front master cylinder swap with 450r or 400ex

[dtowndiesel]

Hi, will it work to replace my 250r front brake master cylinder with one from a 450r or 400ex? I have heard of other 250r's with a 450r master but I don't want the plug in on the bottom for the brake light. I also want to make sure that my RTC brake handles will be universal to either the 400ex or 450r unit. If you have any info please share it. Thanks

[deathman53]

I'm using 400ex masters, mine don't have the plugs on the bottom. The Rtc handles fit them also. I' using a 450r asv front brake lever on one of them, also. It might be the 05+ 400ex and all 450r that have the plug at the bottom. I'm using 99-04 masters, they don't for sure.

[danhung11]

I have a 400EX front master cylinder on my R. Just make sure it is one that does not have the actuator for the brake like. They are like $50 from Service Honda... I think.

Any year from 99-04 400EX should work.

I have a very nice one if you are interested. PM me.

Dan

[312R1]

I'm using a 450R one..works great.

[heelclickinonaR]

I'm using a earlier model 400ex master cylinder with a 450r lever. The 450r lever is shorter than the yard stick they call a lever on the 400ex and it's also adjustable.

[dtowndiesel]

Thanks guys for all your help. I just bought a 400ex master from danhung11. Have a great night.

[danhung11]

Originally posted by dtowndiesel
Thanks guys for all your help. I just bought a 400ex master from danhung11. Have a great night.

You should have it by Wednesday or Thursday. ;)

[chamberlain31c]

99-04 400ex master will work and 450r lever will work with the 400 master cylinder correct? what year lever? or are they all the same?

[danhung11]

Originally posted by chamberlain31c
99-04 400ex master will work and 450r lever will work with the 400 master cylinder correct? what year lever? or are they all the same?

Correct. I have a perfect lever if you need it. PM me if interested.

Dan

[peeping TOM]

ive got a 450r on mine.loads neater then the 20 year old master cylinders.

[thedeatons]

To make this thread a bit more informative, the important aspect of the master cylinder is the piston size. The 250R has a 1/2" piston, which when converted to metric equals a 12.7mm piston.

The following is a direct swap:

-New TRX450R/TRX400EX/TRX250EX (All have brake pressure sensor). These have a nice rubber boot, a clean new look, and a reach adjuster.

-New CRF250F/230F (No brake pressure sensor). These have the same nice look, rubber boot, reach adjustment, and a smaller/sleaker reservoir. They should also work fine.

If you switch to a smaller piston such as an 11mm, you will have more brake feel, but the lever will need to travel further toward the grip to achieve the same stopping power.

If you switch to a larger piston such as a 5/8" or 19mm, the lever will barely need to move before locking the brakes, which will take away your lever feel, and give the brakes a wooden feel.

[Jonny B]

I am running a CBR 900 streetbike front master cylinder on my lobo and can say it has GREAT stopping power...it is no effort to lock up the front wheels even though I am running single piston 400ex calipers and spindles. Try that if you want to be impressed with your brakes!
Jon

[trx250rider]

i also use the cbr master cylinder.looks nicer to.

[thedeatons]

That is a good example of what I said, less lever travel but a loss of feel....

What size is the piston? Should be a number on the outside of the front of the casting.

[Jonny B]

On the front of my cbr master it says 5/8 near where the line connects...as far as the feel, there is no mush like on a 250r master so you need to be aware that less effort on the lever does a lot of stopping. I mainly use the front brakes when I NEED to stop instantly anyways so it works great for me. There is a lot of rear braking going on on the trails I ride. Not too sure what you mean by a wood feeling?...maybe you are saying the braking is like a switch...on or off. I like using less effort to stop quicker.