brakes locking up

[cheffry]

Howdy!  Cheffry here, my '73 Indian's rear brakes start to get real tight after driving for a while.  If I stop and open the bleeder valve i get a good squirt and then they are fine for another 50 miles or so.  Any ideas?

[The_Handier_Man1]

Hey Jeff,
Sorry to hear about the brake problem but it reminds me of this discussion http://www.classicwinnebagos.org/index.php?option=com_smf&Itemid=43&topic=1023.msg1041#msg1041.  That's when a member, who sold brake parts, said I needed his $350.00 master cylinder instead of the $25.00 one I put in.  Well for the record I have used the wrong MC for 6,000 miles without any thought of a problem.
But back to your rig, does it have front disks?  Have you changed anything with the brakes? Did it just start this after working fine?.....Les

[ntsc358]

had a similar problem with my big truck- replaced master cylinder twice- both ft hoses and right ft caliper(one locking up twice. turned out  the left rear was leaking and did not have enough vacuum in the system to pull caliper back in
Does the cap on the master have a rubber gasket and have you checked it when this happens - mine tried to suck it into the master cylinder (no longer flat - it inverted the gasket?)  if only one is locking up check the rear on the other side

[Chuck]

Are you sure that it is both rear brakes locking up?  If not, it could be a slave cylinder freezing up.