THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Tjerk

The item 35 you mention (part # 7103366220 ) is a static pressure valve, and according to my spare parts catalogue from 1985 two of them are used for 4x4 as well as 6x6 trucks.
They are identical thus interchangeable.

The valves are displayed on the page for the master brake cylinder; I posted the piping layout to visualize my previous explanation.

The piping to the rear axle of the Austrian version contains a block numbered 130.02.04, this is the proportional adjustment for braking strength on the rear axle
Increased weight on the axle raises the brake force in order to prevent blocking the wheels


Details of that are shown here



Nevertheless we should focus on what is possible to diagnose in the jungle.

• you can swap brake drums and shoes from front to rear

• you can disconnect brake lines to verify how far pressure is built up towards the rear axle

• get yourself a manometer with an adapter for the brake lines and measure the pressure at all positions you can disconnect the plumbing

that should get you closer to the core of the issue

Albert
The complaint was that the rear brakes were lacking in stopping power thus the adjustment of link 13 to the proportional load sensor should solve his problem.
I doubt if the manual describes a how-to without a rolling brake tester.
The link has to be lengthened/shortened till the rear brakes lock up when road tested and then backed off a few turns.
Tjerk

Tjerk

He has a swiss setup, and therefore no proportional valve on the rear ....