anti freeze leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

superman3405 · 03-20-2008, 03:10 AM

So my truck has been sitting for a while to get some body work done. Under the truck back almost under the cab there is a spot of leaking antifreeze. What back there could/would be leaking?

**El Jay** · 03-20-2008, 03:26 AM

"Freeze" plug on the back side of the block.

tcb-1 · 03-20-2008, 03:26 AM

the only thing back that far would be your heater lines and heater core. what side it the leak on? if it's the passenger, then it's either of the two I mentioned.

trace the leak if you can to rule out a leaky freeze plug as well.....

superman3405 · 03-20-2008, 04:09 AM

it is on the drivers side right around the oil filter. The freeze plug?? How does that end up leaking?

**WorkinLonghorn** · 03-20-2008, 06:09 AM

Quote:

The freeze plug?? How does that end up leaking?

Some people just run straight water and the steel freeze-plugs (among other things) rust away.
I did this when I was a kid and didn't know that anti-freeze contains a rust inhibiter plus lubricates the water pump.

superman3405 · 03-20-2008, 06:15 AM

are there any other issues other than needing to replace the plug I should look out for? Since the plug busted it would not have any affect on my motor would it? it is fairly new and i would hate to have to pull it

71Farmtruck · 03-20-2008, 06:39 AM

If you did not overheat it then no, there should be no issue. If it is the plug fix it, the leak will get worse.

superman3405 · 03-20-2008, 06:41 AM

okay, just trying to ease my worries, the truck has not been cranked up for at least 2 months

Longhorn Man · 03-20-2008, 06:42 AM

and if it is the plug, and if it is caused from rust, stick your finger up in there once you remove the plug... see if there is rust sludge build up... if there is, you'll want to try and remove all of it.

**El Jay** · 03-20-2008, 06:44 AM

Quote:

Originally Posted by superman3405

are there any other issues other than needing to replace the plug I should look out for? Since the plug busted it would not have any affect on my motor would it? it is fairly new and i would hate to have to pull it

There is some stuff called "K-W Block Seal(er)" that works real good. But you have to follow the directions exactly. ABSOLUTELY no antifreeze in the system when you use it. You have to flush, reflush, and reflush the cooling system to get rid of the antifreeze.
After that do EXACTLY what the directions on the can say.

You can run with a leaky freeze plug, if it's not too bad; but check the coolant level at least once/day.

To replace the freeze plug, you're either going to have to drop the transmission, or pull the engine.
If you drop the transmission, replace both freeze plugs on the back of the block. If one is bad, how far behind is the other?

If you pull the engine, replace them all. Refer back to previous comment about "If one is bad....."

Well, I hope I helped you a little bit.

El Jay

cruiserman · 03-20-2008, 06:56 AM

Good opportunity to put in a block heater.

Longhorn Man · 03-20-2008, 07:32 AM

Quote:

Originally Posted by cruiserman

Good opportunity to put in a block heater.

true... but shouldn't be needed in Tennessee

superman3405 · 03-20-2008, 07:56 AM

naa no need for a block heater here. The truck has been sitting for 2-3 months. We had a bad cold spell here back in Feb. so that may have done it. Who knows, I will pop a new one in once I get it painted. Thanks guys

Ole Blue 68 · 03-20-2008, 06:20 PM

Also, if you do wind up replacing those plugs, I'd recommend going with brass plugs. They last longer than the steel.

tcb-1 · 03-20-2008, 08:56 PM

Quote:

Originally Posted by Ole Blue 68

Also, if you do wind up replacing those plugs, I'd recommend going with brass plugs. They last longer than the steel.

x 2

and they do not rust!

jgrh64 · 03-20-2008, 10:39 PM

I've noticed that usually the only one to leak is the hardest one to get to

Longhorn Man · 03-21-2008, 02:48 AM

I totally agree on the brass.
And I also agree, the leaky ones are over starters every time.

Husker · 03-21-2008, 07:34 AM

I have one leaking also. If ya take the Exhaust manifold off can't ya get to it ok?
Ron

superman3405 · 03-21-2008, 09:16 PM

Well....climbed under the truck today and this ?#%^$* plug is in the most difficult spot to get to. I think I am going to have to pull the motor. I will deal with that later.
I see there are brass plugs and rubber plugs. Are the rubber ones any better?

**70STOVEBOLT** · 03-21-2008, 09:37 PM

The rubber ones are the expandable type. I would not recommend using that, except maybe as a temporary fix. The freeze plug is there to prevent the block from cracking if the water in the cooling system freezes and expands. The idea is that the plug will pop out before the block cracks. If you use the rubber one, it can't pop out. Freezing would probably not be a problem in TN tho.

**El Jay** · 03-22-2008, 09:43 AM

Quote:

Originally Posted by 70STOVEBOLT

The rubber ones are the expandable type. I would not recommend using that, except maybe as a temporary fix. The freeze plug is there to prevent the block from cracking if the water in the cooling system freezes and expands. The idea is that the plug will pop out before the block cracks. If you use the rubber one, it can't pop out. Freezing would probably not be a problem in TN tho.

The "freeze" plug is not a freeze plug.

The holes are there to let the sand out of the block casting.

LONGHAIR · 03-22-2008, 04:58 PM

Quote:

The "freeze" plug is not a freeze plug.

The holes are there to let the sand out of the block casting.

While they will let the sand out....technically they are there to hold the cores in place from the outside.

71Farmtruck · 03-24-2008, 04:01 AM

Brass is a non-ferrous metal, it cant rust.

Also, if that plug is in a bad place there is a tool you can get that has the plug seater on a swivel so you can whack it in at an angle with a hammer.

**El Jay** · 03-24-2008, 08:56 AM

Quote:

Originally Posted by LONGHAIR

While they will let the sand out....technically they are there to hold the cores in place from the outside.

Point taken.
I just wanted to make sure that he didn't use a "freeze" plug for cold weather engine protection.

03-20-2008, 03:10 AM	#1
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	anti freeze leak So my truck has been sitting for a while to get some body work done. Under the truck back almost under the cab there is a spot of leaking antifreeze. What back there could/would be leaking? __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky

03-20-2008, 03:26 AM	#2
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: anti freeze leak "Freeze" plug on the back side of the block. __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

03-20-2008, 03:26 AM	#3
tcb-1 Nothing to see here..... Join Date: Jun 2007 Location: Shawnee, KS Posts: 4,625	Re: anti freeze leak the only thing back that far would be your heater lines and heater core. what side it the leak on? if it's the passenger, then it's either of the two I mentioned. trace the leak if you can to rule out a leaky freeze plug as well..... __________________ Doug THANK YOU to our American Soldiers & Veterans - POW MIA "You will NEVER be forgotten". The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. Thomas Jefferson

03-20-2008, 04:09 AM	#4
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	Re: anti freeze leak it is on the drivers side right around the oil filter. The freeze plug?? How does that end up leaking? __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky

03-20-2008, 06:15 AM	#6
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	Re: anti freeze leak are there any other issues other than needing to replace the plug I should look out for? Since the plug busted it would not have any affect on my motor would it? it is fairly new and i would hate to have to pull it __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky

03-20-2008, 06:39 AM	#7
71Farmtruck Junk Junkie Join Date: Oct 2007 Location: Humble, TX Posts: 123	Re: anti freeze leak If you did not overheat it then no, there should be no issue. If it is the plug fix it, the leak will get worse. __________________ Mike 71 Chevrolet C-10 Short Bed Stepside 81 GMC 1500 Sierra Classic Long Bed

03-20-2008, 06:41 AM	#8
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	Re: anti freeze leak okay, just trying to ease my worries, the truck has not been cranked up for at least 2 months __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky

03-20-2008, 06:42 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: anti freeze leak and if it is the plug, and if it is caused from rust, stick your finger up in there once you remove the plug... see if there is rust sludge build up... if there is, you'll want to try and remove all of it.

03-20-2008, 06:56 AM	#11
cruiserman Registered User Join Date: Dec 2006 Location: Idaho Posts: 210	Re: anti freeze leak Good opportunity to put in a block heater. __________________ 72 C2500 LWB 402 Sierra Grande 05 Odyssey 08 Tundra

03-20-2008, 07:56 AM	#13
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	Re: anti freeze leak naa no need for a block heater here. The truck has been sitting for 2-3 months. We had a bad cold spell here back in Feb. so that may have done it. Who knows, I will pop a new one in once I get it painted. Thanks guys __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky

03-20-2008, 06:20 PM	#14
Ole Blue 68 Registered User Join Date: Aug 2005 Location: Philly Posts: 1,140	Re: anti freeze leak Also, if you do wind up replacing those plugs, I'd recommend going with brass plugs. They last longer than the steel.

03-20-2008, 10:39 PM	#16
jgrh64 Prestige member Old Farts Club Join Date: Nov 2005 Location: Cleveland Posts: 502	Re: anti freeze leak I've noticed that usually the only one to leak is the hardest one to get to __________________ Hey sombodys gotta do it!

03-21-2008, 02:48 AM	#17
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: anti freeze leak I totally agree on the brass. And I also agree, the leaky ones are over starters every time.

03-21-2008, 07:34 AM	#18
Husker Registered User Join Date: Dec 1999 Location: Mid NE USA Posts: 2,212	Re: anti freeze leak I have one leaking also. If ya take the Exhaust manifold off can't ya get to it ok? Ron __________________ Member #111 68 C-10 Daily Driver 70 4x4 Project 76 Jeep CJ-5 Help Support the Board: http://67-72chevytrucks.com/vboard/payments.php He who knows nothing is closer to the truth than he whose mind is filled with falsehoods and errors. Thomas Jefferson

03-21-2008, 09:16 PM	#19
superman3405 Junior Member Join Date: Mar 2007 Location: Tennessee Posts: 80	Re: anti freeze leak Well....climbed under the truck today and this ?#%^$* plug is in the most difficult spot to get to. I think I am going to have to pull the motor. I will deal with that later. I see there are brass plugs and rubber plugs. Are the rubber ones any better? __________________ ------------------------------------------------- 1972 Chevy C-10 Short Bed (Ol'Blue) 350/350TH 2003 Chevy Silverado Z71 2007 Honda MiniVan...yup we should all be so lucky



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03-21-2008, 09:37 PM	#20
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,258	Re: anti freeze leak The rubber ones are the expandable type. I would not recommend using that, except maybe as a temporary fix. The freeze plug is there to prevent the block from cracking if the water in the cooling system freezes and expands. The idea is that the plug will pop out before the block cracks. If you use the rubber one, it can't pop out. Freezing would probably not be a problem in TN tho. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Power windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

03-24-2008, 04:01 AM	#23
71Farmtruck Junk Junkie Join Date: Oct 2007 Location: Humble, TX Posts: 123	Re: anti freeze leak Brass is a non-ferrous metal, it cant rust. Also, if that plug is in a bad place there is a tool you can get that has the plug seater on a swivel so you can whack it in at an angle with a hammer. __________________ Mike 71 Chevrolet C-10 Short Bed Stepside 81 GMC 1500 Sierra Classic Long Bed Last edited by 71Farmtruck; 03-24-2008 at 04:04 AM.

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