Recently, I did rear shoes and wheel cylinders, cleaned drums thoroughly with brake cleaner, and since then, the rear drums lock up. Example, if you are pulling into the garage and tapping the brakes, the first tap might not lock, but the 2nd and so on do lock up. It seems to not be releasing the hydraulic pressure after initial braking. I've read a ton of posts here and never found a definate answer. BTW, I did the rear rubber hose and bled them again, with no change. There are no ABS or brake lights on dash!

1) master cylinder?
2) proportioning valve? stuck...replace?
3) replace drums?

TIA

 

Had my wheel cylinders done, the rears gave em problems. They changed the wc again just to be sure. One issue is the adjusters are not offset and if you put them in backwards they lock the brakes. So sayith the mechanic. After issues with disks I gave in to the drums. Glad it wasn't me chasing the problem.