NSX Health Check Service

[Kaz-kzukNA1]

8. ABS and brake bleeding

Once again, it’s time for the ABS service.

Looks like the previous owner(s) were activating the ABS regularly as none of the four solenoids were sticky. They were all operating fine which was a good news.


Still, the system was full of air and initially, the pump motor didn’t sound well so flushed it several times. It started to sound normal after 3rd flush.


Each solenoid was flushed using the proper 090 size pins and the fluid was replaced before moving to the next solenoid. Quite often, people just replace the fluid inside the ABS reservoir without flushing all four solenoids.
Without this process, there is no gurantee that all of your solenoids are healthy. Also, you will be mixing the new fluid with the old one which is stored behind the solenoid valve.

[Kaz-kzukNA1]

This NSX has Brembo system on the Front so requires extra time due to the two bleeder screws per corner. I use pressure bleeding process so no big drama for me.

It was recommended to the owner to have the Brembo calliper serviced as they require frequent maintenance than the normal ones. They don’t have dust boot at the entry of the piston so regular maintenance is a must item.

Also, the bleeder screws were heavily corroded and over-torqued in the past so it was best to replace them.
As the owner was planning some upgrade to the rear calliper in the near future, it was agreed to just bleed the system on this occasion.


The original fluid inside the reservoir was very dirty so glad to replace it now.

Regardless of the mileage, it is recommended to replace the fluid at least once a year as brake reservoir is not a sealed container.

[Kaz-kzukNA1]

9. Coolant Hoses, header tank, thermostat, etc.
At the end of the track session, it is important to carry out cool down lap, ideally for a complete lap distance. Same treatment was applied for the safety and medical cars that I used to track every two weeks or so for one of the race category.


Looks like this NSX was being used a lot on the track but possibly, without enough cool down lap as some of the coolant hoses were really cooked.


So, it was recommended to replace all of the hoses including the header tank, cap, hose clamps and so on.

This NSX is NA1 DBW MT model so there is no EACV and thus, we need to select the right combination of the hoses and clamps for each models.

For our NSX, you will need to order different combination of coolant system parts depending on the NA1/NA2, DBW/Non-DBW, AT/MT, RHD/LHD and so on.


Recently, Honda changed the bottle design of its Type-2 coolant.
It now holds a little bit more extra coolant as well.
Although it says 5L on the bottle, it used to contain about 5.4L but now it comes with 5.5L of coolant.
For NA1 MT, you will need full 16.5L.

[Kaz-kzukNA1]

Although the thermostat was not stuck open, the rubber sealing was already deteriorated and partially missing.


The rubber gasket was already starting to leak and thus resulted in lots of corrosion around the thermostat housing and cover.


Before installing the new thermostat, the area was cleaned and polished to make good sealing.

The header tank was also very tired and started to crack at several places and about to leak. The cap was also replaced with new one.


After time consuming process, new hoses and several other parts were installed and it’s now time for the vacuum test and coolant feed. Kept the system under vacuum for 5min to confirm that there is no leak and then the coolant was fed through the vacuum tool.

After that, the engine was started to pressurise the system for one final check and then left the car overnight to check the coolant level.

[Kaz-kzukNA1]

10. Air Con Climate Control Unit (CCU) and Cabin temperature sensor
Considering the age of the car, there were some question marks on the A/C CCU so it was decided to refurbish it together with the cabin temperature sensor as it was making annoying noise.


As expected, lots of capacitors were already leaking and causing lots of damage to the board. Had to repair several pads and tracks after cleaning all the leaked acid.


Cabin Temperature sensor was full of dirt and once it was overhauled, there was no more noise.

There seemed to be an issue with the power transistor at the blower fan motor so that will be the next service item for the future.

[Kaz-kzukNA1]

11. HID repair
Just when I thought I was ready to return this NSX to the owner, I found that the left side headlight dip beam was dead.

Previous owner(s) installed the aftermarket HID conversion system and the burner was simply dead. However, the installation was not beautiful and even the current owner experienced intermittent issues in the past.

Normally, I’m happy to repair the existing looms and re-install the system but for this one, I recommended the owner to take out all of the looms/connectors and replace them with the new system.


The installation was so bad that many looms were already squashed and the terminals were very rusty due to poor water proof. Some of the original terminals were modified in a wrong way resulted in poor connection.

Because of this, although I had new spare HID burner, I didn’t want to use it on a un-reliable system.


I decided to give up my old used burner to the owner and modified the burner loom to accomodate the specific connector from the dead burner.


After long delay, finally I managed to wash this NSX and returned it to the owner with Photo CD to show what was done over the last 4 weeks.

Currently, I’m working on NA2 face lifted MT NSX for several services including the timing belt, water pump and so on.

I'm aiming to return this NSX in time for Japfest and then I can start thinking about the installation of the new headers on my NSX…

No time for the ABS upgrade before Japfest though....

Another happy owner.

Regards,
Kaz

[Kaz-kzukNA1]

Hi, all.

Over the past few days, I was carrying out my Health Check service for some of the owners as well as supporting lots of other owners through PM and email.

During this short period, I found 2 NSXs with Crank Pulley about to fail when they visited my place and also there was another one that I found through the email support.

One of them was very low mileage (below 50k miles) 95 model and it has been serviced regularly at main dealer so once again, regardless of the mileage, please make sure to replace the crank pulley at the time of timing belt service.

It is not included in the standard Honda service in UK.

In Japan, this parts is a ‘MUST’ item to be replaced during the timing belt service among the NSX specialists.

In US, some of the owners are using the metal shield behind the pulley to protect the timing belt and the plastic cover from being damaged but it won’t stop the pulley from failing so as far as I know, very few owners are using it in Japan.


To check the crank puley, it is best to lift the car up and wiggle the weight balancer to feel for any movement.
You should not feel any movement at all at the balancer when it is tightly bonded to the pulley.

You can do a quick check as well but please note that it is best to feel it than visual inspection.

Please click on the photo to get enlarged image.


When you look at the crank pulley from this axis, the outer pulley and the balancer will be parallel.


When the balancer started to dislocate itself from the pulley, you can feel the wiggle if you can touch it but also you will notice some angle/not parallel at the balancer against the pulley.


As in my post #245 within this thread, MT and AT uses different crank pulley model so please order the correct one for your NSX.

13811-PR7-A02: For MT GBP348.02+VAT from HUK
13811-PR7-A11: For AT GBP347.93+VAT from HUK

It’s not a cheap parts but it's an insurance for many years ahead and you should be able to save a lot by ordering it through our NSXCB vendor vtecdirect or from US or Japan.

The cost for worst case of crank pulley failure would be in the order of 1,000s any way...


Regards,
Kaz

[greenberet]

In Japan, this parts is a ‘MUST’ item to be replaced during the timing belt service among the NSX specialists.

Wise words. If I had known that a year ago, it would have saved me a lot of trouble.

[Kaz-kzukNA1]

Hi, all.

In March, I was in Japan for a while for business meetings and I brought back many parts with me for some of the owners as well as for my NSX.

This week, I decided to install the ABS upgrade kit and the aftermarket headers from KSP Engineering Japan.


1. ABS upgrade
It was a good timing as my brake fluid was about one year old and time to be replaced along with the ABS flushing.

During my visit to Japan, I was lucky enough to compare several different spec NSXs.

After comparing the old and new ABS on the same day at skid pad and down slope covered in snow, I can comfortably say that the latest ABS should be on all of the NSX.

This latest ABS module is nothing special compared to the ones on most of the modern production cars with ABS. You can find the same/similar ABS module on lots of them and it’s just the software setup being different.

This means that the old ABS is simply not up to the modern technology and in my personal opinion, there is a big design issue with the original ABS.

After the ABS was activated a few times, it will loose the stand-by pressure inside the accumulator and the ABS pump will kick in to restore the lost pressure.

If the ABS pump was triggered while the driver was applying the brake and locked the wheels, there is not enough pressure to kick back the brake pedal and thus, the tyres would be continuously locked unless the driver was able to manually lift the brake pedal for a while.

As you can imagine, most of the time, the ABS would be triggered under panic situation and it would be very difficult for most of the drivers to release the brake pedal under this condition.

If you have the opportunity to test the old and new ABS on a long-long down slope covered in snow or at the skid pad, you will find out the huge difference immediately.

During the test session with the old ABS, even it was well serviced and in perfect working order, the ABS pump kept operating for ages with the brake pedal to the floor with no kick back and the car was sliding down the slope with no steer as the tyres were all locked. You would need to release the brake pedal to act as a human ABS.

With the latest ABS, nothing like above happened and it was just so comfortable applying the brake under the same condition while turning the car through the down slope corner.


For me, the latest ABS is like the investment for the future. With the latest ABS, I may be able to stop my NSX before hitting something whereas with the old one, I will pray for the luck but probably end up with hitting the object.

So, started to work on my NSX…

The bulky and heavy original ABS system VS the new one.

Quite surprised with the weight of the old system when I tried to remove it out of the front compartment. The new ABS is very simple and light. The wiring is also very simple as the controller is now integrated into one package with the ABS modulator.


The most time consuming part is the removal and installation of the brake pipes. It's like dealing with lots of spaghetti.


With the new ABS, there is a Proportioning Valve for the Rear brake pressure.

[greenberet]

This week, I decided to install the ABS upgrade kit and the aftermarket headers from KSP Engineering Japan.

If the headers aren't mounted yet, could you measure the length of the primary tubes for both the front and rear cylinder banks?