i had trouble getting my e-brake working correctly on my 69 charger when i installed replacement cables because the originals were completely rust frozen due to not being used.
as it turned out, i had to add a small section of spring to the driver's side cable where it is inside the drum, attached to the apply lever.
also, i had to re-rout the passenger side cable because routed in the factory location, it bound up and wouldn't release.
and finally, as a "help", i installed a return spring at the cable mounting point on the driver's side frame rail, which attaches to the main cable bracket that hooks both cables together at the adjustment screw end of the main cable.
the e-brake works as it should now, smooth to apply and release, as well as holding the car stationary on a sloped surface without being in park.
dorman was the cable brand i used, so i don't know if my "fixes" only apply to this brand or not.
just my personal life experience fixing my e-brake.
your mileage will vary.
