Ok...so I go to bleed the brakes,all new stuff,jaybrake 2 piston caliper(rear brakes)with a new master cylinder....and a 46" braided line and I have no problem bleeding them but the back wheel doesnt spin like it ought to....the brake pads are rubbing against the rotor....I go to bleed the line,close the bleeder valve....spin the back tire....she spins freely.I hit the brake peddle ONE TIME!!!!! and the wheel tightens up[&o]...is it the flexible line?I've never encountered this problem before!!!

 

well we seem to have a rash of these
read some of My other posts on trouble shooting brake issues. But if every things is new check you free play in the linkage

 

Ribcracker...here's what I did....a repeat of everything I did yesterday!!All jokin aside,NOTHIN has changed after changing washers,making sure all the fittings were tight,Every component associated with the back brake/rotor assy. is new.....There's just one thing that makes me think twice about this....The master cylinder is for older style harleys with drum brakes.
Is it possible that these master cylinders were designed to maintain residual pressure to make it easier for drum brake use?

I called Jaybrake today and they didnt have a clue as to what to tell me.....except that they wanted me to use their master cylinder..............Whats your opinion here?

 

there should never be any build up of pressure once the brake pedal is released. On a drum system the shoes are either manualy adjusted for clearance or there is some form of auto adjustment.
Right lets trouble shoot this.
One thing I noticed you didnt mention was making sure there was free play in push rod from the pedal to the master cylinder. Make sure the pedal isnt sticking and is returning fully.Ifit does is there any slack/free playthere.Next undo the lock nut on the master cylinder end of the rod and then wind the collar where the rod screws in further onto the shaft then see if it releases if not wind it the other way till the rod is out and try again. You can use a screwdriver pushed into the end of ther to operate the master cylinder. Seeing as you dont need much leverage to just move the pads. If this doenst make any difference its down to the fluid side.
We need to make sure this is a case of the presure build upafter you release the brake or is it that its down to the pads binding in the caliper.
Take the caliper offand slide a piece of wood between the pads.Press the pedal to push the pads out a little. and see if you can push them back. If you cant push them back, crack the bleed nipple. If they go back itspressure build up if not its the padsor the pistons binidng.
If its the pads take them out and try it again with justthe psitons.Check the pads for signs of rubbing agsint caliper and also check the caliper for marks or burs.
Ifits pressure we now need to work back from the claiper to find out wherethe faultis.
Wood back in press the brake, this time crack thebanjo bolt on the caliper.If the pads still dont return pull the bolt and make sure there isnt any dirt or maybe a bit of swarf left thats stoing the fluid returning. If the pads go back, tighten the bolt and work down the line to the next union,which is probably the brake light switch, do the same for each union till you get back to the master cylinder. Ifthe pressure releases when you losen the bolt on the master cylinder, then it is a probelm with the master cylinder. Again check for dirt or swarf.

I know this is a lot to do but it will isolate where your problem is ratehr than just throwing bits at it blindly. I hate bleeding brakes as no matter how carefull you are the damned fluid always gets soemwhere you didnt want it

 

Yo RIB...I got it man!! I removed the wrong stuff out of the master,Ya gotta remove the little thimble shaped valve with the holes in it...AND the rubber washer with a hole in it which is located up front before the spring,put 'er back together again and back bleed it....................She worked on the first pump of the brake pedal!!!! No dragging on the rotor,just workin the way she oughta!!!

Thanks for your information and time!!!

 

no worries glad you got it all sorted, now saying you had rebuilt the master cylinder rather than just saying it was new Might have helped as well