rear drums: uneven braking problems

[ownor]

Hi guys, i just had my 89 formula inspected and they found my rear brakes to be quite uneven, values below are all in kilonewton. driver side | pass side foot brake: 0.7kN | 2.5kN e-brake: 0.6kN | 2.0kN i had the same problem last year and i put a new wheel cylinder in the driver's side drum and new pads on both sides which fixed it, that's maybe 2k miles ago. but lately i've noticed that at low speeds and low brake pedal pressure the right rear tire sometimes blocks, obviously because the left one doesn't brake a whole lot at all... the lines seem to be okay and the distributor T-fitting rarely fails, i suppose. oh and yes i have read the brake 101 sticky any other ideas? maybe the cylinder is sticking or the return spring came loose or something.. btw i don't have any (external..) leaks. thanks for any comments and hints guys i wont drive the car now as i wont have time to look at this issue until next week, so i'm gathering some ideas.