[thedeatons]

I bought a TRX450R master cylinder instead. It has adjustable reach and looks brand new...

Thanks though!

 

[thedeatons]

The CRF150/CRF230 master cylinder was a bad idea, because it only gives 1/2" clearance from the bars, not enough for a thumb throttle.

If someone is running a twist throttle and wants this I will sell it for the $25 I paid plus shipping...

Now looking for a TRX450R master cylinder. All the same features but a bit more clearance....

 

[thedeatons]

Got my 1/2" CRF150 master cylinder in last night. Will let you know how it goes and post pics. $25 on Ebay and it only needs a new lever!

 

[thedeatons]

If the fluid does get low I don't plan to add, that is a bad idea on a closed loop system. If you add more then install new pads the pads will rub on the rotors.

Same thing happens with cars...

I get what ya mean though!!

 

[thedeatons]

Yes, it is a swap.

Turns out the new TRX400EX and TRX250EX both have the same front brake master cylinders as the TRX450R, all of which will work.

The CRF150/230 have to be "F" models, the other models will not work as they are 11mm.

Even with pads wearing down I have never seen fluid fall to even the middle of the sightglass, so I am going with the smaller reservoir to try out....

 

[thedeatons]

Nope..... Here is the thing. The master cylinder's piston is what matters, not the physical size of the reservoir or the lever, or anything else.

The 250R comes with a 1/2" piston (12.7mm) to work the OEM Honda dual piston calipers at each front wheel. Therefore an exact replacement would be any master cylinder with the same piston size, such as the TRX450R or CRF150/230 master cylinders, both of which are 1/2" pistons (12.7mm).

The 400EX has different brake calipers, and therefore requires a different master cylinder to appropriately push them outward to the brake rotors.

Just because you can fit it on the handlebars doesn't mean it will work right. There is a science to this.

The CR series bikes have 11mm pistons for instance. This smaller piston would offer super feel for the brakes, but would require a lot longer lever travel to lock the brakes up, due to the fact that the smaller piston pushes lesss fluid. Some sportbikes use a 19mm master cylinder piston. This would allow you to barely actuate the lever before the calipers lock onto the rotors, but would take away the lever feel needed to slow down properly, making the brakes have a "wooden" feel).

Because I am keeping the piston sizes the same everything will work exactly the same, just look a whole lot newer/better.

 

[thedeatons]

Nope, not yet, but these two above will substitute just fine. When I see a 400 I will check it out. The important thing is that 1/2 is stamped into the casting (meaning a 1/2" piston size) and that you like the look.

The CRF230/150 is so slim it looks awesome....