Assembly overview, ABS/EDL/TCS/ESP Bosch 5.7 - hydraulic unit, brake servo/brake master cylinder — VW

VW
Passat
1997
Running gear
Protect brake systems
Edition
09.2004
Assembly overview, ABS/EDL/TCS/ESP Bosch 5.7 - hydraulic unit, brake servo/brake master cylinder
Tandem brake servo
On petrol engines the vacuum required is taken from the intake manifold.
Vehicles with a petrol engine and an automatic gearbox are equipped with a brake vacuum pump
Chapter
.
Functional check:
With engine switched off, depress brake pedal firmly several times (to exhaust the vacuum in the unit).
Now depress brake pedal with average foot pressure, hold and start engine. If the servo unit is working properly, the pedal will be felt to give slightly under foot (servo assistance becomes effective).
If faulty, renew complete.
With bonded seal.
Removing and installing
Chapter
.
Brake line
Brake master cylinder/primary piston circuit to hydraulic unit.
Marked on hydraulic unit with
“HZ1”
Brake line
Master brake cylinder/secondary piston circuit to hydraulic unit.
Marked on hydraulic unit with
“HZ2”
Brake line
To front left brake caliper.
Marked on hydraulic unit with
“VL”
.
Brake line
To front right brake caliper.
Marked on hydraulic unit with
“VR”
.
Brake line
To rear right caliper.
Marked on hydraulic unit with
“HR”
.
Brake line
To rear left caliper.
Marked on hydraulic unit with
“HL”
.
Brake pressure sender
Removing and installing
Chapter
.
ABS hydraulic unit
Control unit
Locking clip
Buffer
Retainer
Allocation
Electronic Parts Catalogue
.
Hexagon bolt, 9 Nm
Sealing ring
Tandem brake master cylinder
Cannot be repaired. If faulty, renew complete.
Removing and installing together with brake servo
Chapter
.
Self-locking nut, 49 Nm
Torx socket head bolt T45, 25 Nm
Brake fluid reservoir
Cap
Sealing plug
Moisten with brake fluid and press into brake fluid reservoir.
Trunnion bolt, 10 Nm
Vacuum hose
Insert into brake servo unit.
Connecting brake lines from tandem brake master cylinder to hydraulic unit
A
Hydraulic unit to brake master cylinder primary piston circuit.
Marked on hydraulic unit with
“HZ1”
B
Hydraulic unit to brake master cylinder secondary piston circuit.
Marked on hydraulic unit with
“HZ2”
1
Hydraulic unit to front left brake caliper.
Marked on hydraulic unit with
“VL”
.
2
Hydraulic unit to front right brake caliper.
Marked on hydraulic unit with
“VR”
.
3
Hydraulic unit, rear right brake caliper.
Marked on hydraulic unit with
“HR”
.
4
Hydraulic unit, rear left brake caliper.
Marked on hydraulic unit with
“HL”
.