KX Riders

Maintenance & Technical => KX250 / KX125 => Topic started by: John on September 18, 2003, 08:42:07 AM

Title: Muchy front break
Post by: John on September 18, 2003, 08:42:07 AM

I give up!!!!!!!!!!

How the hell do I bleed the front break circuit properly?

I have air in the system and I can't seem to be able to bleed it out! Is there a special trick or just plain magic? I have bled a lots of break systems (I used to work as a mechanic) so I should be able to do this!

The front breaks have never been good on the 125 I have. After hitting a tree last weekend I finally decided to do something about it:

I have had the front break lever tied to the handle with a strap for 3 days! (system under constant pressure)
I have dismounted the caliper and nailed it to the ceiling (no pressure + caliper = highest point - two more days).
Spent half a liter of oil in total.
Still soggy!

The result so far is two itsy bitsy bubbles and a tiny improvement in the breaks. I can do stoppies - but I can also squeeze the lever tight to the handle bar.

It is not that I am stupid or anything (no smart ass comments please) BUT I am lost here.

Could it be the brake line that need replacement or is there a trick to bleed the system?

Help!

Title: Muchy front break
Post by: Paul on September 18, 2003, 10:13:48 AM

I had a CR500 that had a small weakspot in the line where the pressure would "bulge" the line inside the liner. Just a thought...

Title: Muchy front break
Post by: teamgreen500 on September 18, 2003, 04:37:34 PM

Try the system with your brake line (from K5 or another bike...) for a test. That will answer the Q posed by Paul.

If still bad, try "pulling" vac. with a pump.

Title: Muchy front break
Post by: John on September 18, 2003, 08:57:19 PM

So really, there is no magic probably just a broken brake line... I'll replace it and see what happens.

Title: Muchy front break
Post by: John on November 09, 2003, 06:08:29 AM

Nope, the brake line was OK and the problem was caused by some grit in the tiny, tiny hole in the brake cylinder oil reservoir. The hole is located under the rubber seal. I tried to take a picture but it didn't come out too well and the stuff is now back on the bike.

Title: Muchy front break
Post by: doordie on November 17, 2003, 08:49:16 AM

Paul!
The H...a is a weak spot allways!!!!

John!
Thx for info,can now tell a friend about it,he have the same problem.

Title: Muchy front break
Post by: gowen on May 02, 2004, 07:35:36 PM

Hmm, my K5 is having a serious the same problems, I will try that, should I just blow it with air?

Title: Muchy front break
Post by: John on May 02, 2004, 08:02:46 PM

I used a single pin from a steal brush. Small diameter and does not bend. Whatever it was, it was hard and didn't go away by just blowing air.

//John