Antifreeze leak... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**68350** · 09-17-2011, 07:24 PM

First off, wanted to say a much deserved thanks to the members who helped me diagnose my bad hei control module. Now on to my next problem. Antifreeze leaks out of the bottom of my a/c box(heater box mounted to firewall) when the motor gets to operating temperature. It leaks for a while, then stops(basically stops when the motor cools off after shut down). Today, I noticed smoke coming through the inside heater vents and it smelled like antifreeze, so I'm guessing it has something to do with my leak. Any ideas on what is bad/leaking? I'm guessing heater core, but I don't feel like tearing that a/c box off unless I have to. thanks

**leddzepp** · 09-17-2011, 07:28 PM

Bad heater core

PanelDeland · 09-17-2011, 08:31 PM

I agree.It's also time to fix it since you will need the Defrost in ND this winter.No sense in waiting until it's an emergency.Although,you can loop the heater hose back to the block to keep it from leaking until you get one.Mine was non-AC so it's a different deal to change out.

**68350** · 09-17-2011, 08:43 PM

Thanks, I guess I'll rip the a/c box off and replace it. PanelDeland, it's on my almost finished cheyenne super, it won't see the snow haha. thanks for the input guys.

Longhorn Man · 09-17-2011, 09:14 PM

have fun with that... it's actually on the inside of the firewall. Non A/C is on the outside, but A/C trucks have it inside. Real PITA to do, but not nearly as bad as late model vehicles.

fastwillie 696969 · 09-18-2011, 12:32 AM

Quote:

Originally Posted by Longhorn Man

have fun with that... it's actually on the inside of the firewall. Non A/C is on the outside, but A/C trucks have it inside. Real PITA to do, but not nearly as bad as late model vehicles.

like a Lincoln.cont. got 10 hrs to change one on warranty ,theres only one million screws to take out

Longhorn Man · 09-18-2011, 05:29 AM

yeah... nothing even close to a late model. You don't have to remove the dash at all on these (not that you could anyways)... but it's still more of a pain that the non A/C trucks

rsavage · 09-18-2011, 07:28 AM

I would get some help to remove the hood and take the right inner fender and tire and wheel off. The right hood hinge may have to come off the fender too for clearance. It will still be a pita but it will reduce swearing and greatly improve access.

Longhorn Man · 09-18-2011, 08:45 AM

I don't think I had to do any of that on an A/C truck... just on a non A/C truck

Fantom · 09-18-2011, 09:13 AM

Mine started leaking yesterday

It's an a/c equipped truck, not looking forward to changing it out.

Any tips to make it a little easier?

GASoline71 · 09-18-2011, 01:14 PM

Get a few friends, a cooler full of beer, and some pizza...

Gary

Fantom · 09-18-2011, 03:38 PM

lol, yeah that couldn't hurt.....wasn't actually too bad, had it apart in about 30 minutes. Worse part was trying to get my brand new glove box out without tearing it.

09-17-2011, 07:24 PM	#1
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Antifreeze leak... First off, wanted to say a much deserved thanks to the members who helped me diagnose my bad hei control module. Now on to my next problem. Antifreeze leaks out of the bottom of my a/c box(heater box mounted to firewall) when the motor gets to operating temperature. It leaks for a while, then stops(basically stops when the motor cools off after shut down). Today, I noticed smoke coming through the inside heater vents and it smelled like antifreeze, so I'm guessing it has something to do with my leak. Any ideas on what is bad/leaking? I'm guessing heater core, but I don't feel like tearing that a/c box off unless I have to. thanks __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

09-17-2011, 07:28 PM	#2
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,997	Re: Antifreeze leak... Bad heater core __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man

09-17-2011, 08:31 PM	#3
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: Antifreeze leak... I agree.It's also time to fix it since you will need the Defrost in ND this winter.No sense in waiting until it's an emergency.Although,you can loop the heater hose back to the block to keep it from leaking until you get one.Mine was non-AC so it's a different deal to change out. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

09-17-2011, 08:43 PM	#4
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: Antifreeze leak... Thanks, I guess I'll rip the a/c box off and replace it. PanelDeland, it's on my almost finished cheyenne super, it won't see the snow haha. thanks for the input guys. __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

09-17-2011, 09:14 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Antifreeze leak... have fun with that... it's actually on the inside of the firewall. Non A/C is on the outside, but A/C trucks have it inside. Real PITA to do, but not nearly as bad as late model vehicles.

09-18-2011, 05:29 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Antifreeze leak... yeah... nothing even close to a late model. You don't have to remove the dash at all on these (not that you could anyways)... but it's still more of a pain that the non A/C trucks

09-18-2011, 07:28 AM	#8
rsavage Registered User Join Date: Aug 2009 Location: Alden NY Posts: 2,705	Re: Antifreeze leak... I would get some help to remove the hood and take the right inner fender and tire and wheel off. The right hood hinge may have to come off the fender too for clearance. It will still be a pita but it will reduce swearing and greatly improve access. __________________ 1961 C1 Corvette 1959 El Camino 350 TPI, 9" 4 w disc 69 Blazer K5 - sold July '20 2021 Durango RT 5.7

09-18-2011, 08:45 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Antifreeze leak... I don't think I had to do any of that on an A/C truck... just on a non A/C truck

09-18-2011, 09:13 AM	#10
Fantom Registered User Join Date: Sep 2011 Location: Hattiesburg, Ms Posts: 65	Re: Antifreeze leak... Mine started leaking yesterday It's an a/c equipped truck, not looking forward to changing it out. Any tips to make it a little easier?

09-18-2011, 03:38 PM	#12
Fantom Registered User Join Date: Sep 2011 Location: Hattiesburg, Ms Posts: 65	Re: Antifreeze leak... lol, yeah that couldn't hurt.....wasn't actually too bad, had it apart in about 30 minutes. Worse part was trying to get my brand new glove box out without tearing it.



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