Radiator Leak - Big Block
Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
Radiator Leak - Big Block
I have a 73 big block with a small radiator leak. It's a major task taking the shroud and/or the radiator out, so I'd like to patch it if possible. Although not easy to reach, I probably could twist off a small section of the fins before patching. Any thoughts? Best type of epoxy for the job?
Thanks
Thanks
Racer
Joined: Jul 2013
Posts: 385
Likes: 3
From: Leesburg VA
Not sure how successful you will be, but you can give it a shot. Did you try Bars Stop-Leak? I will be the first to tell you that pulling the shroud and radiator is a giant PIA, but is probably the only way to truly fix it for good. Another thing to consider is that the radiator leaking onto the lower portion of the radiator core support results in significant potential for rust. If you point your flashlight through that hole and look at the bottom of the radiator, I am betting you will see rust if not holes.
You can give the epoxy and/or stop-leak a try as a temporary solution, but I believe the writing is on the wall...the radiator will need to come out. I replaced mine with an aluminum with dual electric fans and got rid of the shroud completely. Very happy with the result.
John
You can give the epoxy and/or stop-leak a try as a temporary solution, but I believe the writing is on the wall...the radiator will need to come out. I replaced mine with an aluminum with dual electric fans and got rid of the shroud completely. Very happy with the result.
John
Team Owner
Joined: Jul 2004
Posts: 40,404
Likes: 791
From: Redondo Beach, California
In my 68 Corvette, my 97 Thunderbird, my 95 Cadillac, I have 100% ethylene glycol...green stuff. It doesn't boil until you get to 350 degrees F (?). This means the pressure system is never pressurized. If there's a leak, lack of pressurization greatly minimizes leaking. My 68 has never had any water in the cooling system since about 1973. No rust.
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I think you're going to have to replace the radiator..If the leak was on the top of the engine, my all ethylene glycol would greatly help. At the bottom of the radiator, you're going to be leaking no matter what. I've pulled two radiators out of BB's. It's just a horrible experience..it helps if you sacrifice the composite plastic radiator shroud...but then where are you going to get another? For my first, I slit the plastic shroud at the bottom near the front crossmember. This helped removing the shroud. To replace it I used some 3" by 5" aluminum plates riveted to the shroud and Dzus fasterners to replace the shroud.
....................
I think you're going to have to replace the radiator..If the leak was on the top of the engine, my all ethylene glycol would greatly help. At the bottom of the radiator, you're going to be leaking no matter what. I've pulled two radiators out of BB's. It's just a horrible experience..it helps if you sacrifice the composite plastic radiator shroud...but then where are you going to get another? For my first, I slit the plastic shroud at the bottom near the front crossmember. This helped removing the shroud. To replace it I used some 3" by 5" aluminum plates riveted to the shroud and Dzus fasterners to replace the shroud.
Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
My car only has 83,000 miles and I replaced the radiator 4,000 miles / 14 years ago. I don't remember exactly how I got the shroud and radiator out and back in, but do remember what a super duper PIA it was. Considering the miles driven, or the lack of, I really don't want to go through that again if I don't have to. I'll try an epoxy first before gumming up the insides. One thought is JB Weld. Any better choices?
Safety Car
Joined: Apr 2006
Posts: 4,057
Likes: 421
From: BC
I found pulling the rad in my 69 BB to be a pretty easy job. I unbolted the hood and removed the shroud/rad/support in one unit. Remove the fan, three bolts on each side of the support, two on the bottom plus the center rod, one bolt for the ground strap, tilt the whole unit forward and lift it out. About an hour in or out and really straight forward with no swearing required.
Pro
Joined: Feb 2014
Posts: 692
Likes: 2
From: Seguin TX
Use a stop leak that is made out of walnut shells which will not GUNK up the insides or based on the pics and location of the leak, which is where the rows connect to the tank, you will be replacing that radiator.
Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
I found pulling the rad in my 69 BB to be a pretty easy job. I unbolted the hood and removed the shroud/rad/support in one unit. Remove the fan, three bolts on each side of the support, two on the bottom plus the center rod, one bolt for the ground strap, tilt the whole unit forward and lift it out. About an hour in or out and really straight forward with no swearing required.
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Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
Thanks John for the hood info.
The radiator I'm removing was from Zip Products, item #RA-108, back in 1999. Their invoice didn't have the manufacturer and they didn't know the answer when I called today. Does anyone know who made that item? I know Dewitt's has a lifetime warranty.
Thanks
The radiator I'm removing was from Zip Products, item #RA-108, back in 1999. Their invoice didn't have the manufacturer and they didn't know the answer when I called today. Does anyone know who made that item? I know Dewitt's has a lifetime warranty.
Thanks
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Thanks John for the hood info.
The radiator I'm removing was from Zip Products, item #RA-108, back in 1999. Their invoice didn't have the manufacturer and they didn't know the answer when I called today. Does anyone know who made that item? I know Dewitt's has a lifetime warranty.
Thanks
The radiator I'm removing was from Zip Products, item #RA-108, back in 1999. Their invoice didn't have the manufacturer and they didn't know the answer when I called today. Does anyone know who made that item? I know Dewitt's has a lifetime warranty.
Thanks
Thread Starter
Racer
Joined: Apr 2004
Posts: 336
Likes: 0
From: Tucson
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Actually it's a four row, you can tell by the three notches on the top rail. That's how they separate the tubes during the assembly. The end tank has no welding around it, which means it was sweat welded with lead and that means it's a copper/brass radiator. It is an aftermarket (not GM) radiator because the channel details.