The small puddle of coolant on the floor was all the motivation I needed to make the decision to replace the copper radiator with an aluminum unit by Champion.
After exploring different options, I made a few calls to find out more specific details. Unfortunately, most companies seemed to be too busy taking care of other customers to answer the phone, so I kept calling until someone answered, and I hit paydirt with ChampionRadiators.com.
I spoke with Justin, and he was quite knowledgeable about what radiator would work best for my '76 Corvette based on my requirements.
My wants list included:
- A direct-fit radiator (no mods or special brackets required).
- A heavy-duty unit (my car has a/c and I use it a lot).
- Use the same size radiator hoses.
SIZE MATTERS
During my research, I learned that a 2-row radiator with 1-inch tubes is more efficient at cooling than a 3-row with 5/8-inch tubes (source: Summit Racing).
However, the 3-row radiator by Champion uses 3/4-inch tubes, which equals 2.25 inches total versus just 2 inches for the 2-row. In other words, this 3-row radiator offers more cooling capacity than a 2-row.
I spent quite a bit of time and effort trying to ensure my 5-year-old copper radiator was clean and free of blockages inside. Unfortunately, it started leaking shortly after I replaced the hoses.
It wasn't a huge leak, but that's how big leaks start. I haven't been able to pinpoint the exact location but it doesn't matter. I had also spotted a tiny leak starting around one of the transmission cooler ports. Mine has brass plugs, and the top one started weeping which means the pipe was starting to fail.
In addition to all that, a blockage inside the radiator may also lead to erratic gauge readings, and since I've already replaced pretty much every other single component, this was the last one on that long list.
The remaining question is, would a new radiator, aluminum or otherwise, resolve my Vette's overheating issues?
Only one way to find out!
REMOVING THE HOOD
Before the radiator comes out, the hood must be removed to make room. Then, the radiator along with the shroud can be safely removed. This job can be done by a do-it-yourselfer at home, but having a helper will make the task easier.
I've heard that some people replace their radiators without removing the hood, but I really think that not having it in the way makes the task a lot easier. So, if you decide to remove the hood, you will definitely need someone to help you to avoid damaging the hood and/or the car.
If you do not have anyone available to assist you, you may want to hire a mobile mechanic to help you with the swap. Spending a couple hundred dollars is far cheaper than repairing and repainting body panels, and having someone knowledgeable helping you may a good idea.
This is a list of the items I removed or loosened, plus things I did to prep the radiator for removal:
- Hood (removed)
- Air cleaner assembly and flex tube (removed)
- Air intake snorkel (removed)
- Radiator fan (removed)
- Outer brackets (2) that secure the condenser to the core support (removed)
- Inner brackets (2) that clamp the radiator to the core support (removed)
- Radiator core support bolts (removed 4 top/middle, loosened 2 lower)
- Shroud bolts (2) that secure it to the core support from underneath (removed)
- Core support ground wire (disconnect)
- Drain radiator coolant
- Disconnect upper radiator hose from radiator inlet
- Disconnect lower radiator hose from radiator outlet
With all items on the list above checked, the radiator was removed from the car. It is not really heavy, about 30 lbs., but it is awkward, so having a helper is a plus.
I also removed the fan to give myself plenty of room to also remove the radiator shroud in one piece. I know that some resort to cutting theirs in half, but that approach was not an option for my car and totally out of the question.
I held the hood in place with a painter's extension pole while I removed the two bolts that attach the hood support to the hood. I also loosened the four bolts that secure the hood hinges to the hood but left two in place, one on each side, to make removal easier.
Lastly, I taped a piece of paper towel folded over a couple of times as a cushion between the hood edges and the fenders. This simple safeguard can help prevent chips and scratches.
With all the prep work out of the way, I recruited my neighbor Joe who's never worked on cars before but was eager to give me a hand nonetheless. I just made sure to explain each step in advance and told him that WE (not the hood) were going to be controlling the removal process.
We loosened the bolts and laid the hood safely on the table I had set up for that purpose.
REMOVING THE RADIATOR
Well, I am getting a little bit ahead of myself here since many other components may need to be loosened and/or removed before the old radiator can come out.
Also, if your Corvette has air conditioning as mine does, the condenser will be in the way and it can also get damaged during this procedure. I averted this problem by removing the headlamp actuators which to some may seem extreme but something that was a smart idea in my case, as I did not want to damage the condenser since I have a working a/c system in my Vette.
As you probably know, I work alone, so I did not have a lot of time to take photos of each and every step. However, I did film a video, which due to the complexity of the whole process, had to be broken into several parts resulting in a series.
Part one of the 6-part series is at the end of this post.
To remove the shroud and radiator, I removed the headlamp actuators as previously mentioned. This allowed me to tilt the radiator support and the condenser forward enough which gave enough room for the shroud to come out in ONE piece, followed by the radiator.
As you probably know, the radiator core support is secured in place by six bolts, three per side. I removed the top and middle two from each side and loosened the remaining bottom two. This allowed me to pivot the whole assembly forward enough so the shroud could be removed intact.
Not having the actuators in the way also eliminated the chance of damage to the condenser. The picture above shows the headlamp actuators in place, and when you tilt the core support forward, the ac condenser vanes get squished against them. As a matter of fact, mine had plenty of old scarring from work performed by others.
INSTALLING THE RADIATOR
I did not want the new radiator vanes damaged, so I protected both sides with cardboard from the box the rad came in. This was an excellent idea and my aluminum radiator is flawless.
I had to modify one of the lower mounting brackets though since it was interfering with the radiator drain petcock. I used my Dremel tool to trim a sliver off the side that was creating the issue, and that took care of that problem. I also gave the bracket a coat of paint to prevent rust.
With the new radiator in place, I took advantage of not having the shroud blocking the way and installed the lower radiator hose. This is the perfect time for this mod.
I then reinstalled the shroud and removed all the protective cardboard and paper from the radiator.
I also relocated one of the ground contacts to a more accessible spot on the core support.
The Champion 3-row aluminum radiator is a direct fit, for the most part, so all brackets and rubber pads fit properly and in the same location. This makes installation a lot easier.
I also reattached the two core-support-to-hood seals. These seals are very important as they block ram air and redirect it toward the radiator instead of being wasted in the engine bay. Again, this is the perfect time to replace all the radiator seals as they are crucial to the proper operation of the car.
RADIATOR SWAP VIDEO SERIES
If a picture is worth a thousand words, then a video is worth a million.
And while it's impossible for a one-man operation to film every detail, the videos—along with the info in this article—will give you a better understanding of what's involved, and the steps necessary to swap your C3 Corvette's radiator.
The video above is Part 1 of a six-episode series that I've uploaded to my YouTube channel.
Swapping a C3 Corvette radiator is what I call an "Advanced DIY project." But don't let that description scare or discourage you.
I had never swapped one until now and, although challenging, it is doable as shown in my videos. And the job was done right!
Having the QuickJack portable lift makes the job more manageable (not easier), and it also saves quite a bit of time. But this project can also be done with the proper floor jack and jack stands. Not as safe or as fast compared to the lift, but it can be done.
I am sure a qualified mechanic would charge a lot of money for this job, so you may want to get a quote before you let someone start wrenching on your car. Besides, the money you save can be used to purchase a QuickJack, so that's something to consider.
Anyway, I hope you find the article and videos to be informative.
Thank you for following my 76vette Blog!