I was going to add this to my build page, but I felt like it might be useful as a stand alone so here it is. @JDM Journeys this is for you!
I’ve been struggling with heat management in my turbo charged HZJ77 automatic as of late. Now to be fair, I have added a roof rack and larger tires, but I also regeared to 4.56. It’s on 295/70/17s now. But the long story short is I live in denver and have started heading into the mountains more in the summer, which has left me on the side of the road revving the engine trying to bring water temps back down.
Things I replaced: thermostat, hoses, water pump (was done 20k km ago) I guess that’s it for normal changes
Upgrades I added: PDI FMIC, quikazz fan+coupler.
The most recent change with the fan seemed to help a bit (can definitely hear more air) but it was also 7-10deg ambient temp cooler on my drive than the last time. I still had one more item I wanted to change: the radiator.
I still had my original radiator, but currently I have been running a China aluminum radiator.
I swapped that one in while living in Texas to help with cooling. I don’t remember a noticeable change back when I did it.
Now I’m sure many know the HDJ radiator is 60mm longer and thus has more cooling ability. Some members have posted that it cured their cooling issues. That set my target, a 560mm long radiator for the 77.
So as I saw it, I had 3 options:
- Get the original radiator re cored, add 60mm.
This estimate was 700+ and honestly made me hesitant. Everyone online says their material is better for a radiator, but I don’t care about an aluminum and plastic tank radiators “potential” lack of durability. I want peak engineering prowess for cooling.
- replace with hzj76 narrow nose radiator (16400-17300).
I would hope that this would out perform the original radiator and the China radiator, most vehicles with issues (non 70) in cooling see a noticeable improvement with an OE radiator.
- purchase an HD radiator and install(16400-17360)
This would get me a longer core, and a more updated radiator design (plastic and aluminum). The issue here is this radiator was never available in NA so I’d have to buy and get it shipped which was looking like 700+ as well (and hoping no damage)
Thankfully I have some access to parts info for Toyota, so my search began on another option as my goal of 16400-17300 radiator were dashed when I found that it was no longer being ordered to restock our dealers in the states. Maybe Canada could get it but I couldn’t.
After searching pictures and part numbers I found that a 2007+ HZx radiator was actually the same size core as an HDJ radiator. And more importantly, there was stock in North America
. The part number is 16400-17401, and the core measures 560mm long. It’s also about 15mm wider and a few mil thicker than my aluminum radiator. Score.
So I had to go through an approval process that required an HS7 form for the parts as this is technically for a vehicle not legal here. But approval happened in a day and the order was shipped to my local dealer. I may add that process in here. Canada you may not need any extra process, I did confirm there is plenty of stock of these in your parts houses.
The parts I ordered are:
16400-17401- radiator
16711- 17151 - shroud
16572-17150 - lower hose (it’s 40mm at the radiator end instead of 38mm and longer)
I could have ordered an over flow bottle and bracket to make things fit better, but they fit good enough that I don’t feel the need to get those as of now.
I’ll explain my install process here in a bit but I want to share two other options for fitment, and that’s the radiator plates. don’t know if they are an exact fit, but the HDJ side plated are still available via monotaro in Japan. You need to find a friend to order and ship them, but I would think they are substantially similar to the core I have now and would be a simple install.
The other option is for the Canada boys, I would guess there are some wrecked or damaged narrow nose, plastic tank vehicles available. You could snag the side plates off, extend the bottom 60mm and be of and running. Again, untested but it’s gotta be in the hunt.
Now I’m cheap and don’t live in Canada so I modified the backets. It took some time, but I got It all done in about 2 evenings so not bad!
First up, some pictures.
As you can see, more columns, and longer!
I took alot of measurements to try and get an idea of where this should all fit, especially with how high the cap should be. Those measurements got my first setup in the hunt when test fitting, and then I used the fan blade gap on the shroud to help center it height wise as best I could. Happy to say it only took 2 tries.
First step was drilling out all the spot welds to start with a clean plate.
I’ve been struggling with heat management in my turbo charged HZJ77 automatic as of late. Now to be fair, I have added a roof rack and larger tires, but I also regeared to 4.56. It’s on 295/70/17s now. But the long story short is I live in denver and have started heading into the mountains more in the summer, which has left me on the side of the road revving the engine trying to bring water temps back down.
Things I replaced: thermostat, hoses, water pump (was done 20k km ago) I guess that’s it for normal changes
Upgrades I added: PDI FMIC, quikazz fan+coupler.
The most recent change with the fan seemed to help a bit (can definitely hear more air) but it was also 7-10deg ambient temp cooler on my drive than the last time. I still had one more item I wanted to change: the radiator.
I still had my original radiator, but currently I have been running a China aluminum radiator.
I swapped that one in while living in Texas to help with cooling. I don’t remember a noticeable change back when I did it.
Now I’m sure many know the HDJ radiator is 60mm longer and thus has more cooling ability. Some members have posted that it cured their cooling issues. That set my target, a 560mm long radiator for the 77.
So as I saw it, I had 3 options:
- Get the original radiator re cored, add 60mm.
This estimate was 700+ and honestly made me hesitant. Everyone online says their material is better for a radiator, but I don’t care about an aluminum and plastic tank radiators “potential” lack of durability. I want peak engineering prowess for cooling.
- replace with hzj76 narrow nose radiator (16400-17300).
I would hope that this would out perform the original radiator and the China radiator, most vehicles with issues (non 70) in cooling see a noticeable improvement with an OE radiator.
- purchase an HD radiator and install(16400-17360)
This would get me a longer core, and a more updated radiator design (plastic and aluminum). The issue here is this radiator was never available in NA so I’d have to buy and get it shipped which was looking like 700+ as well (and hoping no damage)
Thankfully I have some access to parts info for Toyota, so my search began on another option as my goal of 16400-17300 radiator were dashed when I found that it was no longer being ordered to restock our dealers in the states. Maybe Canada could get it but I couldn’t.
After searching pictures and part numbers I found that a 2007+ HZx radiator was actually the same size core as an HDJ radiator. And more importantly, there was stock in North America

So I had to go through an approval process that required an HS7 form for the parts as this is technically for a vehicle not legal here. But approval happened in a day and the order was shipped to my local dealer. I may add that process in here. Canada you may not need any extra process, I did confirm there is plenty of stock of these in your parts houses.
The parts I ordered are:
16400-17401- radiator
16711- 17151 - shroud
16572-17150 - lower hose (it’s 40mm at the radiator end instead of 38mm and longer)
I could have ordered an over flow bottle and bracket to make things fit better, but they fit good enough that I don’t feel the need to get those as of now.
I’ll explain my install process here in a bit but I want to share two other options for fitment, and that’s the radiator plates. don’t know if they are an exact fit, but the HDJ side plated are still available via monotaro in Japan. You need to find a friend to order and ship them, but I would think they are substantially similar to the core I have now and would be a simple install.
The other option is for the Canada boys, I would guess there are some wrecked or damaged narrow nose, plastic tank vehicles available. You could snag the side plates off, extend the bottom 60mm and be of and running. Again, untested but it’s gotta be in the hunt.
Now I’m cheap and don’t live in Canada so I modified the backets. It took some time, but I got It all done in about 2 evenings so not bad!
First up, some pictures.
As you can see, more columns, and longer!
I took alot of measurements to try and get an idea of where this should all fit, especially with how high the cap should be. Those measurements got my first setup in the hunt when test fitting, and then I used the fan blade gap on the shroud to help center it height wise as best I could. Happy to say it only took 2 tries.
First step was drilling out all the spot welds to start with a clean plate.