How to keep her cool?

We are the SS vendor who developed and sells the Paradox By Design Cooling System Upgrade kits. There are 50+ members on here with HMMWVs and CUCVs and civilian 6.2/6.5 trucks as well running our kits. The system does not reduce the overall system temperatures much at all as mentioned but you will see less temperature buildup. The overflow issues you are having are likely due to the aeration of the coolant from your water pump cavitating at higher RPMs. Then the rear of the block holding on to the air due to the lack of proper flow, causing steam pockets and localized super heating until the system 'burps' the air and you lose coolant out of the cap. Our system is constantly bleeding the system as you drive. We have even had a situation where a friend installed our kit into a truck with a blown head gasket before he knew about it, then without other good options was able to drive 500 miles home without overheating because the combustion gases were being bled off with our kit. We have a blog article on our website that goes into great detail why our kits work. Take a look.

Drock should get one of those !

911joeblow said:

We are the SS vendor who developed and sells the Paradox By Design Cooling System Upgrade kits. There are 50+ members on here with HMMWVs and CUCVs and civilian 6.2/6.5 trucks as well running our kits. The system does not reduce the overall system temperatures much at all as mentioned but you will see less temperature buildup. The overflow issues you are having are likely due to the aeration of the coolant from your water pump cavitating at higher RPMs. Then the rear of the block holding on to the air due to the lack of proper flow, causing steam pockets and localized super heating until the system 'burps' the air and you lose coolant out of the cap. Our system is constantly bleeding the system as you drive. We have even had a situation where a friend installed our kit into a truck with a blown head gasket before he knew about it, then without other good options was able to drive 500 miles home without overheating because the combustion gases were being bled off with our kit. We have a blog article on our website that goes into great detail why our kits work. Take a look.

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What about the water getting into the oil with the blown head gasket? How does it get that out? That seems like a strong statement to make. False hope to go 500 miles with a blown head gasket. Just saying. Blown engine is right around the corner. Coolant entering the combustion chamber can do major damage at any speed. Water/ coolant hates compression. Just saying. Have a great day. If the head gaskets and heads are cracked they need maintained and changed. Not a bolt on fix.

You are correct, except not all head gasket failures share oil/coolant, also not all head gasket leaks go into the combustion chamber. It all depends on how and where the gaskets/block/head fails. In his case he was venting combustion pressures into the coolant jacket around a failed combustion ring on the gasket. He was over-pressurizing the cooling system and blowing the cap and forcing out coolant there. He thought we was just overheating and installed our system (a very early pre-production version) in hopes to reduce the 'overheating' issue. After spending time in the desert offroading another 4X4 buddy noticed lots of bubbles entering his overflow tank and he called me. I helped him diagnose that it was a head gasket failure. He was in the middle of the desert off road and had few options but to drive it out. With our system he was able to operate without blowing out coolant because of the rapid bleed off with our kit not letting large air pockets to overwhelm the overflow tank. Our system in no way fixes a blown head gasket, nor was I implying that anyone should band-aid their truck with our setup to 'get by' with a blown head gasket or cracked heads etc... sorry for the confusion.

cucvrus said:

What about the water getting into the oil with the blown head gasket? How does it get that out? That seems like a strong statement to make. False hope to go 500 miles with a blown head gasket. Just saying. Blown engine is right around the corner. Coolant entering the combustion chamber can do major damage at any speed. Water/ coolant hates compression. Just saying. Have a great day. If the head gaskets and heads are cracked they need maintained and changed. Not a bolt on fix.

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It routinely gets in the 90's here in Ga during the Summer and my M1008 has never come close to overheating.....

LT67 said:

It routinely gets in the 90's here in Ga during the Summer and my M1008 has never come close to overheating.....

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The closest I’ve ever gotten to even proper operating temps is long extended climbs in the mountains at 60+mph.

Theres certainly something mechanically wrong here.

Update:
So I’m back in Grand Junction. It took the same 5hrs to get back as it did to get to Denver, but I didn’t stop nor did the idiot light for temp come on.
Instead of 32mph in 3rd I did 25-27 in second gear on the steep grades and I didn’t keep it floored everywhere else. She ran great! No issues.
I’ll Check mileage tonight when I fill up, but it appears that at maximum warp I’m always going to get 13.9 - 14.2 mpg.
I ordered the kit from Paradox and have found a 7 bladed fan on fleaBay, so they’ll only help.

Also, should I pick up the 7 bladed fan or this bad boy????
https://www.ebay.com/itm/KKS-3-Rows...m=202201254661&_trksid=p2060778.c100290.m3507


A 4l80e sounds good about now but i’m not convinced the old girl has enough gumption to push the taller gears.
of note, she didn’t burn a drop of oil either way!!!!!!

later

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With that said, I would stick with the regular style fan.
Maintains the character of the truck.

Id stick with the clutch fan, What size fan is the 7 blade you found? Does it look like this one?

Tinstar said:

You cannot post a link to an active listing.

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Doh! Thanks Tinstar

ken said:

Id stick with the clutch fan, What size fan is the 7 blade you found? Does it look like this one? View attachment 730163

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It sure does. I won’t post a link to it but it’s the only 6.2L fan clutch on fleaBay currently.

Hmmm I wonder if cucvrus has any laying around. I’d rather give my money to someone “known” here.

I didn’t realize you were in Grand Junction. I’m in Denver. Going up i70 I’ve only ever been to Georgetown but can’t say I’ve overheated, I’ve had my gauge read about 200 though on the longer climbs. One of these days I’ll test it out heading over vail pass.

Yeah, I was going to reach out to you and see if we could meet up, but my second born man-child was graduating high school and it was a hectic time.
I’d love to get a gathering of Colorado CUCV’s for a off road weekend.

Update:
Paradox kit installed. 7 bladed fan from a Suburban 6.2L on the way. Ordered 4 row rad from Performance Radiator.
I’ll install them both when they arrive.

Also, cucvrus the radiator looked a bit worse for wear once I removed the top cover and shroud for a better look at it.

Thanks all all for the advice.

Put in New radiator insulator bushings while you have it out. And while you have the radiator out, it's a good time to put in a front main seal if yours is leaking and inspect the harmonic balancer for its condition. It's also about the only time you'll have to sand any rusty spots under the radiator and repaint them.[HR][/HR]

Will do, thanks

Rustyshackelford said:

I installed a new genesis radiator, Hayden 2799 clutch, derale 17120 fan, high flow 185 degree thermostat, and a kit from this thread. I have 456 gears and live in 110degree heat. It never gets above 190.

https://www.steelsoldiers.com/showthread.php?167433-CUCV-Cooling-System-Upgrade-Kit

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I installed the same cooling retrofit as Rusty on my 1009. Difference is my 373 gears ( 1 Tons ) and Banks Turbo.
Before retrofit I was sometimes charting 205-220 on the temp gauge with stock 308 gears and 3/4 ton axles, ~ 2350 rpm while climbing from 2600 to 3600 in 10 miles and depressed at the idiot light looking at me.

After retrofit unit rarely gets above 195. I primarily run in the AZ flatland desert heat.
Biggest single heat temp remediation with the 308's was slowing down. ( 373's took care of that indiscretion) Second biggest heat temp remediation was the aluminum radiator. I am clearly not a CUCV purist.

Update:
so I’ve Learned a lot about radiators. Turns out they have quit doing 4 row (core) radiators since they came out with a high efficiency 3 row design that uses smaller fines and tubing. I’m told these are the new wave rads. Anything that was 3 rows gets 2 now, yada yada yada.....
So I was already to install the new brass and copper rad when I spotted this.... bolt pattern on the 7 blade is larger. 2 1/8 center to center on the 5 blade and 2 1/2 on the 7 blade



Any my thoughts or hacks to make this bad boy work and not eventually detonate my water pump?

thanks

I'd just as soon roll with the original at this point. Between the new radiator and coolant bypass, I'd wager you'll not have too much trouble overheating anymore anyhow. I doubt you'd be able to get it perfectly centered anyway.

You will need a HAYDEN Part Number 2828 fan clutch. The one you have is for a C60 2 ton Chevy.