seat Workshop Repair Guides

SEAT Workshop Service and Repair Manuals

Master brake cylinder: removing and installing > < Changing brake fluid
Assembly diagram: Brake servo / Master brake cylinder:
   
Assembly diagram: Brake servo / Master brake cylinder:
  Note!
The master brake cylinder and the servo brake can be replaced independently.
1 - Brake servo
q   In petrol engines, the necessary vacuum is taken from the intake manifold
q   In diesel engines the necessary depression is generated by a vacuum pump
q   Vacuum pump: removing and installing → Chapter
q   Checking functioning:
q   With engine off, strongly depress the brake pedal several times (this reduces the existing vacuum in the aparatus)
q   Next, keep the brake pedal depressed halfway and start engine. If the servo brake is working correctly the brake pedal will give way noteably (the servo brake effect is beginning)
q   If faulty, completely replace
q   Brake pedal: separate from brake servo → Chapter
q   Brake servo: removing and installing → Chapter
2 - Brake fluid level switch
3 - Cap
4 - Brake fluid deposit
5 - Union plugs
q   Moisten with brake fluid and insert into the brake fluid deposit
6 - Securing pin
q   Insert through the master cylinder
7 - Hexagon nut
q   20 Nm, self-locking
q   Replace after removing
8 - Brake master cylinder
q   Repairing is not permitted. If faulty, completely replace
q   Removing and installing → Chapter
9 - Vacuum hose
q   Insert into brake servo
q   Check non return valve in the vacuum pipe → Fig.
10 - Union plugs
q   Renew if damaged
11 - Oil seal
q   Renew
12 - Gasket
q   For brake servo
13 - Hexagon nut
q   20 Nm, self-locking
q   Replace after removing
q   4 units, to secure support block to servo brake
14 - Bellows
q   Make sure it is correctly fitted otherwise there may be admission noises

   
Non-return valve -A- in the vacuum hose: checking
The valve should allow air to pass in the direction of the arrow.
The valve must close in the opposite direction.
Note fitting position, arrow pointing towards the engine.
  N47-0048

Master brake cylinder: removing and installing > < Changing brake fluid