I went for a vehicle inspection. It turns out that the handbrake isn’t working properly. The left rear brake is very weak, while the right one is fine.

Is it possible to adjust just the faulty one? How can I do that?

The handbrake engages too high. I don’t want to adjust it with the screw inside the car because that would tighten the right drum too much.

Help :)

On the MK1 fabia which I am sure will be the same or similar on yours there are slider wedges that automatically adjust in rear drums. They can seize or wear out. They have a gripped surface on one side and are held in place with a small spring.

It could also be a failing brake cylinder or leaking cylinder and contaminated shoes or a sticking handbrake cable on the poor side. If the handbrake is high it would point to the adjuster not working. Either way they will need to be taken apart to check.

Alasdair

The main foot brake works fine. The braking force from the foot brake is OK.

The top end pivot will be seized on the plate of steel in the drum that the handbrake cable attaches to.

How can I adjust or repair it? What needs to be replaced?

You might be able to free it up if you take that drum off, disconnect cable from that plate then rotate it back and forth to break corrosion.

Add a few drops of oil to the pivot/rivet, between the plates.

Loosening the cable adjustment in the cabin by quite a lot is a big help when trying to remove drum. Retighten when work is done.

Red ring is the pivot that often seized. Pink arrows show the movement which should be free and easy.

Green arrows shows the adjuster which Alasdair mentioned.