Aluminum radiator rebuild

[Brian M.]

Hello,
I am a new member and the proud owner of a 1965 396/425 car. I would like to have the original aluminum radiator rebuilt if possible. Can anyone suggest a repair faciltity that can do this? Should I consider replacing the original with a Dewitt's or similar new radiator? Does this take away the originallity of the car?

Thanks for the help and any advise.

Sincerely,
Brian McNamara

[Gary S.]

Re: Aluminum radiator rebuild

Brian,
If you have an original Harrison aluminum radiator, I don't believe anyone can rebuild this. I had a 66 with a worn out rad and my archive research turned up information from others smarter than me (that's just about everyone ) that said your radiator is now a museum piece. Of course, that was 10+ years ago. Maybe things have changed?

Oth, DeWitts makes a GREAT repro radiator. A new repro unit from DeWitts allowed me to finally enjoy my 66 without overheating. I wouldn't consider anything less than a new radiator. Even if you could find someone to fix the old one, you are dealing with a 43 year old rad.

[Alan S.]

Re: Aluminum radiator rebuild

Hi Brian,
I wanted very much to save the aluminum radiator from my 71. It still looked great but would 'weep' in the lower corners just enough to put two spots on my garage floor. No one offered me any hope of repairing it. At the time, Tom De Witt had not yet developed his reproduction. There was an new aluminium radiator going from swap meet to swap meet for a few years with a price tag of $2500.00. I passed on it.!?!?
I waited a few years as Tom reduced the price of his new reproduction and then bought one.
I'm really pleased with it!
Regards,
Alan

[Stuart F.]

Re: Aluminum radiator rebuild

Not to mention they can be date coded for a little extra. Add the correct stickers and you are ready to go.

Stu Fox

[Joe L.]

Re: Aluminum radiator rebuild

Hello,
I am a new member and the proud owner of a 1965 396/425 car. I would like to have the original aluminum radiator rebuilt if possible. Can anyone suggest a repair faciltity that can do this? Should I consider replacing the original with a Dewitt's or similar new radiator? Does this take away the originallity of the car?

Thanks for the help and any advise.

Sincerely,
Brian McNamara

Brian-----

As others have mentioned, there is no way to "rebuild" a 1960-72 Corvette aluminum radiator. They can be repaired in some cases, but I never recommend doing this. You would then have what I would call an unreliable radiator. In other words, the next leak will be right around the corner and who knows where it's going to occur?

DeWitts reproductions ARE THE ANSWER. Period. And be VERY grateful that they are available.

[Duke W.]

Re: Aluminum radiator rebuild

There's no way to rebuild these aluminum radiators. There are two failure mechanisms - seepage/leaks due to corrosion and loss of heat transfer capacity due to deposit buildup in the tubes.

Consider that your current radiator is 45 years old. Use modern HOAT antifreeze with proper change intervals and a new DeWitt's will probably last at least 50 years.

Be sure to use new rubber mounting grommets - two at the bottom, one up top - with the new radiator. They perform two critical functions - shock mounting and electrical isolation of the radiator.

I don't think a date-stamped DeWitts typically loses any points in Flight judging.

Duke

[John D.]

Re: Aluminum radiator rebuild

Brian, Aluminum rads don't age very well. If you just want a temporary repair and I mean temporary go visit one of the big truck places and get their suggestions on where to go in your area for a patch job.
Best thing is to listen to the other posts and buy a DeWitt radiatior. No deductions for those at all except maybe for cheep decal. I have my original 63 B rad stashed in a closet and a nice DeWitt on the car. The car runs very cool with it. The original leaked like Niagara Falls. I remember taking it to a few repair shops and no one would touch it. So back in the old days I bought a GM one dated 1976 and used it until a recent resto on the car and then got Tom DeWitts work of art. If it were not for Tom we would be in grave trouble here. Order one today. You will be pleased. John

[Jim D.]

Re: Aluminum radiator rebuild

Be sure to use new rubber mounting grommets - two at the bottom, one up top - with the new radiator. They perform two critical functions - shock mounting and electrical isolation of the radiator.

Duke

I thought you didn't want it to be isolated because the coolant would then become a source of conductivity and the rad. would be eaten from the inside out. New cars have a ground strap to the rad. and there are service bulletins that state if the strap isn't attached when a repair is made, the rad. will end up being destroyed.
Every source I can find states to make sure the rad. is grounded to the frame and for extra protection, use a sacraficial zinc anode in place of the drain plug. This is very important with all the different materials used today.
Your comments would be appreciated.

Jim

[Joe L.]

Re: Aluminum radiator rebuild

I thought you didn't want it to be isolated because the coolant would then become a source of conductivity and the rad. would be eaten from the inside out. New cars have a ground strap to the rad. and there are service bulletins that state if the strap isn't attached when a repair is made, the rad. will end up being destroyed.
Every source I can find states to make sure the rad. is grounded to the frame and for extra protection, use a sacraficial zinc anode in place of the drain plug. This is very important with all the different materials used today.
Your comments would be appreciated.

Jim

Jim------


GM went to great lengths to design the 63-72 aluminum radiator support system so that the radiator was completely isolated from contact with any other metals OR any grounding, whatsoever. It is critical to maintain this or galvanic corrosion will wipe out the radiator very rapidly.

Newer cars are engineered and designed differently and grounding of the radiator may be part of that design. However, this is NOT applicable to earlier Corvette aluminum radiators.

[Jim D.]

Re: Aluminum radiator rebuild

What about the 60-62 Corvette's with aluminum radiators? They aren't isolated. Or is that how GM learned of the problem?

Jim

[Alan S.]

Re: Aluminum radiator rebuild

Hi Joe L.,
I appreciate you information. I always thought (never asked) the rubber insulators were there to stop vibration. I 'assumed' the vibration would fatigue the aluminium or the way the radiator was built in some way. Thanks!
Regards,
Alan

[Duke W.]

Re: Aluminum radiator rebuild

My Harrison radiator had pin hole leaks in less than 15 years, despite bienniel coolant changes.

I attribute this to the fact that the factory left off the upper grommet, which allowed the radiator to electrically connect to the vehicle ground.

Look at it this way. If you take an anode and cathode and immerse them in an electrolyte, there is no signficant galvanic action until you connect the two electrodes - either with a load or just short them. Then you have a battery that will eat one electrode away. In the case of a Corvette you have an aluminum electrode - and an iron electode - the block. Immerse them in an electrolye and you have a battery. It's a matter of whether the two electrodes are connected. If so, the aluminum is what is sacrificed and there is not much there compared to the mass of cast iron. If the aluminum electode is not electically connected to the iron electrode, there is no galvanic action - or at least it is very slow.

I don't know about modern cars, but if you do a continuity check on a properly mounted C2 aluminum radiator between the radiator and battery negative post, you should find that they are isolated, and given my experience, I recommend keeping it that way. The same applies to the expansion tank. Keep it isolated from vehicle ground.

Duke

[Jimmy G.]

Re: Aluminum radiator rebuild

Buy a Dewitts and put the old one in the attic for a reference. Only way to go.

[Stuart F.]

Re: Aluminum radiator rebuild

I lost my original in 12 years, but I thought it was the Xerex Anti-Freeze that was the cause as the leaks began with a change to Xerex - I have posted a thread about this before. But the discussion about the isolation mounts caused me to recall mine too came w/o a rubber mount in the top. I only discovered it by chance while breezing through an assembly manual. Like "hey! mine don't have one of those!" My radiator had a little play in it, but not to the point that I thought it excessive.

Perhaps the real culprit has finally been discovered. Thanks guys for bringing this up.

Stu Fox

[Duke W.]

Re: Aluminum radiator rebuild

...exact same thing with me!

I did not realize there should be a grommet on the top mount until I bought an AIM in the mid seventies and saw it called out, but by that time my radiator was showing evidence of seepage.

And with a little basic chemistry analysis...

I wonder how many '63s left the plant without that grommet. Mine was built on March 19.

Duke