bleedin brakes

just got bike built and onto road but brakes feel full of air. I tried
bleeding them but the tube going into the jar of DOT4 never has any air in
it but the brake lever doesn't get any stiffer.
where am I going wrong the master cylinder is pumping fluid (clear without
bubbles) but only gets any feeling if I very,very slowly release the lever
after releasing the pressure at the calliper.
do I have to do both callipers at once or do I release the pressure at the
bango on the master cylinder to check for no air.
someone suggested draining the system and starting afresh. is this good
advice.

Robin

 

I know this may sound a bit too obvious, but it was a new pot of brake
fluid? Your master cylinder may be shot. If I remember correctly some
portion of mine gets replaced every 12,000 miles. Your bike may require
doing the left side first, or of course the right first, but it'd
probably help to tell us all which bike this is.

 

yes , check for any leaks first though around the seals , completely change
the fluid pumping it through (use a new tin of whatever specified in your
handbook)

squeeze the brake lever in quickly and release slowly , try tightening the
nipple before you release the brake and loosen again before you squeeze
again once your sure no more air is in the system retighten bleed nipple
keeping the brake lever squeezed in tape it in this position overnight this
helps to remove any air out of the brake line

make sure when bleeding your brakes that no air is being sucked in through
the plastic pipe or the bleed nipple

 

sorry but its a Y2K R1 with only 3500m from new but only 52m from a rebuild
after a spill that I had 6 months ago. I'm going to try removing the
callipers and check they're free enough and have another go at bleeding the
buggers. I read somewhere about checking if the hoses stiffen or not under
pressure how or when do I check this.

Robin