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

While removing the coolant hoses and blower motor fan for other services, decided to finish the Clutch Hydraulic service.

It is one of the most common failures on our NSX.


Sooner or later, you will see the fluid leakage from the Master/Slave cyl or from the hose where the fitting is crimped.


Almost all of the failure with the CL Hyd system will start as a tiny leakage so it is important to deal with it at the first sign of the issue.


On this NSX, the Slave cyl was leaking and the fluid level was at MIN.


If it goes below this, eventually, it will suck the air into the system and will loose the ability to disengage the CL.

My latest CL Hyd service package.


It makes sense and highly recommended to replace Master/Slave cyl and the CL hose as a set.


Recently, I ordered these parts for several owners and also provided the parts list to others so that they can get part of the package from US.


Please note that you must select the correct Master Cyl spec depending on the RHD/LHD NSX.


Cotter pin is also different but not a big issue as you can easily find the replacement.


Acura US won’t have the RHD CL master cyl in their parts system.

The CL hyd pipe was dangerously too close to the brake vacuum booster line.


In fact, it was scratching against it.


Will be properly positioned after installing the new master cyl.

By now, at the bottom of your reservoir under the round small float disc, you will find the build up of dark residue that is the deteriorated piston seal.


This one was full of debris so cleaned it as much as possible to this level.

Quickly, bench bleed the master cyl on the car.


Unlike the brake master cyl, you don’t need to get rid of the tiny air bubbles inside the cyl at this stage.


The purpose of this proceduer for the CL master is to just prime the cyl so that it will encourage the fluid to run down the internal wall during the final bleeding process.


Without priming the master cyl, you may struggle to get any resistance at the pedal during the bleeding process as you have too much air in the CL pipe line.



I heard lots of people struggling to install the CL master cyl.


It is caused by the small alignment difference between the holes at the bulkhead and the ones on the CL pedal bracket.


Extra hands will definitely help but if you are doing it on your alone, then loosening (not removing) the upper CL pedal bracket bolt and wiggling the CL master cyl from the cabin side will work on many cases.

New master cyl in place.


Moving onto the Slave cyl and CL hose area.

Kaz