NSX Health Check Service

[Kaz-kzukNA1]

1. Brake Calliper
Until several years ago, in Japan, we had to carry out the calliper overhaul (OH) every 2 – 3 years by law.
Since the rubber material has improved a lot, we are no longer forced to replace the boots, seals, cups and etc under the new law. However, it is still recommended by many reputable garages in Japan to have the calliper OH every 2 years in order to inspect the inside of the callipers and to prevent the rust from getting inside.

It seems that for UK NSX, the calliper OH is not carried out on a regular basis. In fact, I noticed that this is not just the case for our NSX but also for many other cars on the road.

I was lucky enough to drive many NSX based in UK and none of them were showing the same level of stopping power or the solid pedal feeling of the original spec.

One of the reason for this seems to be that the owner believes or being told that the OH is not required if the car was not driven regularly or if it is at low mileage.

Especially, among the owners with super low mileage NSX, the calliper has never been touched for nearly/over 10years.

This is very worrying as the piston(s) inside the calliper just sits at the same position for many months/years if the brake pedal or side brake were left without any movements. Unless your NSX is kept inside the 24Hr air-conditioned garage, the moisture in the air will eventually get into the calliper causing the rust slowly. It will damage your piston, cause seizing and in the worst case scenario, it will cause brake fluid leakage or entire calliper to be replaced.

Therefore, regardless of your annual mileage, it is essential to have your callipers serviced at regular interval. Needless to say, the brake fluid should be replaced every year for standard NSX regardless of the annual mileage and for those who take out their NSX on track, well, I don’t need to say anything as they are more experienced than me. For those who are interested, they are replacing after every track event or after a few events depending on the brake fluid used.

Recently, I was working on one of the member’s NSX. Prior to this, the owner took my NSX Health check service and I drove this particular car. Straight away, I didn’t like the feeling of the brake.

It is a low mileage, well looked after and being serviced regularly at the reputable garage so I thought it just needs good bleeding and going to be an easy job. Wrong….

The Front calliper before the service. As you can see, it is very clean and even I was not expecting to see the problem inside…

Most of the pistons showed rust under the lip of dust boot but one of them was particularly bad and didn’t move smoothly. It had rust even at the seal area and thus, enough damage was done and had to be replaced.


This is quite common for NSX not driven regularly and if the calliper was not overhauled on a regular basis.
There are lots of know-how that are not on the workshop manual to minimise these rust getting inside the calliper and these can only be done at the time of overhaul. Therefore, regular service on the calliper is a ‘must’ item.

So, the Front calliper was inspected in detail and serviced using the overhaul kit with additional parts based on the past experience. The bleeder plug and cap were also replaced with the new ones.