X25

** TL;DR: Most of this is not news to those who've changed the radiator on this car, before. The two specific issues are cutting down the tab on the passenger side radiator mount, and also 'convincing' the top plastic cover to conform with the tabs on the radiator for best seal. **

The new '19 Z06 A8 cars come with a much thicker radiator. Looks like it was deemed unnecessary for '19 Z06 M7 cars, since they come with AUX radiator, but whoever goes to track with these cars know that there's really no such thing called too much cooling : )

Fitment: Some are wondering if there might be fitment issues with '18 MY owners, due to a difference in the lower left fitting. If you have the issue, the claim is #23171715 is needed.

What you need:

• The new thicker radiator. GM part# 84524653. I sourced it online for $305 + S&H.
• 7, 8, 10, 13 mm sockets.
• A hook-pick to remove one of the coolant lines.
• A large plier (like an
  alligator plier
  alligator plier
  ) to loosen lines.
• Dykes or similar to cut/trim one of the radiator mounts.
• 1 or 2 gallons of DEXCOOL antifreeze and distilled water. You can get it 50/50 mix as well, but I prefer doing my own. Please note, Corvettes DO NOT come 50/50 from factory.

Steps

• Jack the car up, or put it on lift for bottom access. The radiator will not go out from the bottom, but you'll need to drain it and remove one of the lines from the bottom.
• Remove the small plastic bottom cover that covers right under the power steering. Once removed, you'll have access to the bottom of the radiator.

This is the left (driver) side of the bottom of the radiator. There is a small valve on the bottom side of the radiator. You just need to loosen it for the liquid to start leaking. At this time, opening/loosening the cap by the reservoir would also help.

• Remove the shroud, as well as the air intake box.

Shroud is held in place by 4 x 7mm bolts.


You can remove the line to the radiator at the passenger side top to make it easier to remove the air intake.

• Remove the fan.

It's held in place by small plastic slide-on tabs on the radiator, as well as two 10 mm bolts by the sides. Unplug the power cable first for safety, then remove the bolts, and finally detach the cable holders from the fan. Once all done, slide the fan up to remove it.

• Remove all the lines/hoses from the radiator.

You'll need a strong/leveraged plier to make it easy enough for you to remove the big lines. The line by the draining valve is held there by a ring. Just remove it (pictured above) to easily remove the line. The other small line at passenger side top corner is removed by pushing its blue colored locking half-ring half way out.


Here is the radiator with all its lines removed. It's amazing how nicely it covers the front nose opening; good job GM! The A/C condenser is installed on the other side of radiator. Due to direction of those plastic tabs, you'll need to slide radiator under for a few inches to untangle them. This was the most time consuming step for me, since I did not want to hurt the hard A/C lines while jerking it around. I recommend braking the plastic locks of the tabs on the top of the old one, holding the A/C condenser, especially if you'll just dump the original radiator.

• Remove the original radiator, and swap it with the new one.

Here is the new one, temporarily put in place. The original and the new radiators had exact same dimensions except the thickness. At this point, make sure you move the rubber bottom bushings from the old radiator to the new one to reduce vibration on the new radiator. You will need to put the A/C back on the tabs at the back of the radiator. For that, a part of the hard line had clearance issues (see pic below).


This is at the passenger side, by the middle. The plastic support of the radiator's main mount has interfered with the sensor port on the A/C hard line. I cut a small piece of plastic from there with dykes, and also unplugged that sensor during install. Once I did it, putting the condenser back on the back face of the radiator got much simpler (and possible).


Once A/C condenser is on, go ahead and put the main A/C mount screws (13 mm) back on. Once you do so, the top shroud tabs will also start to align. You'll then need to put back the lines.The nut-end of the top shroud's side bolts did not come with the new radiator, so I moved them from the older one.

• Reinstall the fan, intake, and finally the shroud.

The top shroud bolt holes do not have to align, since we now have nuts on the radiator itself, but I still aligned them anyway by pushing the plastic back-shroud in its place for best air seal possible.

• Refill the radiator

My car came from factory with 36% antifreeze. When I drained it, I had about 8 quarts out. I wanted to target 30%, so I used .3x8 = 2.4 quarts of antifreeze, and 5.6 quarts of water to refill. I poured the antifreeze right away, and started pouring the water until it allowed me to do so. You can burp the lines with your hand during this time to let it take more fluid in even before starting the car.


You will need to crank the engine a bit to push the initial air out from the lines. If not, your car will complain about it and throw a few codes. In my case, I just deleted the codes. They will not come back after the first few seconds of engine run. This is also a good time to check for leaks, in case something is not put back right.

• Burping, filling to the line, etc.

There are multiple ways to do this. My way is to just idle it a bit while adding more if it empties the reservoir, and rev it to 2-3K RPMs for about 30 seconds. Once done, I just screwed the cap back, checked for leaks one last time, and went out for a drive. I tried to put some heat during my test drive. Once I'm back home, and engine is cool enough (just below boiling is fine), I opened the cap again, and topped it. It has not dropped from that level since then, during my two days of driving.

• DONE! ENJOY!

--------------------------------------------------

A few fun facts/pics:

The new rad looks about 50% thicker.


15.6 lbs (new) vs. 9.2 lbs (older).



New (left) vs. the older.

Mikec7z

Some of the cars with manual transmissions in the years 17-19 do not have the proper elbow. I will try to get the part number again, but just wanted to throw a warning out to everyone, if you dont have the female elbow pictured below on the concrete, and instead your car has the formed lines pictured in the schematics, you will need the elbow before you do this swap, and its not easy to get.

X25

Edit: It was later deemed that this was wrong information.

Mikec7z

depends on which radiator you have

And frankly, the aux kit will hook into whatever elbow is there, just loosen a hose clamp and swap hoses from the existing elbow.

So its not the aux kit that presents the problem, its swapping from one radiator to the next where things can get messed up

X25

Never said aux rad is the problem, but looking at the schema, it seems to come with what might be needed. To question was to see if the issue is resolved for those with aux rad already installed : )

Anyhow, anyone who's done the install on an older than 2017 MY car, please let us know!

badhabit_wb

Did it on my 2015 with aux radiator. No issues at all. Didn't trim anything on either radiator and had plenty of clearance. Pushed the tabs in on the og radiator to slide the a/c condenser out. Also don't forget the rubber donuts on the old radiator. They have to be removed and placed on the new radiator or you will have problems down the road. One other thing that might help. When I was filling the radiator I left the small top line off until antifreeze started dripping out and then connected it. Saved burping the system and all the codes. It was faster that way too.

Mikec7z

i agree your radiator had the female elbow, not everyone else's will is my point, those with male elbows wont be able to hook into the new 19 auto radiator during the swap. They need the female elbow.

we think it is the 18 cars that will have the elbow issue, but we arent sure if the problem spans other years also.

X25

Cool, I've added a fitment section with this info (that '18 might not fit). If you guys get more info, I'll update it.

I've also added a remark about the bottom bushings to make sure they're not forgotten : )

Mikec7z

i think the 18 will fit, its that it will lack the female elbow fitting on the hose, and they will need to purchase the fitting. Part number is over in other thread.

GM # 23171715

as long as everyone has this elbow, they should be fine is my guess. Some cars already have it, some apparently may not.

cv67

Do you guys know


L x W on either radiator?
Is there a controller or?? From the fan (want to retrofit to older car)CFM?

Pigtail available from fan to?

THanks

BrunoTheMellow

It's a direct fit to a c7 minus the possibility Mike mentions above. It's the same LxW dimensions. Just thicker. About 2 inches thickness.

db2xpert

How much cooling improvement have you seen from this?
Certainly much less expensive than Dewitt or Ron Davis.

So the radiator weighs 6 # more (?), how much additional coolant does it hold?

X25

If it's any indication, I think I put back about half a quart or so more coolant than I drained. If anyone knows the capacity change, please chime in.

I installed this on a '19 Z06, and have not had enough data with the original radiator. That said, I was at a club track day today, and at around 80 degrees ambient and 2300 feet altitude, on a rather technical track, I've hit 280 degrees F oil and 234 degrees F coolant during the session. Not alarming, but not cool, either : )

badhabit_wb

I think I added between a quart and half-gallon more but I didn't measure it.

olblue75

Do you have a pic of the part you cut after cutting it???

badhabit_wb

You don't need to cut anything.

olblue75

This is at the passenger side, by the middle. The plastic support of the radiator's main mount has interfered with the sensor port on the A/C hard line. I cut a small piece of plastic from there with dykes, and also unplugged that sensor during install. Once I did it, putting the condenser back on the back face of the radiator got much simpler (and possible).

BrunoTheMellow

May be a 2019 difference.

Gixxerman

Nice post!

badhabit_wb

I didn't cut anything on my 2015 z06 and it fits fine. On the 19's you'll need to cut just like he did. Not sure why but the valve is closer to the radiator and there's not enough room.