Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

Managed to find some time to work on the NSX today.


As mentioned a while ago, instead of cleaning and overhauling the heavily leaked/corroded master cyl, decided to replace it with new one including the reservoir, filter, cap and the fluid level sensor.

Time to check the pushrod clearance while keeping the vacuum at specific rate.


It is very unusual to adjust it but as I don’t know the service history of each NSX, this is a MUST procedure.


Otherwise, the owner may end up with extra play before the piston starts to move or even worse, the piston is always pushed a little even without touching the brake pedal.

Unlike the Clutch Master Cyl, it is best to bench bleed the Brake Master cyl.


Otherwise, you are going to spend long hours and waste lots of fluid to push out the super tiny air bubbles trapped inside the cyl.


As it states, brake fluid is a fluid but the viscosity is fairly high compared to the water.


If you don’t bench bleed the Brake master cyl and kept big air pocket inside there, with the effect of the viscosity, the surface tension and tiny diameter of the feed ports, you are going to break the air pocket into hundreds of air bubbles every time when you move the two pistons during the normal bleeding process.


Pushing out these tiny air bubbles out of the cyl without tilting it at the specific angle is time consuming and it is impossible to aim at this angle without taking the master cyl out of the car.


Also, if you don’t prime the cyl, quite often, you won’t be able to see any fluid coming out of the bleeder at the calliper end as all you are doing is pushing back and forth the big air pocket inside the master cyl or the brake pipe.


Therefore, bench bleeding of brake master cyl is not a MUST procedure but saves your time and cost at the end unless you are using specific equipment designed for bleeding purpose.

In the process of pressure bleeding.


During the 1st round, the purpose is to push out the air as quickly as possible so you can open the bleeder quite wide.


Once 1st round is done, remove the pressure bleeder temporarily and press on the brake pedal hard many times to activate the parking brake auto adjuster and also to check for any leakage.


Reconnect the pressure bleeder and keep the system under pressure for several hours before going through the callipers again for the 2nd round.


2nd round is more of a double checking purpose so you should not see any bubbles at all.



Happy with the result and pedal feeling so Brake OH is pretty much done.



Just need to keep the car on the lift overnight for final leak check and move onto the ABS and driveshaft service before I can finally carry out the test driving session to determine the places where it is creating multiple interior noise issues.


Hope I can take this NSX to the alignment place next week.

I also need to carry out MOT on my two cars....


It's going to be busy again next week...

Kaz