Leaky radiator - The 1947 - Present Chevrolet & GMC Truck Message Board Network

OUbesto · 04-13-2020, 02:30 PM

I have a small pinhole in my radiator that seems only leaks when ambient temp is over 80. Anyone have any suggestions for an additive I can use in my rad to stop leak? Can I take it to a rad shop for them to fix?

1970 402 w/AC, AT 400TH

**FirstOwner69** · 04-13-2020, 02:39 PM

This is what GM recommends. It's effective and doesn't gum things up and is widely available. This came up with a quick search. If it doesn't work, take the radiator in for a simple repair.

https://www.walmart.com/ip/GM-Coolin...yABEgLDTfD_BwE

OUbesto · 04-13-2020, 02:45 PM

Thanks Jim.

Wrenchbender Ret · 04-13-2020, 03:29 PM

Bars Leak is good also. It is available at all parts stores.

weq92f · 04-13-2020, 04:05 PM

.

Results from Mythbusters episode where they tested the 'ol egg in radiator to stop leak...

When there is a leak in a car radiator, cracking an egg into the radiator will plug the hole.
PLAUSIBLE

The engine was started after the contents of an egg were poured in, and the leak stopped.

Just sayin'...

-klb

EDIT: https://mythresults.com/episode15

toolboxchev · 04-14-2020, 12:39 PM

Mark the hole, pull the radiator and solder it up.

Everyone wants a pill to fix problems, myself included. Go through the pain, and get it over with. Or.....

rockyrivermark · 04-14-2020, 05:28 PM

Quote:

Originally Posted by toolboxchev

Mark the hole, pull the radiator and solder it up.

Everyone wants a pill to fix problems, myself included. Go through the pain, and get it over with. Or.....

What he said.
Get a little flux in there first

OUbesto · 04-15-2020, 09:13 AM

Good ideas....thanks guys!

lok-dawg · 04-17-2020, 07:10 PM

Quote:

Originally Posted by toolboxchev

Mark the hole, pull the radiator and solder it up.

Everyone wants a pill to fix problems, myself included. Go through the pain, and get it over with. Or.....

100% agree with this ... had a leaky radiator in mine about 10 years ago. Contemplated repairing it but figured more leaks could easily show up in the near future so I opted to buy a new one and do not regret the decision one bit. However I think I paid about $100 less than what parts stores charge today.

And based on my experience, I would NOT use Bars Leak unless an absolute emergency just to get you back to civilization.

**Corts60** · 04-17-2020, 07:17 PM

Quote:

Originally Posted by weq92f

.

Results from Mythbusters episode where they tested the 'ol egg in radiator to stop leak...

When there is a leak in a car radiator, cracking an egg into the radiator will plug the hole.
PLAUSIBLE

The engine was started after the contents of an egg were poured in, and the leak stopped.

Just sayin'...

-klb

EDIT: https://mythresults.com/episode15

This works! it got me home a long time ago when a crack developed in the radiator on my old Toyota. It wasn't completely leak free, but it worked enough to get home.

But definitely pull the radiator and solder the correct way as mentioned above. Only way to go.

04-13-2020, 02:30 PM	#1
OUbesto Registered User Join Date: Oct 2015 Location: Lincolnshire, IL / Burlington, WI Posts: 209	Leaky radiator I have a small pinhole in my radiator that seems only leaks when ambient temp is over 80. Anyone have any suggestions for an additive I can use in my rad to stop leak? Can I take it to a rad shop for them to fix? 1970 402 w/AC, AT 400TH __________________ 1970 C-10 CST, LWB, 402/400, A/C

04-13-2020, 02:39 PM	#2
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,852	Re: Leaky radiator This is what GM recommends. It's effective and doesn't gum things up and is widely available. This came up with a quick search. If it doesn't work, take the radiator in for a simple repair. https://www.walmart.com/ip/GM-Coolin...yABEgLDTfD_BwE __________________ Jim

04-13-2020, 02:45 PM	#3
OUbesto Registered User Join Date: Oct 2015 Location: Lincolnshire, IL / Burlington, WI Posts: 209	Re: Leaky radiator Thanks Jim. __________________ 1970 C-10 CST, LWB, 402/400, A/C

04-13-2020, 03:29 PM	#4
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: Leaky radiator Bars Leak is good also. It is available at all parts stores.

04-13-2020, 04:05 PM	#5
weq92f Registered User Join Date: Oct 2016 Location: Dallas Texas Posts: 3,227	Re: Leaky radiator . Results from Mythbusters episode where they tested the 'ol egg in radiator to stop leak... When there is a leak in a car radiator, cracking an egg into the radiator will plug the hole. PLAUSIBLE The engine was started after the contents of an egg were poured in, and the leak stopped. Just sayin'... -klb EDIT: https://mythresults.com/episode15 __________________ 67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold

04-14-2020, 12:39 PM	#6
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Leaky radiator Mark the hole, pull the radiator and solder it up. Everyone wants a pill to fix problems, myself included. Go through the pain, and get it over with. Or.....

04-15-2020, 09:13 AM	#8
OUbesto Registered User Join Date: Oct 2015 Location: Lincolnshire, IL / Burlington, WI Posts: 209	Re: Leaky radiator Good ideas....thanks guys! __________________ 1970 C-10 CST, LWB, 402/400, A/C



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