Front Brake pad replacement and intermittent brake pressure

[Yellow99]

Just finished replacing front brake pads on 99 standard. Removed some fluid from reservoir to allow pistons to be pushed in. Installed new pads and topped off reservoir.  Pumped up brakes which felt solid.  Then moved Bike back and forward and lost pressure,pumped up again and had good pressure, moved bike back and forth and lost pressure again.  Any ideas? I will bleed tomorrow however I have good solid pressure until I back the bike up then I loose pressure until I pump back up.  Sorry for going on. Can the reservoir be over filled?

[ricoman]

bleeding will likely provide the cure.
I recently installed speed bleeders and the install isn't supposed to allow air in-it did so I did bleed them. And-the spped bleeders worked great.
Sometimes when you take fluid out you think all will be OK, then Murphy's Law comes into play.

[Yellow99]

FYI, Im an idiot.  Somehow I installed one of the pads incorrectly which caused the pad to slip out of position and pistons to almost extend out of caliper. which caused air in hydraulic system. Test drive revealed scraping noise which distroyed one of the new pads.  Now waiting for new pad set and lesson learned.

[Patrick]

Bleeding shouldn't be necessary for just a pad change.. How much fluid did you remove from the cylinder??  From your last post I'm wondering if you know how to bleed.. Its really easy, but, you'll need really long arms or someone to hold the lever for you.. You don't need speed bleeders.. Make sure there is enough fluid in the cylinder, pump the handle/lever a few times and hold pressure on it. Open bleeder, close bleeder, release lever and repump and hold lever again.. Keep repeating until you see no air bubbles.. Start at far end of the system and work your way back..Don't release the lever until the bleeder has been closed.. Don't let the cylinder become dry/empty while doing this or you'll have to start over.. Yes you can put too much fluid in the cylinder reservoir but I doubt this is your problem..

[MarkT]

I picked up this power-vacuum bleeder from Harbor freight.  Bleeds brakes easily or replaces all the fluid,  without a 2nd set of hands.  Does not allow the reservoir to go dry.  Works great, only $25.
http://www.harborfreight.com/brake-fluid-bleeder-92924.html

[olddog1946]

You may have indeed caused a bigger problem than an improperly installed pad..If that piston came out far enough to lose the seal, bleeding will not fix your prolem..your system has air in it and could be sucking in air or just have air left in it...be sure and double check that caliper for leaking...if none, bleed.
If it is leaking, repair the caliper, then bleed.

BTW, the only person I ever met that never made a mistake was the one that never did anything.

[Bobbo]

BTW, the only person I ever met that never made a mistake was the one that never did anything.

 

I have not failed. I've just found 10,000 ways that won't work.
               -Thomas Edison