NSX NA1 How to Replace the Radiator

Considering the model year, I replaced the genuine radiator, which can burst at any time, with an external product. By the way, all the coolant is replaced.

First, open the drain cock at the bottom of the radiator and drain the coolant. Jack up left and right, and hang the rigid rack only on the rear side so that the front side goes down. While removing the coolant, remove the bracket on the top of the radiator and the relay-related connector of the electric fan. When the coolant is almost drained, remove the upper hose and lower hose, and pull out the radiator directly above.

Completed removal of genuine radiator.

The radiator to be installed this time is TYPE-F made by KOYO. The capacity is increased to 48 mm compared to the genuine thickness of 32 mm. Dry weight is about 4.25 kg. It ’s all aluminum, so it ’s very light. The weight of the genuine radiator is about 4.02kg, so it is a little heavier.

I’m moving the electric fan to a new radiator, but the fan shroud and the hose attachment part interfere a little, so I cut out that amount.

After assembling the electric fan, install it on the vehicle side in the reverse order of removing the radiator. There will be a slight gap before and after the radiator, so stick a seal to prevent the running wind and fan wind from escaping as much as possible to close the gap. I think it will be a little effective. Make sure that you have not forgotten to connect the pipes, connectors, etc., and add new coolant.

Uses HKS racing coolant. I’m used to normal green, so this yellow feels a little strange. The operating temperature is from -18 ℃. The freezing temperature is inferior to that of normal LLC, but I think it’s okay because I don’t think it will drop below -18 ° C in the climate around here. 4L x 3 cans were prepared in advance. As a result, this wasn’t enough, so I ran to buy another can. I’m glad I got it in my neighborhood.

Bleed air of the coolant

Now, it’s finally time to bleed air of the coolant. NSX is famous for its model that does not easily bleed air. Basically, it is done according to the theory, but the trick is to lower the front side when removing the coolant, but this time raise the front side (because I think that the air will move to the higher side) .

After that, rub each hose, increase the engine speed, open the cock on the upper part of the radiator and several air bleeding valves in the engine room several times. Then, let it cool completely, replenish the reduced coolant in the expansion tank, and repeat the same process several times.

After passing through to a certain extent, we will also perform normal driving this time. After sufficient acceleration / deceleration / up / down / cornering, if you cool it again, the coolant will be reduced, so replenish it. For a few days, I would like to check the amount of liquid frequently and replenish it to complete.