Hydraulic System - Opel Zafira B MPV 2006 Owners Workshop Manual

9•2 Braking system
Torque wrench settings
Nm lbfft
ABS hydraulic modulator mounting bracket bolts ................ .
20
15
ABS hydraulic modulator to mounting bracket .................. . 8 6
Brake caliper bleed screws ................................. . 10 7
Brake caliper guide bolts:
Front caliper . . . . . . . . . . . . . . . ........................... .
28
21
Rear caliper . . . . . . . ................................... . 25 18
Brake caliper mounting bracket bolts ......................... .
100
74
Brake fluid pipe unions ..................................... .
14
10
Brake hydraulic hose banjo union bolts. . . .................... .
40
30
Brake pedal mounting bracket bolts/nuts . . . . . ................ .
20
15
Handbrake lever retaining huts . . ........................... . 10 7
High-pressure fuel pump mounting bracket bolts ................ . 25 18
Master cylinder retaining nuts:
1.6 and 1 .8 litre petrol engine models . . . . . . . . . . . . . . . . . . . . . . .
15
11
2.2 litre petrol engine models . . . . . ...................... .
21
15
Diesel engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . 21 15
Roadwheel bolts ..................................... .
110 81
Vacuum pump mounting bolts:*
Stage 1 ............................................ ..
6
4
Stage 2 .............................................. . Angle-tighten a further 50"
Vacuum servo unit mounting nuts ............................ . 20
*
Use new fasteners
1 General information
The braking system is of servo-assisted,
dual-circuit hydraulic type split diagonally. The
arrangement of the hydraulic system is such
that each circuit operates one front and one
rear brake from a tandem master cylinder.
Under normal circumstances, both circuits
operate in unison. However, in the event of
hydraulic failure in one circuit, full braking
force will still be available at two wheels.
All models are fitted with front and rear
disc brakes. The disc brakes are actuated
by single-piston sliding type calipers, which
ensure that equal pressure is applied to each
disc pad.
An Anti-lock Braking System (ABS) is fitted
as standard equipment to all vehicles covered
in this manual. On higher specification models,
the ABS may also incorporate traction control
or an electronic stability program. Refer to
Section 17 for further information on ABS
operation.
The cable-operated handbrake provides an
independent mechanical means of rear brake
application.
On diesel engines, since there is no
throttling as such of the intake manifold, the
manifold is not a suitable source of vacuum
to operate the vacuum servo unit. The servo
unit is therefore connected to a separate,
engine-mounted vacuum pump bolted to the
left-hand end of the cylinder head and driven
by the camshaft.
Warning: When servicing any
part of the
system,
work carefully
and methodically; also observe
scrupulous cleanliness when overhauling
any part of the hydraulic
system.
Always
renew components (in axle sets, where
applicable) if in doubt about their condition,
and use only genuine Vauxhall/Opel parts,
or at least those of known good quality.
Note the warnings given in 'Safety first!'
and at relevant points in this Chapter
concerning the dangers of asbestos dust
and hydraulic fluid.
2 Hydraulic ,,,.,.,,i,,,,. ....
bleeding
Warning: Hydraulic fluid is
poisonous; wash off immediately
and thoroughly in the case of
skin contact, and seek immediate medical
advice if any fluid is swallowed or gets into
the
eyes.
Certain types of hydraulic fluid
are inflammable, and may ignite when
allowed into contact with hot components;
when servicing any hydraulic system,
it is
safest to
assume that the fluid is
inflammable, and
to
take precautions
against the risk of fire as though it is petrol
that is being handled. Hydraulic fluid is also
an effective paint stripper, and will attack
plastics; if any is spilt, it should be washed
off immediately, using copious quantities
of fresh water. Finally,
it
is hygroscopic (it
absorbs moisture from the air) - old fluid
may be contaminated and unfit for further
use. When topping-up
or
renewing the
fluid, always use the recommended type,
and ensure that it
comes
from a freshly-
opened sealed container.
General
1 The correct operation of any hydraulic
system is only possible after removing all
air from the components and circuit; this is
achieved by bleeding the system.
2 During the bleeding procedure, add
15
only clean, unused hydraulic fluid of the
recommended type; never re-use fluid that hes
already been bled from the system. Ensure that
sufficient fluid is available before starting work.
3 If there is any possibility of incorrect
fluid being already in the system, the brake
components and circuit must be flushed
completely with uncontaminated, correct fluid,
and new seals should be fitted to the various
components.
4 If hydraulic fluid has been lost from the
system, or air has entered because of a
leak, ensure that the fault is cured before
proceeding further.
5 Park the vehicle
over
an inspection pit or on
car ramps. Alternatively, apply the handbrake
then jack up the front and rear of the vehicle
and support it on axle stands (see Jacking and
vehicle support). For improved access with the
vehicle jacked up, remove the roadwheels.
6 Check that all pipes and hoses are secure,
unions tight and bleed screws closed. Clean
any dirt from around the bleed screws.
7 Unscrew the master cylinder reservoir cap,
and top the master cylinder reservoir up to
the MAX level line; refit the cap loosely, and
remember to maintain the fluid level at least
above the MIN level line throughout the
procedure, otherwise there is a risk of further
air entering the system.
8 There are a number of one-man, do-it-
yourself brake bleeding kits currently
available from motor accessory shops. It is
recommended that one of these kits is used
whenever possible, as they greatly simplify the
bleeding operation, and also reduce the risk of
expelled air and fluid being drawn back into
the system. If such a kit is not available, the
basic (two-man) method must be used, which
is described in detail below.
Caution: Vauxha/1 recommend using a
pressure bleeding kit for this operation
(see paragraphs 24
to
27).