New guy with a brake question on 1986 KDx200

[SnakeDriver]

Hello All,
I must say I like your forum. I just got my first KDX, on the recommendation of Rick "Super Hunky" Sieman. It's an older model, just like me! It's an air cooled, KIPS equipped '86 KDX200. It needs a little work, but it hasn't been beat to crap like some of the other projects I have taken on. So here's my issue: The front brake was very mushy, and the seals were leaking on the caliper. I took it all apart, and it doesn't look too good. I am thinking about retrofitting a different master cylinder and/or caliper. Here are my choices so far:

Honda CR master cylinder, rebuild the OEM KDX caliper
Buy a complete system from an 89-94 KDX200 (Will this fit?)
Complete system from a 95-up KDX (Will this fit?)
Other. (I'm open to suggestions)

Does anyone have experience doing this?

Thanks!
Bert

 

[dirt bike dave]

Not sure if newer KDX systems will easily swap.

I'll bet you have a very large bubble in your line that is not coming out with normal bleeding. I had that problem on a '90 I bought used. Very spongy and weak brakes. Bubble would not bleed out until I took the braking system off the bike and hung it straight on a wall, tapping the hose with a screwadriver handle.

That and a fluid change made a huge difference.

Personally, if it were my bike, I'd rebuild the caliper, get the bubbles out and put in good fluid. Spend the money you save on a brake system upgrade on other things, like catridge fork emulators, new tires and whatever bearings and bushings are worn out.

Oh, and if the bike is stone stock, you will want to lean out the jetting and put in stiffer fork springs, just like every other KDX 200 ever made, lol.

 

[glad2ride]

Good job on getting the bike!

Rebuild the stock one, as the other ones that fit won't be much better. 1993+ won't fit, anyway.

 

[SnakeDriver]

Thanks for the advice guys. When doing the hanging and tapping trick, you hang it right side up, correct? I've also read the threads about zip-tying the lever into the squeezed position and leaving it like that. Has anyone had success with this method?

Thanks!

 

[dirt bike dave]

For mine, I hung it caliper up for a few days, then took it off the wall, elevated the caliper on some blocks of wood, then bled it off the bike with the caliper at the highest point. Big bubble came out. This was after I had tried bleeding the bubble out on the bike about 10 times.

I've also heard you can hang it with the reservoir/master cylinder up, and the bubble may spontaneously bleed itself out of the master cylinder, but I never tried that.

 

[glad2ride]

You may want to look into one of the vacuum systems. Everyone seems to love those.