rims FIAT 500 1971 1.G Workshop Manual

FIG 10:1 Diagrammatic view of service and rear wheel parking brake system
Key to Fig 10:1 1 Bleeder connections 2 Brake fluid reservoir 3 Service brake pedal 4 Hand lever, mechanical
parking brake on rear wheels 5 Hand lever travel adjustment stretchers 6 Stop lamps 7 Mechanical brake operating lever,
controlled from lever 4 8 Shoe clearance self-adjusting device 9 Wheel cylinders 10 Master cylinder 11 Stoplight
pressure-operated switch
FIG 10:2 Left front wheel brake assembly (500 Sedan)
SHOE
RETURN
SPRINGSHOE MOUNTING
BRACKET SHOE
RETAINING
PLATE SHOES
DEVICESHOE
SELF-ADJUSTING
WHEEL CYLINDERSHOE RETURNSPRING
2 Check that the hydraulic flexible hoses are not con-
taminated with oil or grease which would destroy the
rubber.
3 Ensure that all pipeline fastening clips are secure
otherwise hydraulic line failure could occur due to
cracking caused by excessive vibration.
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4 Carefully clean all connections and inspect for
hydraulic fluid leaks. Should any leaks be detected
then the connections should be tightened taking very
great care not to twist the pipes during this operation.
5 Ensure that the hydraulic fluid level in the reservoir is
correctly filled up to the top of the filter using Fiat
special 'Blue Label' brake fluid. Extra care must be
taken to ensure that no fluid is spilled over the body
paintwork, as this acts as a strong solvent.
6 Ensure that the play between the brake pedal pushrod
and the master cylinder plunger is .019 inch. This will
correspond to approximately .098 inch free pedal
travel.
Never use any fluid but the recommended hydraulic
fluid. Do not leave it in unsealed containers as it will
absorb moisture which can be dangerous. It is best to
discard fluid drained from the system or after a bleeding
operation. Observe absolute cleanliness when working
on all parts of the hydraulic system.
10:3 Front brakes
Front brake drum removal:
1 Remove the wheel trims and carefully slacken the road
wheel retaining bolts. Using a garage hydraulic jack
raise the front of the vehicle and place on firmly
based stands. Remove the road wheels.

2 Using Fiat puller A.46023 as shown in FIG 8 : 9
remove the wheel grease cap.
3 Using a universal t w o leg puller or Fiat puller A.40005
together w i t h items 1 and 9 remove the wheel hub/
drum assembly having first extracted the splitpin if
fitted and released the hub retaining nut (see FIG
8:10).
Dismantling brake unit:
1 Using a compressed air jet thoroughly clean all com-
ponents of the brake assembly.
2 Make a note of the location of the shoe return springs
and gently ease the shoes away from the brake
backplate (see FIG 10:2).
3 Disconnect the hydraulic line from the rear of t h e
wheel cylinder and remove the t w o cylinder retaining
bolts. Lift away the hydraulic cylinder.
Brake shoe lining:
Check the lining thickness and if found to be exces-
sively reduced service replacement shoes must be fitted.
The minimum allowable brake lining thickness is .059
inch.
Thoroughly check the linings for signs of oil or grease
which, if evident, the shoes must be renewed and the
drums and oil seals thoroughly inspected for the cause
of oil ingress and the cause remedied before reassembly.
Do not fit odd brake shoes and do not mix materials or
unbalanced braking will result.
Do not allow grease, oil or paint to contact the friction
linings.
Brake drums:
Whilst servicing the brakes, thoroughly inspect the
drums for scoring, ovality or distortion as well as inspect-
ing for minute hair line cracks. The drums may be refaced
by using a centre lathe and finally finishing by lapping
the drums to smooth out possible tool marks. The
maximum permissible oversize beyond the nominal drum
diameter of 6.702 to 6.712 inch is .039 inch. This limit
must never be exceeded otherwise the strength of the
drum will be impaired or a reduction in braking efficiency
caused by the increase of shoe expansion travel and the
consequent diminished contact pressure.
No brake adjustment will be required on the new 500
Saloon models after the drum has been reassembled as
the self-adjusting device will accommodate for the shoe
position to the new drum diameter during the first
operation of the brake pedal.
Reassembly of front brakes:
This is the reverse procedure to dismantling. Ensure
that the pull-off springs are correctly fitted to the holes in
the webs of the brake shoes and that the shoes register
correctly in the slotted ends of the pistons and the
side
mounting plate.
Upon assembly of the hub and brake drum assembly
liberally pack the space between the two bearings w i t h
Fiat MR grease, and remount the hub according to the
instructions in Chapter 8.
F500
FIG 10:3 Section view of left side f r o n t brake assembly
(500 Station Wagon)
Key to Fig 10:3 1 Wheel cylinder 2 Shoe return spring
3 Adjusting cams 4 Shoe guide pin 5 Shoe with lining
6 Drum 7 Housing flange
BRAKE SHOE
ADJUSTING DEVICE
SHOE WEDGE
SELF
WHEEL CYLINDER
SHOE RETURN SPRING
PARKING BRAKE
SHOE CONTROL
RETURN SPRINGS
LEVER
SHOE LOCK PLATEBRAKE SHOES
SHOE RETURN SPRING
SHOE MOUNTING PLATE
FIG 1 0:4 Right rear wheel brake assembly (500 Sedan)
10:4 Rear brakes
Rear brake drum removal:
1 Remove the wheel trims and carefully slacken the road
wheel retaining bolts. Using a garage hydraulic jack
raise the rear of t h e vehicle and place on firmly based
stands. Remove the road wheels.
2 Remove the four drum to hub retaining bolts and
spring washers and carefully withdraw the drum from
the backplate assembly.
Dismantling brake unit:
1 Using a compressed air jet thoroughly clean all
components of the brake assembly.
105