CK5
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Radiator...what to do

You definitely don't want to clamp the radiator vertically. That's what supposedly killed 3 of mine.

At least if they put the "pins" as pictured for mounting ours, four drilled holes, four round bushings, and we'd be done. I don't (and wouldn't) drill holes, but if that is what it takes to prevent these things from leaking, at least it would be a decent option for those that don't mind. It wouldn't be that "unclean" if the pins went through the upper mounts.

I don't think copper/brass is going to be a cost effective alternative again and the all aluminums are hit and miss, so the evil is hit or miss all aluminum, or hit or miss plastic/aluminum, as I look at it.
 
By the way, just an update. Not sure if the aftermarket is just cheap junk (I lean towards this) or just a "feature" of plastic/aluminum units, but I noticed that with a cold cooling system, engine off, if I squeeze the upper radiator hose, the tanks visibly bulge along their entire length. Not enough to contact the core support, but it wouldn't take much more expansion for that to happen. Weird, and doesn't seem like it would help longevity of the seals, fittings, or the tanks themselves.
 
I've been running a Spectra CU730 on my '85 454 K30 for 5yrs now. Plastic and Al. Cools great and no leaks yet. Made in Canada. I'm in Canada and it costs $399cdn locally (plus 13% sales tax!). I bought mine from Summit Racing for $130usd ($166cdn) !
Works so good I'm getting another one for the Burb.

Off topic...shows you how screwed up our economy is!....please come and annex us and make us the 52nd state!
 
i put a rock auto aluminum tank one in my blazer and it has worked flawless
 
i put a rock auto aluminum tank one in my blazer and it has worked flawless

Part number? Looking at '91 and '84 K5 listings, I only see one copper brass, and it's the 17" core, not the 19".

For a 1984 K20, they don't show/list anything BUT plastic/AL.

Mine does look pretty similar to the CU730, but I'd have to compare the pic to what I have to know for sure...all look pretty similar.
 
yes, sorry should clarify more. there has been a few that have said they used an ebay aluminum before
have you thought about that?
 
I have more faith in my new Spectra than I had in my Griffin, lol.
It is also the diesel, large 2 row, 18x30 IIRC, maybe 19" tall, I don't remember. Fit perfect in the blazer and I even used the older style one piece upper radiator mount.
 
I,ve got the same Spectra radiator, the rows are quite big. I haven't had a problem with
it in 2 years
 
ythere has been a few that have said they used an ebay aluminum before
have you thought about that?

I've got a "Champion" brand AL radiator that will eventually be used to test (it's for a Corvette, much smaller than the stock K5 one, will fit where the AC condenser went), and Dad put a large Champion in his 454 truck. The 454 application has been working fine for years. I didn't like how it fit (none of these things seem to fit the stock mounts/brackets right) but performance-wise it's been great.

Can anyone else with one of these plastic/AL units squeeze their upper radiator hose and see if the tank swells? If the parts-store ones are using poorly made tanks that aren't reinforced very well and swell a lot, that means even the plastic/AL units have different "grades" of quality. :(
 
Not a bad idea, but I'm pretty sure that Schucks (now Oreillys) won't deal with that at all. I can always ask, but I think trying to deal with them on that would be more hassle than it's worth.

If recore costs more than the radiator cost new, pretty easy answer to me.

Guess that was an easy answer...Place I've gone to for decades for radiators/recores is permanently closed. :(

If I could get my hands on a junk AL/plastic, pretty sure they wouldn't care/know the original was copper/brass, and I could give this to someone that has to have copper/brass, or scrap it and at least recoup a few bucks.
I would keep the brass radiator and clean and rod it myself.
It's not that hard and won't cost you much
 
I would keep the brass radiator and clean and rod it myself.
It's not that hard and won't cost you much

It's old enough that I suspect the core tubes are pretty thin in spots. I could be wrong, but that's not a bad idea either. What is used as a tool to rod the core? Special tool, or properly sized piece of brass...?
 
It's old enough that I suspect the core tubes are pretty thin in spots. I could be wrong, but that's not a bad idea either. What is used as a tool to rod the core? Special tool, or properly sized piece of brass...?
A thin piece of steel, you just go gentle with running water on the core surface so water is flushing everything out.
You only need to open one side.
 
Just an update. Ordered a Spectre CU730 radiator and Spectra Premium Heater Core 94553. Both previously made in Canada.
Both now made in China! Ack!
 
Just an update. Ordered a Spectre CU730 radiator and Spectra Premium Heater Core 94553. Both previously made in Canada.
Both now made in China! Ack!

How does the tank "thickness" feel? Is the passenger tank (assuming like mine that there is almost no tank on the drivers side of the radiator) soft enough that you can relatively easily make it give to finger pressure?

I happened to have a buddies OEM(?) plastic/AL radiator from his 1995 K20 in my scrap pile, and I tested the tank "thickness" on it, very scientifical. I can't deflect that thing with finger pressure. The plastic is obviously thicker and better reinforced than the aftermarket I have.
 
Hey D....I'll check tomorrow and let you know.

EDIT: The plastic side tanks do not flex. Seem to be quite strong and thick.
 
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