HU – Brake power 2nd axle too low. Is it the brake force controller?

The car is an older Suzuki Wagon R WITHOUT ABS. The braking force on the rear axle (drum brake) was too low; I changed the cheeks and it didn’t really improve. I don’t think the rear axle blocks on the test bench. From HU I have numbers, left right 1st axle 203 161 2. axle 63 51 Handbrake 123 91 With new brake cheeks it was not much better today in the hobby workshop, especially it did not lift the rear axle out of the roller test bench. Unfortunately I was not allowed to “driving” him, but both at the HU as well as in the hobby workshop, according to demand was maximum. However, at the hobby workshop he was loaded with approx. 50kg in the trunk and I am briefly also on the loading edge with my 95kg, but no change. In 2012 the test report for the dealer (in my opinion after a fall investigation) was similar from the values. At the front each 200, at the rear at the service brake each 60 and allegedly blocked. Reports from the previous years In between, unfortunately, we don’t have. In total, 4 cables go into the controller, it has its own internal control piston for each side. Since the brake force regulator reacts to the axle load or suspension of the rear axle, I wonder if this is not even correct, because it is supposed to limit the braking force on the rear axle. It is set by shifting the beginning of the spring on a guide on the rear axle, the setting is correct. We are far away from 50% of the minimum braking, 1330kg would be the maximum permissible mass but perhaps there are other criteria for such vehicles with load-dependent brake force regulator.