2002 KX 250 front brakes

[myGreen]

I was looking to upgrade the front master cylinder on my KX. I have read that the 05 and newer ones are a great, easy swap. What is the best and economical route to go? Thanks!

[KevinTwoStk]

Based on part numbers, I don't think you'll gain anything. The part number I found was 43015-0167, and it was the same for 2002 all the way through to 2007.

Side note: there's an old part number for 2002 (43015-1674) but it refers to the same exact physical part.

I upgraded my 2000 KX 125 master cylinder to a 2003 KX 250 master cylinder and it made a HUGE difference, but the 2000 master cylinder is a different part number (and a poor performer).

Assuming your master cylinder, brake line, and caliper are in good working order, I'd say you could see a big benefit by using an oversized rotor with a caliper relocation bracket. EBC, Galfer, and Braking are all good sources to check.

[KXDINO]

The 270mm oversize rotor kits work well,we also use kxf 13 front oem pads as well,MXA say the ride engineering billetfront caliper works well, with 2mm bigger piston ,these 3 items will make your front brake awesome.We even put the 13 front master on a kx250 06 for the better feel it offers,this is the order i would take.

[supergenius]

I went to a CRF 450 Front master. What a difference. No more spongy half assed s**t. Works great.

[sandblaster]

I went to a CRF 450 Front master. What a difference. No more spongy half assed s**t. Works great.

And, when used with braided SS lines gives you very positive brake feel.

[myGreen]

Well I purchased a brake setup from a 2006 kx250F (supposedly) and a stainless steel brake line. I put it all together and the brakes are still mushy and crap. I bled and bled them. They are no better than my old brakes. I swapped it out the mastercylinder, line, and calipers. What gives??? Is it still the same brake setup for a 2002 as a 2006?

I have attached images, the master cylinder looks the same, just some different stampings. Are these two in fact the same part? Thanks!

Old MC


"New MC"

[sandblaster]

Hello.
I don't believe there is a significant difference between the 02 and the 06.
However, here is some things that I have found that can make a big difference.
When brakes are feeling mushy I completely disassemble my master cylinder and caliper.
I remove the seals... everything.
Then I carefully clean every single part and inspect to make sure there is to detritus...
Reassemble, fill, and test.
If they are still mushy and you know your SS line is good then I get a caliper and master cylinder rebuild kit.
I remove the brake rotors and soda blast the part that the brake pads rub against.
I mask the rest of the rotor off to keep it's appearance.
Then I install brand new pads.
I've been using the EBC MX-S pads with good success.
If this won't toss you on your face... Then you may have a crack in one of your castings...

[myGreen]

Thanks for the feedback. I just can't believe my bad luck with two completely different brake systems. I think I will go ahead and try the master cylinder rebuild kit first. That should at least tell me if the cylinder is in fact good or bad based on getting pressure to build properly.

[don46]

Brakes are the whole package, your master cylinder may be fine, the problem may be the caliper. worn pads and worn pin areas cause movement, and so each time you engage the brakes much of the travel is taking the movement out of the calipers, new pads help some. I have used the 250f brakes with great success. There was a company that specialized in KX brakes, they would drill the pin area and install brass/bronze bushings to remove all play, install a 1 piece oversized rotor, and stainless line, they worked great. I've also found that the brakes are better with a 1 piece rotor. and as someone said you can get a oversized rotor, they work.

[yeomans]

On, my 2002 I'm running the Galfer oversize rotor, Galfer braided lines and some DP pads. Scary power especially in the front just with the stock master cylinder.
Anything on your pads preventing a good grip?
Banjo bolts tight? Not pulling air?
Rust on piston?
Bad/ dirty seals?
I've ran the stock set-up and my new set-up on both the 1999-2002 kx 125's and 250's and I can say the stock braking package was a little mushy for my liking.
I'm going to try using the Braking front caliper and braided lines with stock master cylinder on my 2002 250/500 conversion.