Radiator over flow question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hogrocket · 10-08-2007, 05:55 PM

I was wandering if these trucks came with a radiator over flow canister and if so, where does it sit. I was noticing when my engine runs water from the radiator overflow tube ends up on the ground. It stops dripping when I shut the engine off. Mine is a 70 3/4 ton 4x4 with a 350 and AC. I don't see anywhere an overflow bottle would mount. Thanks in advance. MM

cdowns · 10-08-2007, 06:02 PM

most didn't come with overflows just used the old school dump on the ground method// i do believe there was a super rare dealer installed optionthat mounted above the fan shroud

Longhorn Man · 10-08-2007, 06:13 PM

no factory offerings, just dealer installed ones.
Your coolant level should be one to two inches below the cap. If it's that low and still pukes, you may have an overheating problem.

ChevLoRay · 10-08-2007, 06:14 PM

Get a canister from a Hot Rod shop. I have one that I am going to attach to the radiator support to capture the overflow. I don't have any issues with overflow at this time, so putting one on my truck is just for my ego.

If you are losing coolant through the overflow, you may have a bad radiator cap. There are cooling system pressure testers that can help pinpoint the sources of coolant leakage, whether it is a hose, a loose clamp or the radiator itself. The radiator caps also deteriorate over time. Check the rubber that fits down into the neck of the radiator. Try to bend it to see if it breaks, or not. Usually, the rubber gets brittle and hard. Bending it will cause it to break. This means you need a new cap. Or, it could just be that the cap isn't the correct one and isn't designed to hold the pressure that your system needs to maintain. Caps are cheap...get a new one if you have any questions about yours. Besides, winter is right around the corner and having a good cooling system is just as important in winter as it is in summer. Low coolant will deprive your heater of any water to keep you warm. Usually, coolant recovery systems use a different cap that will maintain the pressures and let the excess vent to the capture vessel. As the engine cools down, a siphon will be created that will suck the overflow coolant back into the radiator.

70GMCer · 10-08-2007, 06:50 PM

Wasn't there a thread on here sometime back where someone used a windshield washer bottle for the overflow?

ChevLoRay · 10-08-2007, 07:50 PM

Probably....or so my memory stick is saying so....but I'd be a bit leery of using it to capture hot coolant. I'd go with a better sort of vessel than a windshield washer bottle, but that's me.

Sinister · 10-08-2007, 09:05 PM

My '69 has an overflow bottle mounted over the driver side fender well, looks factory/dealer installed. I'll try and get a pic of it...

tcb-1 · 10-08-2007, 09:12 PM

hogrocket,
had the same problem. I posted about two weeks ago wondering what others were using for a "burp" bottle. my 350 burps a little each time it gets really warm.
someone mentioned the windshield washer bottle trick. then some owners have simply order one from Jeg's/Summit.
someone correct me if I'm wrong, but you will need to install a radiator cap that allows the flow to re-enter the radiator after the overflow enters the burp bottle.
good luck. post on your final decision 'cause I'm needing the same advise!

aventur1 · 10-08-2007, 10:47 PM

On my 71, which I'm the 3 owner and I'm guessing this is where they mounted it. I've seen other photos that do not have the bottle and there's a hole in the fender where one would go. Don't know? As you see mines on the passenger fender.

70c10 · 10-08-2007, 10:55 PM

PICKMUP sells a nice kit for our trucks!. I'm planning to run a JAZ bottle mounted to my core support. They run about $20 and they have them in the overflow type and the recovery type.

72BLUZ · 10-08-2007, 11:35 PM

Quote:

Originally Posted by Longhorn Man

no factory offerings, just dealer installed ones.
Your coolant level should be one to two inches below the cap. If it's that low and still pukes, you may have an overheating problem.

IN MY LINE OF WORK, WE FIND THAT IF ITS NOT OVER FULL. THEN THE RADIATOR CAP MAY NOT BE HOLDING PRESSURE, OR IT MAY NOT HAVE THE RIGHT POUND CAP FOR YOUR SYSTEM.
I HAVE NEVER HAD A PROBLEM WITH COOLANT PUSHING FROM MINE. I REPLACE THE CAP ONCE A YEAR ON EVERY VEHICAL I HAVE. THE AFTER MARKET COOLANT RESERVOIRS ARE NICE, MADE OF POLISHED ALUMINUM. I HAVE SEEN THEM MOUNTED ON THE DRIVER SIDE OF THE RADIATOR

hogrocket · 10-09-2007, 01:49 AM

I think mine is just "burping" as it does not run hot (around 190) and not that much coming out. I just don't like the dripping. I think I will go to the pick-a- part and find an overflow bottle and mount it on the lower rt side. I'll change the cap also. Thanks for all the advice. MM

70c10 · 10-09-2007, 07:11 AM

hogrocket- if you go to the junkyard, I think there was a post a long time ago about a 1981 Malibu bottle working good on our trucks.

Longhorn Man · 10-09-2007, 05:23 PM

72bluz, you are absolutly correct. Har hardly ever see that issue at the shop i work at, however, we don't work on stuff this old either.
good call

BCOWANWHEELS · 10-09-2007, 05:33 PM

I,VE got some new caps made for overflow bottle use. there genuine GM and will fit a washer bottle perfect. there obsoliete now from gm. there 16.00 each delivered for a cap.

70GMCer · 10-09-2007, 06:24 PM

Quote:

Originally Posted by BCOWANWHEELS

I,VE got some new caps made for overflow bottle use. there genuine GM and will fit a washer bottle perfect. there obsoliete now from gm. there 16.00 each delivered for a cap.

Pics??

BCOWANWHEELS · 10-09-2007, 09:12 PM

here it is... all i have left are the clear ones now. there identicle except for color.
bob

**PICKMUP** · 10-09-2007, 11:16 PM

Sorry, I don't have any more for sale...caps are all gone!
They really look good in a clean engine compartment, if you don't want the "bling" of the polished aluminum.
They match the WS bottle on the other side, bracket & bottle, so they look stock...like they belong there. Run a 3/8" hose to the radiator overflow tube. Plug the extra hose nipple and drill a small vent hole on top of the plastic cap. You don't need a second hose.
Although there may be some kind of special recirculation radiator caps available, (that we don't seem to be able to accurately identify), I have found the stock cap seems to work fine. The fluid in the bottle goes up hot and back down into the rad when cool.
The GM part is #340194. There are still a few of these left in local dealers. Some are black/some are clear.

10-08-2007, 05:55 PM	#1
hogrocket Junior Member Join Date: Apr 2006 Location: San Diego Posts: 100	Radiator over flow question I was wandering if these trucks came with a radiator over flow canister and if so, where does it sit. I was noticing when my engine runs water from the radiator overflow tube ends up on the ground. It stops dripping when I shut the engine off. Mine is a 70 3/4 ton 4x4 with a 350 and AC. I don't see anywhere an overflow bottle would mount. Thanks in advance. MM

10-08-2007, 06:02 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Radiator over flow question most didn't come with overflows just used the old school dump on the ground method// i do believe there was a super rare dealer installed optionthat mounted above the fan shroud __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

10-08-2007, 06:14 PM	#4
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Radiator over flow question Get a canister from a Hot Rod shop. I have one that I am going to attach to the radiator support to capture the overflow. I don't have any issues with overflow at this time, so putting one on my truck is just for my ego. If you are losing coolant through the overflow, you may have a bad radiator cap. There are cooling system pressure testers that can help pinpoint the sources of coolant leakage, whether it is a hose, a loose clamp or the radiator itself. The radiator caps also deteriorate over time. Check the rubber that fits down into the neck of the radiator. Try to bend it to see if it breaks, or not. Usually, the rubber gets brittle and hard. Bending it will cause it to break. This means you need a new cap. Or, it could just be that the cap isn't the correct one and isn't designed to hold the pressure that your system needs to maintain. Caps are cheap...get a new one if you have any questions about yours. Besides, winter is right around the corner and having a good cooling system is just as important in winter as it is in summer. Low coolant will deprive your heater of any water to keep you warm. Usually, coolant recovery systems use a different cap that will maintain the pressures and let the excess vent to the capture vessel. As the engine cools down, a siphon will be created that will suck the overflow coolant back into the radiator. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

10-08-2007, 06:50 PM	#5
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	Re: Radiator over flow question Wasn't there a thread on here sometime back where someone used a windshield washer bottle for the overflow? __________________ 1997 GMC Sierra Ext 1965 Mustang

10-08-2007, 07:50 PM	#6
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Radiator over flow question Probably....or so my memory stick is saying so....but I'd be a bit leery of using it to capture hot coolant. I'd go with a better sort of vessel than a windshield washer bottle, but that's me. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

10-08-2007, 06:13 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Radiator over flow question no factory offerings, just dealer installed ones. Your coolant level should be one to two inches below the cap. If it's that low and still pukes, you may have an overheating problem.

10-08-2007, 09:05 PM	#7
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	Re: Radiator over flow question My '69 has an overflow bottle mounted over the driver side fender well, looks factory/dealer installed. I'll try and get a pic of it... __________________ Beat it to fit, Paint it to match...

10-08-2007, 09:12 PM	#8
tcb-1 Nothing to see here..... Join Date: Jun 2007 Location: Shawnee, KS Posts: 4,625	Re: Radiator over flow question hogrocket, had the same problem. I posted about two weeks ago wondering what others were using for a "burp" bottle. my 350 burps a little each time it gets really warm. someone mentioned the windshield washer bottle trick. then some owners have simply order one from Jeg's/Summit. someone correct me if I'm wrong, but you will need to install a radiator cap that allows the flow to re-enter the radiator after the overflow enters the burp bottle. good luck. post on your final decision 'cause I'm needing the same advise! Last edited by tcb-1; 10-08-2007 at 09:13 PM.

10-08-2007, 10:47 PM	#9
aventur1 Registered User Join Date: Aug 2007 Location: Boise, Idaho Posts: 676	Re: Radiator over flow question On my 71, which I'm the 3 owner and I'm guessing this is where they mounted it. I've seen other photos that do not have the bottle and there's a hole in the fender where one would go. Don't know? As you see mines on the passenger fender. Attached Images

10-08-2007, 10:55 PM	#10
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	Re: Radiator over flow question PICKMUP sells a nice kit for our trucks!. I'm planning to run a JAZ bottle mounted to my core support. They run about $20 and they have them in the overflow type and the recovery type. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads Last edited by 70c10; 10-08-2007 at 10:55 PM.

10-09-2007, 01:49 AM	#12
hogrocket Junior Member Join Date: Apr 2006 Location: San Diego Posts: 100	Re: Radiator over flow question I think mine is just "burping" as it does not run hot (around 190) and not that much coming out. I just don't like the dripping. I think I will go to the pick-a- part and find an overflow bottle and mount it on the lower rt side. I'll change the cap also. Thanks for all the advice. MM

10-09-2007, 07:11 AM	#13
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	Re: Radiator over flow question hogrocket- if you go to the junkyard, I think there was a post a long time ago about a 1981 Malibu bottle working good on our trucks. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

10-09-2007, 05:23 PM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Radiator over flow question 72bluz, you are absolutly correct. Har hardly ever see that issue at the shop i work at, however, we don't work on stuff this old either. good call

10-09-2007, 05:33 PM	#15
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: Radiator over flow question I,VE got some new caps made for overflow bottle use. there genuine GM and will fit a washer bottle perfect. there obsoliete now from gm. there 16.00 each delivered for a cap. __________________ I BELIEVE IN JOHN 3:16

10-09-2007, 09:12 PM	#17
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: Radiator over flow question here it is... all i have left are the clear ones now. there identicle except for color. bob Attached Images __________________ I BELIEVE IN JOHN 3:16 Last edited by BCOWANWHEELS; 10-09-2007 at 09:13 PM.



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10-09-2007, 11:16 PM	#18
PICKMUP "Trucks with Class" Join Date: Jul 2000 Location: OLYMPIA, WA, USA Posts: 8,125	Re: Radiator over flow question Sorry, I don't have any more for sale...caps are all gone! They really look good in a clean engine compartment, if you don't want the "bling" of the polished aluminum. They match the WS bottle on the other side, bracket & bottle, so they look stock...like they belong there. Run a 3/8" hose to the radiator overflow tube. Plug the extra hose nipple and drill a small vent hole on top of the plastic cap. You don't need a second hose. Although there may be some kind of special recirculation radiator caps available, (that we don't seem to be able to accurately identify), I have found the stock cap seems to work fine. The fluid in the bottle goes up hot and back down into the rad when cool. The GM part is #340194. There are still a few of these left in local dealers. Some are black/some are clear. Attached Images Last edited by PICKMUP; 10-09-2007 at 11:18 PM.

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