An operating permit is available for the brake system of the vehicles. This licensing becomes invalid if the brake system is
modified.
Load-related brake proportioning valve
(only for front-wheel drive)
The load-related brake proportioning valve is conceived for adjusting the brake pressure at the
rear axle to the respective load condition and is controlled according to the spring suspension
at the rear axle.
The load-related brake proportioning valve is provided ex-works with a regulation, based on a
tension spring, relating to the unladen weight of the vehicle. Usually, it is not required to
re-adjust this regulation - not even after mounting an attachment onto the chassis.
In special cases - for example retrofitting of reinforced springs, mounting of an unusually
lightweight attachment - it is required to correct the regulation of the brake proportioning valve.
The pressure check and regulation should be carried out at a Volkswagen dealer/workshop for
utility vehicles. The regulation has to be performed in such a way that the balance beam is
horizontal.
Modifications of the brake system are illegal!
Exceptions are the adaptation of the brake-pressure line and the handbrake cable in the
scope of wheel base changes at chassis.
Volkswagen AG
Automatic brake pressure regulator
Check:
Inlet pressure on front axle
wheel cylinder bleeder valva
Mean value from left
and right
Test:
Outlet pressure on rear axle
wheel cylinder bleeder valva
Rear axle load
(kg)
Input pressure
(bar)
Output
pressure
(bar)
500
600
650
700
750
50
50
50
50
50
14±2
14±2
15±4
19±5/2
24±6/4
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