Weak front brake 04 ec300

[jt633]

Hey guys have a front brake question, ive put new pads on bled them every way possible but the feel at the lever is weak they work about 75% better once warm but i like my front brake super strong do i need to rebuild the master cyl or the caliper? Pretty sure my last gasser had a honda crf front brakr setup thanks in advance

 

[Zman]

Sounds like you have air in the system. Did you try to bleed the brakes? One quick method is to push the caliper pistons back in the caliper and it will force some (maybe all) air back through the master cylinder and into the fluid reservoir. Sometimes it works sometimes it does not.

 

[jt633]

Yes like i said i tried everything would like to save some money if i dont have to buy both kits

 

[cbutler]

Get a zip tie and pull the lever as far back as possible. put the zip tie on around the bar and lever let sit over night.

 

[jt633]

With bleeder cracked? Also what other bikes have same master and caliper? I know japs are the same but need a year or years lol

 

[hamilton]

The zip tie trick works, but the trapped air rises to the highest point of the brake system. ie usually the loop in the hose. raise the resevoir or lower the caliper.

 

[cbutler]

With bleeder cracked? Also what other bikes have same master and caliper? I know japs are the same but need a year or years lol

No do not crack open the system. You mite do like hamilton said or just undo the line so you can pull the line to the side so the master is the highest point but I have never had to do this but it could not hurt.


Any year XR400 front and back

 

[jt633]

How is the air released? If theres no escape for it

 

[cbutler]

It just goes into the master cylinder try it it mite help mite not but it is free

 

[jt633]

I got it zip tied right now thanks for the tip!

 

[pscook]

I find it hard to believe that simply pressurizing a hydraulic column allows air to rise to the top. If so, wouldn't it be simpler to go for a ride, and use the brakes? If this trick actually worked, your brakes would be self bleeding every time you went for a ride (squeeze, release, repeat). I don't buy it. It would also self-bleed sitting on the side stand, as the master is highest when the bike is leaned left with bars turned left. All bubbles rise to the top, so just let it rest for a couple of days. Good as new with zero effort!

When the master cylinder piston is depressed, it blocks the return hole and no fluid or air loops back into the system. If the bleed hole was exposed, the system would never pressurize. If there is any air in the system, it is most likely trapped at a high point in the caliper, or in the banjo bolt at the master.

Bleed the line at the banjo bolt at the master, then bleed the banjo bolt at the caliper, and then bleed using the bleed screw on the caliper.

I'm just a cynic with a mild case of experience with closed and open loop hydraulic systems. An open loop system will self bleed. A closed loop will not, regardless of how much pressure you exert on a column of fluid.

 

[jt633]

Pscook i have tried bleeding that way! The brakes work well when warm
But they arent tight lever comes in almost all the way gonna the zip tie thing if no luck im gonna rebuild caliper and master