Install of the CSF All-Aluminum High-Performance Radiator

I have a 2020 off-road premium that my wife and I almost always travel with our 5x8 off-road trailer attached. Our son lives in Colorado and we are often pulling our trailer through the Rocky mountains. So I felt it would be a good idea to beef up my engine and transmission cooling. After some research, I found a nice link that described the CSF radiator and how to install it. That link can be found at:

https://trail4runner.com/2020/06/03/csf-high-performance-radiator-install-review-5th-gen-4runner/

After reviewing the link I felt this would be a good upgrade, so I ordered my CSF Radiator from Pure Auto Parts. Total cost with tax and shipping was $529.99. It arrived in 3 days and was well packaged. There were no instructions included, as I am certain they feel you know what you are doing if you are ordering a new radiator. Below I describe my install and provide you with some lessons learned along the way.

Prior to taking any parts off, I reviewed the link above multiple times and made the effort to identify all the components involved before embarking. Once confident I knew what to do I started on the replacement. I will reference the step numbers that were provided in the link above, as part of that authors write up.

Steps 1-6 These were very straight forward and the work is easy, so nothing to mention about these steps other than my hoses are like new, so I did not have to replace the hoses connected to the radiator, but only had to disconnect them from the radiator.

To make the steps above easier, I recommend purchasing the hose clamps listed below from Amazon. I used the two smaller clamps from the set to clamp-off the transmission fluid lines at the bottom of the radiator.

https://www.amazon.com/gp/product/B01CRKCF3U?ie=UTF8

Also, here is a tip for removing those transmission line spring clamps. Use a pair of vise grips to initially open the clamp. Then use a small pair of channel locks to tighten the vise grips with screw knob to continue to open the clamp to its full width. This will ensure you are not struggling trying to keep a clamp open, while attempting to disconnect the line from a difficult spot. When you go to put those clamps back on, repeat the process. One of the best uses of vise grips I have ever found.




Step 7 Removing the transmission line mount from the fan shroud was easy. However, I will describe later the difficulty with getting it back on and what I did to solve it.

Step 8 This step was a sticking point. The author, in his post, says to remove the fan shroud. There was no way to remove the fan shroud, as it could not get past the fan blades. I ended up purchasing an online Toyota tech manual for my 2020 4R. The steps listed for removing the fan shroud require that the fan mounting bracket be removed. Note, this is not just removing the fan impellers, which is good as that would require removing 6 bolts from a difficult place. It is removing the green bracket that attaches the whole fan assembly to the serpentine belt pulley. This was not difficult, as the 4 nuts can be fairly easily reached. I did note which hole of the fan assembly had what appeared to be a balancing mark, so that I was sure to put the bracket back on the pulley mount in the same configuration.




Step 9 This step is straight forward and I went ahead and removed the whole front bumper to ease the installation process. Removing the front bumper is not hard at all. There are a few YouTube videos for how to do this.

The top two bolts are easily found on the backside of the radiator on the mounting rails. You will be removing the mounting rails, along with the radiator.

The lower two bolts are on the front side of the radiator and little more difficult to locate. The author's instructions are not crystal clear where the lower radiator mounting bolts are, so I have provided pictures below to help you locate them.

In the picture below the arrows are pointing to two plastic pieces that are snapped in and easily detached by pulling outward and toward the center. These will fold in and expose access to the the lower bolt on each side.




Here is pic of the lower mounting bolt on the left side (passenger side). The hole is where the plastic piece plugs into. The right side is just the same, but in reverse.




Once you haver removed the 4 radiator mount bolts you can lift out the radiator, along with the mounting brackets. The CSF radiator has welded on brackets, so there i no need to remove the mounting rails from the old radiator. You will need the four bolts you removed.

Step 10 Do as the author instructs. With regard to reattaching the transmission lines to the fan shroud, here is what I did since mounting that screw is tough. This is due to the limited hand space and the fact that you are mounting the screw toward you. I put some paper towel in my socket so the screw head would not fall out. I attached a 3 inch ratchet extension and used my hand to get the screw started. Once it was securely in the threads, I could tighten with the ratchet handle. Getting the bracket aligned with the hole is a challenge due to the tight working space.

Step 11 I skipped this step as I could find no reason for adding the foam strip. The foam is about 1/2" thick and the gap from the bottom of the radiator to the frame rail is an inch or more. Additionally, my 4R has a big piece of foam in the front of that gap which is about 2 inches thick and easily fills the gap from the frame to the radiator. So I skipped the small piece of foam which I don't think would last anyway.

Step 12 Starting with this step, I recommend having a helper. There are some alignment steps with mounting the new radiator which requires a person working from the top and one person underneath.

It is critical as you lower the radiator such that the transmission lines, which were detached from the fan shroud, are not preventing the fan shroud bracket from being in the correct spot. I failed to do this and as a result could not reattach the transmission hoses at the bottom of the radiator. While I and a friend mounted the radiator, I was on my own when I discovered this problem and had to detach the radiator to correct the issue and reattach the radiator. Fortunately I did not have to lift the radiator up, which would have freed it from the bottom alignment tabs. If I had detached it from the lower alignment tabs, I would have needed another helper again.

It is these bottom alignment tabs that make it necessary to have two people install the radiator. My friend worked from above and I made sure the bottom of the radiator properly seated into the bottom mounting tabs. This would be a challenge by yourself.

The author of the post I reference has a good picture of the lower mounting tabs.

The last steps require reattaching all your hoses and brackets. Remember to use my vise grip technique for getting all those hoses back on. Especially the transmission lines at the bottom the radiator. There is little working room to attempt to open the clamp with pliers, while trying to thread it on to the hose.

I will forgo the steps for filling and burping a radiator, but I did buy all new radiator fluid just so there was no contamination from reusing the old fluid. I purged the air from the radiator for 25 minutes. I do recommend using a radiator burping funnel. I also checked the transmission fluid level and added as necessary, since the new radiator may hold more, and a small amount was lost from the original radiator, once the lines were removed.

This is not a terribly difficult job, but is tedious as you are often having to get your hands and tools in confined areas.

Here is pic of the finished install while the bumper and cover plates were still off, and I had not yet cleaned the front side of the A/C coil.




The author of the original post provides some useful photos as well.

I hope you find this helpful, should you decide to perform this upgrade.

You can see my full build page at the link below.

https://www.4runners.com/threads/cowboys-first-4runner-and-chronicle-of-mods-upgrades.18688/

 

The lower section of the radiator is the transmission oil cooler on a 4Runner. The upgraded radiator should cool the transmission fluid more efficiently. I pull a small 5x8 overland trailer. After the swap, I checked the transmission fluid levels according the Toyota service manual, which requires checking the fluid at a certain temp. Prior to checking the fluid levels, I added about a half a quart of transmission fluid. When checking the levels, all but about a 1/4 to a 1/3 of a cup came out. That amount is likely the amount I lost doing the radiator swap. I have yet to take an extended drive with the trailer, to know if the transmission temps are running any lower, than prior to the swap. I suspect they will be somewhat lower. But in either case, the new radiator should cool the fluids more efficiently.

 

All the factory hoses went right back on. I recommend having a friend help with taking the fan blade assembly off and back on, as a third set of hands is necessary to assist with managing bolts and holding it in place. Be sure to use a black marker to mark the orientation of it as well. The other place a third set of hands was useful was in remounting a wire or hose hanger on the left side of engine when facing the radiator. Also, the install will go easier if you remove the front bumper.

 

Wow I came across this bc it is getting hotter and hotter in texas and was considering upgrading my radiator...I can't believe not many people posted here. Great write up!

How is it holding up after a few years?

 

It has worked flawlessly. I have not had one issue since the install and temps have been great, even when pulling my trailer.

 

Wicked. I had a CSF in my Titan and loved it. I have been contemplating one in my 4Runner.

 

Any before and after temps to showed how much better it did?

 

No leaks? I had seen on one of the forums that they started leaking.

 

Mine leaked on day one. All that time and money putting it in. 4Runnerlifestyle was a pain in the butt about returning it. Would never buy one again. Nominal improvement at best, huge time wasted, and obviously CSF doesn’t pressure test their units. Read other forums. These leak like sieves!!!

 

If I was going aftermarket I’d separate the radiator and trans coolers. A quick and easy way to destroy a transmission is to have the coolant and trans fluid mix in an internally leaking cooler.

 

Regarding that some have reported leaks, one time I checked the level of fluid in the radiator. Everything looked great and I added some to the plastic reservoir. Took the 4R to town and came home. A couple of days later I noticed some radiator fluid drops that looked as though the radiator was leaking. I started the 4R to see if there were any leaks. I ran the engine for about a minute and I did not see any leaks. I opened the radiator cap and the radiator was full. I put the cap back on stated the 4R and was letting it run when I noticed a very small amount coming out the cap. What had happened is that I thought the cap was on tight, but I had not pressed down the cap and twisted further to fully seat it. When you close the cap on the radiator it is easy to think you have fully tightened it when you haven't really done so. I have to wonder if some may think they have a leak when they do not. I have driven my 4R several times this summer in the heat of Florida and still have had no leaks since completely tightening the cap.

 

Glad yours is working well. Mine leaked from the core in 20 places, sadly not at the cap. Cost me a huge amount of time. Zero of those should ever leak as each is supposedly pressure tested and yet many many leak. Other forums have tons of stores of CSF quality problems. I am glad you got a good one. I still wouldn’t recommend until they can do the product as promised with consistency.