Zombie Slayer: Champion Radiator Install

UMR_Engnr

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This all started when I noticed my radiator cap was leaking. I replaced it, topped it up the fluid, and then went about my business thinking I had done something good. The next day I noticed antifreeze pouring down my driveway after the drive home from work. Disappointing, especially since I had just fixed my frozen front caliper and was able to drive it again. It looked like it was leaking from the seam below the top reservoir, and that it wouldn't be worth repairing. After some research, I ended up purchasing a Champion MC1165 4-core aluminum radiator.

Upon first inspection the radiator looked pretty good. The welds were solid and nothing was damaged. It comes with some trans cooler fittings, a cheap radiator cap, and a petcock installed.

The trans cooler fittings were the first hiccup. The radiator comes with some flared fittings welded to the bottom reservoir, and then they include a flared hose fitting and nut. The included hose fitting was too large for my trans cooler hose (looked like it was for 3/8" hose). I called Champion to see if they had a different size or could tell me what size fitting it is so that I could buy an adapter. Unfortunately, the guy on the phone didn't have much information. He figured the bigger fitting was for a later model that used the same radiator, and they didn't have smaller hose fittings. He gave me the thread size for the fitting but after I checked it out more on my own, what he told me was incorrect. If I remember correctly, the fitting turned out to be an M14x1.25 with a 45deg flare. This doesn't match either AN or SAE spec, and I was unable to find any flared nut that will fit that size fitting. The guy on the phone suggested just using a barbed fitting to reduce it. I like making things look professional and that just didn't sit right with me. So this is what I came up with.

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I took a 3/8" nickel copper brake line and did a 45deg single flare and then cut it off as close to the flare as possible. Then I took a 5/16" nickel copper brake line, and did the first step of a double flare to create a bubble. I then cut the 5/16" to match the original fitting length. After some sanding and polishing I got everything fitting well and soldered it together. I used regular plumbers solder because it is rated up to 430degF which seemed like plenty. I reused the nut from the old fitting since I couldn't find anything like it.

The radiator core supports on our trucks have two posts on either side of the radiator. You slide the radiator onto the post and then bolt it to the front of the core support. The radiator has rubber isolators that fit on the posts. Unfortunately, on the Champion, they just made a big pocket for the isolator to go in, but it is much to big. It looked like the posts would end up riding on the aluminum and not the rubber. To fix this I cut a 1/4" HDPE cutting board into a strip. The strip fits perfectly between the top of the pocket and the bottom lip of the radiator reservoir. Once the isolator is installed it can't come out and everything fits snug. I had to shave the rubber ears off the isolator with a razor blade, and used some sil-glyde to make it slide in easier.

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The final major hurdle was with the fan shroud. The mounting holes did not line up. I don't know if trucks have different fan shrouds, or if this is just poor design. Maybe they want you to drill new holes? I don't know. Anyways, it was offset such that the hole would have ended up on an angled surface so I scuffed up the surface, mixed up some JB weld, and created a new surface for the bolt to go through. I checked my old radiator versus my new radiator to determine which hole was off, so that I could ensure the fan shroud would remain with proper clearance around the fan. The bottom hole was the one that was not correct. I am glad that I did this out of the truck, because I would have been ticked if I got the radiator in only to find out that the shroud wouldn't bolt on.

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Other than that, I wanted to make sure everything else was installed correctly on the radiator before I installed it. The included petcock had a rubber seal and no tube for a hose to fit over (for coolant drainage control) which I didn't like, and so I got one with a metal to metal seal and a tube, and installed it with thread sealant. There is another port on the radiator for the e4od I believe but I don't know its purpose. I removed the plug. It has straight threads and an o-ring. I cleaned the threads, lubed the o-ring, and re-installed. It doesn't seem very secure. Maybe I'm being paranoid, but I'd hate for it to vibrate loose while I'm going down the highway. I also replaced the included cap with a Stant one, and cleaned and re-sealed the tube fitting for the coolant overflow reservoir.

After all the prep work the install went easy. The aluminum radiator is much lighter than the original and I was able to lift it in myself pretty easy. The radiator sat well in the posts, on the rubber and nice and solid. Then it was secured to the radiator core support with the four bolts. The trans cooler lines and coolant lines were connected, and then the fan shroud was bolted on.

I filled the radiator with distilled water using a Lisle 24680 Spill-Free Funnel (which worked awesome) and let it run until the thermostat opened and I could get all the bubbles out. I then let it cool, drained the coolant, and refilled with more distilled water. (Definitely get a hose to put over the end of your radiator petcock, it makes the job much cleaner. With some petroleum jelly on the petcock the hose slid right over and I could turn the petcock while I had the hose in my catch pan.) I think it took me three cycles with distilled water until it came out clear. Then I drained out 4 gallons, and topped it up with 4 gallons of FleetCharge. I ran it for a while to let it mix, and now I'm good to go. I haven't put too many miles on it yet, but so far so good. I'll update this post if things change down the road.

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Overall, for ~$300 the radiator was a good value, but it was definitely not a drop in replacement. It would be awesome if they put the fan shroud mounting holes in the right spot, made sure the pockets actually functioned with the stock isolators (or included ones that work), and changed the trans cooler fittings to AN-6 so that any number of hose adapters could be sourced. I'd much rather they make those changes and leave of the petcock and radiator cap.
 
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reklund

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Nice write up. Hope it provides years of good service. I talked with the boys at Griffin radiator at SEMA about making a good aluminum radiator for these old trucks. They will custom make anything, but it won't be cheap. Sounds like this is a nice compromise.
 

UMR_Engnr

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What is it about old/dirty coolant that affects aluminum radiators? I have a coolant filter I'm going to install so I'm not worried but am curious. When looking for a replacement radiator I did not see many options. Is there a better option out there? Most replacements seem to be metal with plastic reservoirs and those didn't seem as durable as a welded aluminum one.
 

79jasper

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He's not saying the all aluminum ones are bad, he's saying keep up with your coolant maintenance.
Stock for these trucks is brass.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

UMR_Engnr

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Is the issue particles in the fluid wearing down the aluminum because it is a soft metal or something else?
 

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