Problem with braking coming off Boost??

[Tookes]

I'm having a problem every time I get between 8 to 15 lbs on my boost, I have to pump my brake twice to get them to work. I the brakes work just fine on the trail or lower speeds, I've bleed them twice and I'm about 95% I did it correctly. Suggestions please, thanks

 

[HYFLYR]

Are your pads wearing down?

Do you have enough fluid in your resivoir?

 

[DamonJones]

Any chance the brake line is getting hot from the turbo? Just a thought.

Also maybe check to see if they are dragging. Maybe they are fading for getting too hot. Again just guessing and throwing out ideas.

 

[motorman]

95% sure is still 5%doubt lol
fill brake resevoir,squeze and hold brake lever,loosen bleed screw,air and fluid should come out,repeat until only fluid comes out. 100% sure

and check to see if the turbo is heating up the oil in the brake line

good luck D

 

[Tookes]

I've bleed them and fill them and bleed them again. I think it from the heat as well, but I've also put some heat tape on the brake hoses... It's the "when" the don't work, unless I pump them twice that's got me at a lost.

 

[DamonJones]

Heat tape probably not enough. The fact that you've put it on tells me heat is an issue. Buy a longer line and reroute it away from the heat source. Best I can figure without seeing it.

 

[REXX]

Here's a thought. Are you sure it's just not your turbo still powering you? Also,with turbo you've got a lot more track spin to contend with therefore a lot more forward mometum track mass to slow down. Yamaha designed the brakes for 150 hp. not 250 - 350hp.

I run 16 lbs. boost. I've done jumps where I let off the throttle in mid air, but still have track spin a rut when I land. I also find that when I hammer the throttle, there is a launch affect, therefore if you hammer the throttle then slam the brakes, you've got to first overcome the acceleration before the deceleration can take place.

REXX
----------------------------------------
Western Canada
'07 Apex mtn SE turbo

 

[REXX]

Here's a thought. Are you sure it's just not your turbo still powering you? Also,with turbo you've got a lot more track spin to contend with therefore a lot more forward mometum track mass to slow down. Yamaha designed the brakes for 150 hp. not 250 - 350hp.

I run 16 lbs. boost. I've done jumps where I let off the throttle in mid air, but still have track spin a rut when I land. I also find that when I hammer the throttle, there is a launch affect, therefore if you hammer the throttle then slam the brakes, you've got to first overcome the acceleration before the deceleration can take place.

REXX
----------------------------------------
Western Canada
'07 Apex mtn SE turbo

 

[HYFLYR]

The turbo should not have any effect on your brake lines, not with the impulse at least, unless you have the brake line in the wrong place. Bd turbos had trouble with this but because the header was right under the brake line and impulse is a foot away from the brake and lines.

Did you check your pads?

Are you closing the valve as your pushing out fluid when bleeding the brake? if not then you can get air in your line and brake fade will occur.

I havent had any brake problems on the impulse kit as of yet but i will keep an eye out.

 

[Tookes]

Thanks guys for the help I will be double checking all your ideas. Rexx, I understand what you are saying, it happens at the crest of a big pull, I let off the throttle at the top to drop the nose and turn it around and still have to pump twice. ??? Thanks again guys!

I might have to call my turbo expert over to check it out..... hint hint Hyflyr

 

[MotoPsycho]

Sounds to me like a warped rotor, or loose caliper. If it is warped or the caliper is loose, the back and forth motion will push the piston back into the caliper far enough that one stroke of the lever will not push enough fluid to the backside of the piston to engage the pads.

Generally, if the fluid is boiling, and causing air bubbles in the system, it would take more than 1 stroke of the lever to pump it up again...

 

[HYFLYR]

exactly what i was thinking but i wanted to avoid the worst.