alright let me preface this by saying i am not an idiot...(some may disagree, but i am not)...

i just put on my SS lines and my powdercoated calipers (which are not f'd to some degree)....

i went to finally re-fill and bleed my brakes this weekend and it was a f'ing disaster....i have learned a few things and am still stumped about others...now i have never done brakes before but i have read about 1000 tutorials on it so i thought i had it pretty much down....but this is how it went this weekend...

first did the rear....hooked up the mityvac to the bleeder....created some preseure...had my buddy start filling brake fluid...within a matter of about 30 seconds...i was pulling clean fluid....closed the bleeder....topped off the res...pushed the rear brake lever (althought a little soft), brake engaged...was up on the rear stand at this point...thought i was done....left it alone...went to front...

front...HORRIBLE....anyways....started to prime the right...could NOT get pure fluid without bubbles...after 30 minutes...gave up....closed the bleeder and went to the other side....there....30 seconds and nice pure dot4 coming out of the mity vac...closed up the bleeder....went back to other side...STILL FRICKIN BUBBLES....after about an hour...realized that the bleed screw must be letting in air...went and got some teflon tape....put it around the bleeder threads and screwed it back in....HUZZAH!!! suddenly i could maintain vaccum and got a nice smooth flow pulling out of the caliper....

now here's the crappy thing...i THINK i know what it is going on but i need confirmation and/or guidance...

now...even though i got bubbless fluid pulling from the bleeders....i squeeze the lever and there is NO...i mean NO pressure....after trying to figure out what the hell is going on...my buddy and i chatting...i start squeezing the lever a bunch and it is slowly getting firmer...then i realize...because i had the calipers powdercoated...the pistons were seated all the way back into the calipers....so i think i had to get them back out agains the pads and rotors....so i keep going and sure enough after what seems like a million pulls....i have a LITTLE front brake...not nearly enough to stop the bike but if the wheel is free spinning on a front stand, the front brakes can stop it...on the ground...no dice...

at this point, i have been at it for 3.5 hours and am pissed...i take the bike off both stands (had it off the front for the front brakes, just FYI)....and move onto something else...now the rear brake whihc i thought was fine turns out it doesn't have much power either when actually on the ground...GREAT!....but i think i just need to pump it like i did the front...i never did it to the rear....

what i think i have learned is that the M/Cs only displace a very little amount of fluid and therfore to get the pistons out of the calipers to where they need to be takes quite a bit of pumping....i HOPE i am right....

what do i next? i did this on sat and let it sit on sunday...i am assuming i should redo the process and re-bleed....i haven't tested the levers to see if they got any firmer yet...i will tonight...

does anyone have any thoughts or comments....i was seriously ready to kick the damn thing over...luckily i moved on and installed some of my LED lighting which looks kick *** so that saved the day..

thanks guys, appreciate any guidance...

 

Never used the mityvac thingy, if it was just the one brake that's doing this I'd say it you had a rooted master cylinder, since thats not the case......
I've always used just clear PVC tubing & a jar to bleed/replace brake fluid, only fancy thing I've ever used was an attachment with a one way valve, but that was eons ago.
Couple of things, are you bleeding into a jar (or whatever) immersed in brake fluid?
When you pump the brakes, are you holding the lever in when you tighten off the bleed valve?
Are you topping up the brake reservoir as you go & not letting it pump air?
Twin disc at the front have always been a strange one, since basically their only using the one hose, with a two way adapter, but you always get different results on each bloody one.

OK, when a brake won't pump back up, means you either have a stuffed M/C or you have air in the system, if the brakes where ok (as in working) before, then the powder coating would make stuff all difference. Good luck

Oh, one last thing, just be aware of the amount of force your using to close off the valves, the taper at the end is very fine & can be blunted with excessive (read :enthusiastic) tightening & won't seat properly. If you suspect this could be the case, get some newies, as their cheap enough.

 

the mityvac thing actually worked really well...i just think the bleed fitting was letting in air as once i used a little teflon tape, there was no issue...

i am using a clear tube, but with the mityvac..the one i have has a vaccum gauge...meaning i can check if there is vaccum on the bleeder...so i am about 95% sure that air is not getting in through the bleeder once the vaccum is set up and pulling fluid....like i said, i am getting pure fluid from the bleed with no bubbles...as for tightening the bleed with the lever squeezed..yes, i am doing that, but like i said the pressure is very weak...

like i said i replaced the lines with SS lines so i am not on a split line system anymore, i have two separate hoses to each caliper...so i know that isn't an issue...and like i said, i got pure fluid from each caliper at each bleeder...

i don't think i have a M/C problem as squeezing the lever a few (what feels like) a thousand times did firm up the lever a bit...

my issue that i think i am having is because i had the calipers powdered...the pistons got pushed flush back into the caliper....therefore they need to re-position themselves to put pressure on the pads and thus the rotors...

when most people are bleeding, the calipers don't need to be reset as the pistons are not being forced back into the caliper...now consider that with the fact that the M/C forces small amounts of liquid into the lines (at least from what i can tell) it would take quite a bit of pumping to get the pistons to where they need to be...at least, that is what i am thinking...

i am going to check them today to see how firm the lever has gotten, if at all....what i am thinking is that i will need to keep squeezing the lever for a bit more until things get somewhat firm, then try to re-bleed again...thus bleeding them with the pistons in the caliper in the right position..

do i sound nuts with my logic?

 

No, your logic is fine, like any problem, you just follow the most probable path. & as Murphy says "Anything that can go wrong, Will go wrong & at the most inconveniant time") When I replace my pads, I push them against the pistons & force them back into the caliper so they clear the disc, & this makes no difference when I reapply the brake (it's weak till the pads hit the disc & pressure builds up).
If you think you have a ****ty valve adjuster(s), then off to the shop with ye laddy & get some new ones.

 

yeah...i don't think the adjusters are bad....dunno...

as for a couple things...i think if you push the pads back and thus the pistons when changing the pads, you are maintaining a lot of pressure that was already there thus needing less to get them back to "normal"...what i mean is that the since the M/C is still sealed, the system is still under pressure....versus when you are trying to fill it, you have to 'build up' that pressure...i don't know if that makes ANY sense...makes sense in my head [&:]....

i think my downfall was not considering the fact that i would have to get the calipers pushed out and seated against the rotors....i was essentially priming and bleeding the calipers with them pushed all the way in...the vaccum nor the lever were going to make them "pop" back into place, i need to work the lever to get them in place so i have the right volume of fluid in the system...

it makes sense because with the bleeder screwed shut....as i pumped the brake (when they were squishy and NO braking at all)...the fluid slowly drained telling me the pistons were moving and filling the cavity behind the pistons...i slowly added more and the brakes SLOWLY began to have some power....that is where i am at now...with a LITTLE braking power, but not nearly under the pressure it needs...

i think i just need to be patience and continue to work the lever until they are seated as far as i can, they re-bleed the system....then all should be fine....

it's amazing what you learn when you are doing something for the first time...[&o]

 

try bleeding the M/C, you may just have some air stuck in there, Its never been an issue on my F4i but I have to bleed my SV's M/C every time to get all the air out

 

you know, i read about bleeding the M/C....how the heck do you bleed the M/C??

it would make sense since i bled the whole damn thing dry to take off the lines and calipers...is it easy?

 

just squeeze the lever and loosen the banjo bolt going into the M/C, let a decent bit of fluid come out and close it, not the prettiest way to do it but it works. Make sure you don't let brake fluid drip onto your front tire or brake rotors, a nice big rag is a good idea

 

huh...alright...then i am assuming...re-torque the banjo...it isn't going to screw with crush washers will it considering i already torque it down once? i wouldn't think so, but at this point, i want to know what i am getting into...haha...

 

they'll be fine, I've done it many times