overflow tank is good to have. When the coolant heats up and expands it goes into the tank and when it cools down it sucks coolant back in instead of air.

 
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Your Thermostat could be stuck and not letting much water threw...Dout it would have to do with the cap...There not spendy to get one...And does it have a clutch fan? Some times they can go bad and not be turning your fan fast enough...You should be ok sence its winter time...But i would check your thermostat...You can pull it out..And boil it in a pan of water and see if it opens..But there so cheap mite as well get a new one.
I agree, the cheapest ($7.50) and quickest "possible" fix for that problem is changing the thermostat. Since you've done the labor I wouldn't consider putting the old one back even if it's not the issue, it's a good time to replace it before it does fail.

 
So, to answer a number of the questions:

It does NOT seem to have a fan clutch. I can't turn the fan at all, yet I get some great wind when the car is running.

As for the coolant level, I checked it the other night, but didn't put any in as it was full to the right level, or so I thought. Now, looking at my Ford manual, it may have been a bit high.

Thanks for the info on the cap, so I should align the arrows even if it is not "screwed on" all the way to the stop?

I do not have an overflow tank, nor do I have a temp gauge. I guess I should use my digital thermometer on it when I can. What temp am I gunning for?

Should the big hose that goes from the radiator to the thermostat housing have any pressure in it when the car is running? When it's running, it's really easy to squeeze, when the car is off, I can hear the coolant in the radiator sloshing when I squeeze it.

I'm really not used to these old style radiators, every car I've ever had has had an overflow tank..

How difficult is it to do the thermostat?
its easy to do...If you dont have a good radiator hose..Good time to replace it too..... here is a good web page stating what temps it should be runing...Mine runs about 180...up too 190ish on a hot summer day http://www.banzairunnerpantera.com/updates_thermostat.htm And yes.. it will be easy to squeeze...Specialy when its hot!!..not that much pressure in there...Specialy if the thermostat is stuck.

 
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Is the thermostat directly under where the big hose goes to the block?
Yup!! Sure is...Make sure you get what your ford manual says to get."if you got one"..should be a 180 degree thermostat...they will ask you at napa or where ever you get it...And usualy they have the info too on which one the factory calls for.

 
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I'm going to look into that tomorrow. We're due for rain the next two days, so it will be tough to get it out on the street anyway.

I'm going to get it up to operating temp again to see if I get an of this overflow action again. I'm also going to test the temperature when it's good and hot, and make sure it's not overheating

Oh, for a good left side of the cluster, so that I had my idiot lights.

Is the thermostat directly under where the big hose goes to the block?
Yup!! Sure is...Make sure you get what your ford manual says to get."if you got one"..should be a 180 degree thermostat...they will ask you at napa or where ever you get it...And usualy they have the info too on which one the factory calls for.

 
I would try a new radiator cap before doing anything else.

It can be that simple.

It's happened to me before. The cap can look good, but if it's weak, or leaks any pressure at all that makes the boiling point of the coolant much lower. The coolant will heat soak in the block after its shut off, and begin to boil. Result: green garage floor!

 
Unless you really want your car to look 100% original. I would put in an after market temp gauge. The reason I say this is because when the dummy light comes on it is usually to late. You can mount it anywhere you want and even build something to hide it at car shows if you want the car to look concours correct. But having a temp gauge might save your engine someday. They are simple to install and are really cheap.

 
After you restart your engine cold. Carefully touch the top of the top hose going to the engine every minute or so. You'll notice it stays cold until the thermostat opens and then gets hot. (180-195) depending on your thermostat. If it just gradually gets warmer and warmer the thermostat is stuck open. Does your Temp light on the dash come on when you first turn the key to tell you your light is working?

 
No. All my idiot lights save the alternator one (which is hard wired to the alternator) are dead. I have no left side turn signal light and no dash lights on that side. I think the printed circuit is shot. I will try to put in an aftermarket gauge pod for oil pressure and temp.

Should that hose be pressurized? It doesn't seem to have pressure when the car is running.

 
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Until the engine is up to temp it's building pressure. Once at operating temp, the whole system is under pressure this allows the fluid to rise to a higher temerature without flashing to steam. Borrow a thermostat tester that also can has the attatchments to pressurize your engine. DO NOT GO ABOVE THE STATED RADIATOR CAP PRESSURE!!! Let it sit for an hour and see if the system holds the pressure. Then do the same with the cap with that attatchment. Tells you everything you need to know.

 
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