DIY Cornerstone Radiator Replacement

[Cruzer]

Our 2016 Cornerstone developed the typical leak common to radiators used by Spartan around that time. At 4 years old Spartan didn't honor any warranty on the radiator so I had to buy the radiator and do the installation myself to save the high cost of labor.

The original radiator design was known for failures and Spartan has since switched over to a new manufacturer with a better quality radiator. The radiators are not identical so Spartan offers an upfit kit which includes the brackets and hardware necessary to perform the replacement. The part number of the retrofit kit for the K3 chassis is S-2676-001 and cost me $2,544.42 after shipping. The documents that come with the kit indicate that their is also an upfit kit for the Anthem and Aspire's K2 chassis and it looks like that's an S-2675-001, which costs less but I don't have the actual price of that kit. The replacement procedure is basically identical between the two but the main difference is that the K3 radiator is about 40% larger than the K2 - 1,891 sq. in. versus 1,363 sq in. While the procedure is virtually identical I found that the massive size of the K3 radiator made me really wish I had an Anthem instead of a Cornerstone because the extra size made the installation more difficult.

Removing the old radiator was fairly easy. I began by removing the rock guard from beneath the radiator. Then I unbolted the spider that holds the fan drive to the radiator frame and supported its weight via some nylon straps. Then the fan blade was removed and the fan shroud. Ten self-drilling hex head screws (5 on each side) were then removed that held the charge air cooler to thr radiator. That exposed the mounting for the radiator and after removing and loosening everything the old radiator was ready to slide out while the CAC remained in the mounting frame.

Unfortunately the leveling jacks (with Snap Pads) could not raise the coach high enough to clear the additional height of the K3 radiator to get it out from beneath the coach so I had to add about 4" of blocking beneath the rear jacks. Once up, a a pair of heavy duty jack stands was used as a safety precaution.

The original radiator was 100% aluminum. The side tanks were folded and welded rectangular tanks with welded ends that the aluminum core was pressed into. The new Modine radiator had a brass core but the tanks were a much thicker cast aluminum instead of the thinner tanks on the old radiator. If anyone wonders which radiator their coach came with it will be easy to tell by looking at the side tanks. The old leaky radiators have square thin-wall tanks while the newer Modine radiator has cast tanks that are rounded. I've attached photos of the two radiators for reference.

Installing the new style radiator required a different mounting method so the included brackets were installed first. This required chiseling off a pair of unused nutserts and drilling some holes to mount the new vertical adapter rails. A bracket was installed to support the bottom of the CAC and the radiator was ready to slide into place. So far, not so bad.

The real headache began when it was time to install the fan shroud. The fan shroud bolts to the frame (which has captive nuts in place) via a ten 5/16" USS bolts with a 1/2" hex head - five at the top and five at the bottom. The problem is that these bolts are installed inside the shroud, not on an outside flange. Not bad on a K2 chassis but the additional height of the K3 radiator and shroud made it impossible to reach up inside the shroud to the top row of bolts, let alone support the shroud to line the holes up. I wound up fiddling around with a floor jack to support the shroud and try to get the holes to line up just right. But there was no way I could reach the top row. I wound up using a cordless ratchet with some electrical tape in the socket to hold the bolt while I reached up to try to align it with the hole. Of course it typically took about ten tries per bolt with the bolt falling out of the socket or me bumping the shroud enough so that it had to be realigned again. After that daunting task the rest of it came together pretty good.

All in all it took me about 10 hours without any help, although Leann did help me operate the floor jack while I guided the new radiator up into the rails from the back side - which I would never have been able to do by myself. I saved quite a bit of labor (my local truck garage charges $155 per hour) but it was work and I did have the tools that I needed. Everything turned out fine and we're now leak-free.

[Gary.Jones]

As usual Mark.... thank you for the excellent write-up. It is clear that this was a daunting job for you and LeAnn and my hats off to you for giving it a go. My hat is off even more for you taking the time to add your knowledge and experience to the knowledge-base of this forum for those that follow your lead and tackle this on their own.

I continue to wonder why this has not been considered a class action manufacturing defect that would generate a class-action lawsuit brought by owners against the chassis manufacturer who then would, I'm sure, turn around and bring suit against the manufacturer. The radiator problem should be recognized as a manufacturing defect and liability which continues well beyond the chassis warranty. Why hasn't this been defined as a manufacturing defect? Does anyone know? Maybe a lawyer-owner has some insight.

Again, thanks for the nice write up. I think my radiator is a Modine radiator on this new coach and I hope that it holds up very well over time. The pix you included appears to show a massive difference in the sturdiness of the Modine radiator side tanks compared to the original construction.

Gary

[Nowabeachbum]

As always, a great write up Mark! I’m glad everything went ok and I hope I never have to do it!

[jrugarber]

Thanx Mark for the information... great write-up and pictures. I will begin to save my pennies for the eventual repair I'll need, as it looks as though I have the old style radiator. I'll try to be an optimist, and hope that it doesn't occur.

[oneknight]

Originally Posted by jrugarber

Thanx Mark for the information... great write-up and pictures. I will begin to save my pennies for the eventual repair I'll need, as it looks as though I have the old style radiator. I'll try to be an optimist, and hope that it doesn't occur.

Check your dates and start working that!
Spartan's warrantee is 3 years. Mine is an early 2017, and I did get it replaced under warranty. I first became aware there could be a leak in October, 2018. Verified leakage and notified Spartan in July '19, weeks before the warrantee would expire, and actually had the work done months later.
My leak was teensy tiny, and they gave me no problem.
They generally leak when cooling down, and often don't leave much of a puddle.
Spartan is looking for a darkening of the fins in the corners, from the fan side. Maybe crawl under there with a good light and take a peek?

[photraveller]

Mark, great write-up.

Your pictures confirm that our late 2017 build coach still has the old radiator.
So I feel like we living on borrowed time with our Aspire.

Even with the Aspire's smaller radiator, this write-up reminds me that I'm not going to attempt this repair on my own , when my number comes up.

Spartan is probably the only one who know what percentage of these radiators are failing. But it sure does seem like it's high enough percentage that there should have been a recall or at least an extended warranty.

Then again, I argued with Spartan a year ago about my expansion tank looking rusted to no avail. Only to have it rust through this past spring less than 3,000 miles later.

Steve

[RubiconTrail]

Nice writeup, Mark. Up to your usual standard, of course! I have the tools and knowledge too, but my motivation is lacking .

My 2017 is coming up on end of warranty in January, time for me to get under and look. Thanks for the reminder.

John

[Jim_HiTek]

@Cruzer, any chance you're planning on something like going to the factory and parking across the street with a big lemon on the side of your rig? Or to the local court and initiating a claim in small claims court?

That seems soooo wrong that they are getting $2500 to replace their defective rad.

[Matt D]

Please note Mark lives in Wisconsin, and enjoys the fresh air when he works!

I think the weather takes this to another level of pain.

Well done Mark!

-Matt

[Cruzer]

Originally Posted by Jim_HiTek

@Cruzer, any chance you're planning on something like going to the factory and parking across the street with a big lemon on the side of your rig? Or to the local court and initiating a claim in small claims court?

That seems soooo wrong that they are getting $2500 to replace their defective rad.

It's disappointing that a known issue exists but I am one year out of warranty and that's generally the way things go sometimes so Spartan isn't that far off of most manufacturers. Both Spartan and Entegra have treated me well in the past and, except for this radiator issue, I love my chassis don't think putting up a big fuss would accomplish anything or be the right thing to do. It's not like these things are sold with a forever warranty and had it occurred a year earlier I'm sure they would have taken care of it.

[Cruzer]

Originally Posted by RubiconTrail

Nice writeup, Mark. Up to your usual standard, of course! I have the tools and knowledge too, but my motivation is lacking .

My 2017 is coming up on end of warranty in January, time for me to get under and look. Thanks for the reminder.

John

Yeah, I figure that with roughly $1,500 in labor I could always save that money and buy any more tools that I might need to finish the job. After all, you can never have too many tools.

You can probably see the leak once it starts., Mine was visible at the lower right corner and was visible from the outside and was easier to see through the grill louvers on the K3 chassis than on the inside. After a good run shut it down and wait for it to cool and contract and you will see the leak - if it is there.

[jth camper]

Thanks Mark, I've got a2019 and I really hope I do not have that problem. But should I do you made it a lot easier or piece of mind to not stress over the failure. Thanks again.

[DavidH2]

Originally Posted by Cruzer

Yeah, I figure that with roughly $1,500 in labor I could always save that money and buy any more tools that I might need to finish the job. After all, you can never have too many tools.



You can probably see the leak once it starts., Mine was visible at the lower right corner and was visible from the outside and was easier to see through the grill louvers on the K3 chassis than on the inside. After a good run shut it down and wait for it to cool and contract and you will see the leak - if it is there.

Mark- I just discovered the same issue yesterday morning when I was prepping to depart Lake Charles, La. for home. My 16 CS has only 25600 miles on it. Spartan is saying they will sell me the part/kit for $2000 as I am at 3 yrs and 11 months. Is that consistent?

Not sure what level of mileage most are discovering this problem, but it clearly seems to be a manufacturing defect. I would love to start a chart of how many have had this problem and at what age and mileage.

[Jim_HiTek]

Failure at 25.6K miles is ridiculous in my mind. Rads are typically designed for 100's of thousands, not thousands of miles. I know if it were my rig, I would definitely avoid the manufacturers replacement. You often don't know if you're going to get an 'improved' version or if they have the old types still sitting on the shelf. I've priced out my big giant diesel pusher rad before and it was only $450-$850 or so depending on manufacturer, not $2K so I wonder about that pricing too.

I would recommend anyone that has to deal with this Spartan leaking rad issue to contact the FTC and just file a complaint. They made it easy with forms online. Might not help you but sometime down the road, it could perhaps help others if the rads are recalled. If it becomes a DIY project, keep track of your time and materials just in case.