From model '83
REMOVING AND INSTALLING
BRAKE MASTER CYLINDER

Description:
Operating the brake pedal will move pistons (1 and
4) forward.
Primary cups (2 and 5) will pass over compensating
bores (3 and 6).
There will now be balanced pressure in chamber
A and B.
Diagonal Dual Circuit System
Chamber A acts on front right and rear left.
Chamber B acts on front left and rear right.
Brake pedal travel will increase considerably, if
one brake circuit fails.
If second circuit fails, piston (1) will use the
pressure building up in chamber A to push piston
(4) in pressureless chamber B against tandem
master cylinder housing and the first brake circuit
resumes Function.
If the first brake circuit fails, piston (1) in pressureless
chamber A will be pushed against spring loaded
cap (7) and the second brake circuit will
have full action via chamber B.

Draw off brake fluid through tank with a syringe
used exclusively with brake fluid.

Disconnect brake lines.
1 Front right
Rear left = 1st brake circuit

2 Front left
Rear right = 2nd brake circuit
Installation: Tightening torque¹).
Bleed brakes 34 00 046.


34 00 046

Detach tandem master cylinder at brake booster.
Installation: Tightening torque¹).
When replacing, make sure new master cylinder
has correct diameter¹).