No braking force

Hi guys. I have a 2004 Jimny Sa(n)tana with ABS. No issues so far, but it failed Inspection recently due to low braking force on rear axles. I changed already the calipers, drums, liquid, central pump, then proportioning valve.... no change. The car brakes ok, no issues on the road but the force is not higher than 46% on the rear brakes. Clueless what to do next.
Any ideas are welcome

Welcome to the forum. The 46% is that equal across the axle, at both wheels? I'm trying to remember what I had on my last test and I seem to think it was something like 350kg to 400kg on each front wheel and about 120kg to 150kg on each rear wheel and that was considered good. What I am saying is I'm surprised that 46%rear breaking efficiency is failing a test simply because the breaking system of all cars is designed specifically to put most effort into the front brakes so that stability is maintained. As you brake weight is transferred to the front of the car so having too much braking effort at the back will cause the rear wheels to lock and slide.

What level is your testing centre wanting for a pass?

Also have you changed the flex pipes there's one on each front and one for the back axle it is possible they have failed internally.

Well, Indint know the details regarding the requirements, and I am a brand new Jimny owner.
Anyhow, I found a donor abs modulator, I ll ask the workshop guys to change that too, amd see what happens.
It is weird, because the front axle brakes are perfect, and the rear handbrake is also working great. I ll try also the flexible pipes as recommended below.
If there will be no option, I ll have to take it to a Suzuki dealer service, but that is really expensive here.
Thanks for the tips.

Abs shouldn't be affecting the brake effort at the rear wheels if it's getting 46%. Again I am concerned that 46% effort is considered inadequate?

Yes, it was inadequate, and it didn t pass the inspection. I ll ask tomorrow for the test sheet at the workshop to be sure regarding the figures. The test result was with 4-5% below the minimum legal requirements.