NSX Health Check Service

[Kaz-kzukNA1]

2. Brake Master Cylinder
For the same reason above, in the past, it was mandatory to OH the brake master cyl (MC) regularly in Japan.
In UK and US, the workshop manual only tells to replace the entire brake MC as an assembly and there are no overhaul procedures.

Eventually, we’ll struggle to source the parts in the long term future so personally, I think it is best to know how to refurbish the existing parts rather than just simply replacing them.

Because of the price of the parts and the fact that it should be replaced as an assembly, it seems that many owners are running their NSX with aged brake MC or even with tiny leakage without being noticed.

It is recommended to OH the brake MC at least every 3 years or at the time of calliper OH.
While I was in Japan, it was very rare to see any sign of leakage or rust at the base of brake MC on NSX which was caused by the old leakge.

In UK, most of the NSX that I saw during the Health Check Service or during certain events showed sign of old leakage.

I would strongly recommend to have your brake callipers and MC overhauled on a regular basis regardless of your annual mileage.

Below the brake fluid reservoir, there is a brake master cylinder (MC). It is connected to the brake vacuum booster system which is black colour metal with round shape object at the front bulkhead.

Quite often on many NSX, I saw sign of leakage or trace of old leakage at the base of MC, i.e., the rust mark caused by the brake fluid at the black metal cover of booster system. You can see the trace of leakage around the stud bolt on the left part of the photo.


For some reason, it is not serviced regularly in UK. In fact, the English version of workshop manual states to replace the entire MC assy rather than to overhaul it. Probably something to do with the local regulation and to avoid complex issues caused by the human error.

The entire assys costs about GBP575.00 inc.VAT + labour so probably this is one of the reasons why it was not treated as regular maintenance item…

As long as there is no scratch/damage to the internal bore of MC, you can overhaul it and save a lot even including the labour charge.

As it is part of the brake system, I don’t think it is a good idea to wait until it starts to leak and then carry out the service.

The procedure is quite simple as it is similar to other cars. After disassembling the MC, clean it and inspect it carefully.
Then, use the overhaul kits to re-assemble.
Although I have never come across to the NSX that required the adjustment of the pushrod clearance at the brake booster, I always check it using the special tool as I don’t know the full service history of each NSX.

This is very important as you are either having too much play before the brake pressure rises or continuously applying small brake pressure which will be very dangerous.

Once everything is checked, the nice shiny overhauled MC is back in place.


Although it is not necessary, it may make your life easier if you bench bleed the MC prior to fitting it back on your NSX. If you consider the hydraulic line of entire brake system, you are going to take long hours to bleed the system without bench bleeding the MC first. This is the same even you use gravity bleed or other methods.

[NSXGB]

8. Door lock switch
Quite often, I was asked to investigate the electrical issues on NSX and one of the common failures is related to the non-waterproof connector being used inside the door. On this NSX, the driver side door lock sw was not working at all.
After long years, the moisture corroded the GND pin on the non-waterproof connector and lost part of the contact point. In order to prevent this from happening again, decided to use gold plated terminal with grease inside the connector. Now, it is fine…

Kaz, are these connectors a Honda part or standard electrical part? I need a pair for the third brake light so that it can be wired properly....I'm presuming they will be the same ad will clip into the plug housing?
If it's a Honda part, do you have the part number please?

[markc]

Hi Kaz, interesting to see the wear/rust on Paul's caliper pistons. I was going to undertake a rebuild of my calipers over the winter and suspect that I'll find similar damage to the pistons on my car.

A couple of questions if I may...
What does the caliper overhaul kit you mention contain? Do you have a part number to hand?
What other parts should I order?
How many pistons did you replace?
How much, roughly, are they each?

Thanks

Mark

[goldnsx]

What are the part no. for this?

[Sudesh]

You can buy the calliper seal kit from Honda. The seal kits are NO:1 in both pics.

But after that you can basically buy all the other bits too, pistons, bolts, retainers and so on.

Front callipers break down


Rear Callipers

[markc]

Thanks Sudesh. Mine's a 3.2 so I'll need the specific p/n's for the kits etc.

I'll do the fronts first so, might need a 12 & 15 (piston) for each side. Maybe new bolts as the calipers have been on and off a few times. The slider pins are good 'cos I checked and lubed them up at the last pad change (for the Silverstone track evening) just a month or so a go.

I must get myself one of these parts CD's

Actually there's probably no point in getting the part numbers as the muppets at UK Honda dealer parts desks seem to be incapable of suppling anything without a chassis number.

Cheers

Mark

[Sudesh]

Thanks Sudesh. Mine's a 3.2 so I'll need the specific p/n's for the kits etc.

I'll do the fronts first so, might need a 12 & 15 (piston) for each side. Maybe new bolts as the calipers have been on and off a few times. The slider pins are good 'cos I checked and lubed them up at the last pad change (for the Silverstone track evening) just a month or so a go.

I must get myself one of these parts CD's

Actually there's probably no point in getting the part numbers as the muppets at UK Honda dealer parts desks seem to be incapable of suppling anything without a chassis number.

Cheers

Mark

Hi Mark,

No problem at all. The parts pic I used will vary with the numbers, I used it just to indicate the calliper build. I have JDM parts system, UK and US. Some dealers can be picky with the chassis number issue, but with the correct part numbers I have never had a problem going to the dealer. Also alot of the part numbers on the parts CD systems have been superseded, so its always worth checking with the dealer. There will also be a difference in NA1 and NA2 builds.

Personally Mark, if doing a full rebuild I would replace everything, pistons, bolts, seal, retainers, and so forth.

[Kaz-kzukNA1]

Kaz, are these connectors a Honda part or standard electrical part? I need a pair for the third brake light so that it can be wired properly....I'm presuming they will be the same ad will clip into the plug housing?
If it's a Honda part, do you have the part number please?

Hi, NSXGB.

This terminal (pin) is from the OEM parts supplier 'Sumitomo Electric Industries Ltd'. They supply lots of looms, connectors, etc for many production manufactures including Honda.

The standard one is not Gold plated and I don't think you can get hold of it as it is not used for the production cars. It was used for the F1.
I don't know whether you can get hold of the standard ones in UK or not as I always get them from Japan. I still have lots of good contacts.

Not sure what the '3rd brake light' is, but if you are refering to the LED brake light on the rear wing, then you need different connector/pin type from the one in my photo.
You need the 090 WPC (Water Proof Connector) type one and the pin is also special to accomodate the sealing grommet at the end of the terminal. You'll also require special crimping tool to crimp the wire and the grommet to the terminal (pin) properly.

UK spec NSX is already pre-wired up to the left rear of the engine room for the LED brake light so if you want to buy the OEM cables for this, you'll need additional two cables.

If you want alternative solution, please send me an email as I may be able to make the cable for you but I need to check the stock of my parts first.


Regards,
Kaz

[Kaz-kzukNA1]

Hi Kaz, interesting to see the wear/rust on Paul's caliper pistons. I was going to undertake a rebuild of my calipers over the winter and suspect that I'll find similar damage to the pistons on my car.

A couple of questions if I may...
What does the caliper overhaul kit you mention contain? Do you have a part number to hand?
What other parts should I order?
How many pistons did you replace?
How much, roughly, are they each?

Thanks

Mark

Hi, Mark.

If you look at the 4th photo of the post #67, you'll see the part no and the parts included in the Front OH kit for later spec Front Calliper.
It's 01463-SL0-J01.
You need two of these for the Front.
For those who are interested, please note that the later models has different Front calliper piston size compared to the earlier ones and thus, requries differnt OH kit.

Some of the NA1 (3.0L) engine models were also equipped with this later spec callipers so please be carefiul if you are trying to distinguish the brake calliper spec by the engine size.

Also, if it is a used car, your previous owner may have upgraded the calliper to the later spec. It is quite common and for example, my NSX is 94 model but I'm running the 02 Type-R callipers.

You don't need to replace the pistons and other parts such as the bolt unless they are damaged. You can only judge it by opening the calliper.

For your referece, followings are some of the prices in UK.

HUK price for LATER spec Front calliper
Front OH kit: 80.89 inc.VAT x 2 = 161.78
Front Piston 34mm: 38.16 inc.VAT x 2 = 76.32
Front Piston 40mm: 63.94 inc.VAT x 2 = 127.88

Addition to these, I normally replace the following for the front calliper service. Parts no and image included in the same photo of post #67.
Bleeder screw: 4.67 inc.VAT x 2 = 9.34
Cap, bleeder screw: 2.70 inc. VAT x 2 = 5.40

So, if you go down the route of HUK, you'll be looking at at least 380.00 just for some of the Front Calliper Parts...

As I always service my calliper every 2 -3 years, I don't want to pay this figure so I always order them from Japan or US.

Hope this will help.


Regards,
Kaz

[Kaz-kzukNA1]

Recently, I was working on another NSX for Brake Calliper OH, Master Cyl OH, Driveshaft service and so on.

The owner bought the NSX as a used car and there were several previous owners in the past.
Initially, the owner brought the car for my Health check and there were many items to be serviced so we discussed the plan based on the available time and the budget.

1. Brake Calliper
The owner had the new brake pads installed at a certain garage and also he was under the impression that the callipers were serviced in the past by the previous owners.
However, at the time of my NSX Health Check Service, I drove this car and the brake performance was nowhere near to the original spec. It was also causing lots of judder when the brake temperature was high. The Brake Master Cyl looked terrible but I’ll touch on this later.

It was agreed to carry out the brake calliper and master cyl OH, replace the brake disks, replace the brake hoses and paint the callipers in matt black.

As soon as I started the service, I found the 1st issue.

One of the boot was damaged when someone carried out the calliper OH or when re-installing the callipers after the new pads were installed. It was not just one side but on both R & L Front Callipers so it was a human error. Also, found that the orientation of the slider pins was wrong, the torque for the rear calliper bracket was too low which was really dangerous and so many other issues.

I’m glad we carried out this OH service as the owner was planning to take this NSX on Nurburgring in near future.

All of the pistons looked very healthy as they were replaced recently but not sure whether it was serviced by someone who knows the specific knowhow for the NSX or not after finding so many issues.

It’s a standard calliper similar to other production cars but requires some knowhow.

The Front and Rear Calliper OH parts. The new Front Disk by Dixcel. Thanks to Andy at Vtecdirect. We placed the order long time ago while he was offering special deal on all products as well as the NSXCB member's deal.