1971 FIAT 500 Point gap

high bearing preload. To reset remove the wheel shaft
and fit a new resilient spacer. Repeat the rotation
torque test.
Swinging arm adjustment:
To adjust the swinging arm use Fiat fixture A.66064 as
shown in FIG 7 : 3 and proceed as follows:
1 At points A and B as indicated in FIG 7 : 4 between the
'estendblock' and the swinging arm to body front
mounting bracket fit three shims on each side. To
ensure that the shims are correctly centred use Fiat
alignment bar A.66057.
2 Whilst removing the alignment bar, carefully slip in the
mounting pin and screw on the nut. Once the rear
wheel geometry adjustment has been completed this
nut should be tightened to a torque wrench setting
of 43.4 to 50.6 Ib ft.
3 At points C and D (see FIG 7 : 4) , insert the number of
shims required to fill in the gap between the 'estend-
block' and the two fixture shoulders. Having deter-
mined the number of shims required both at locations
C and D, these must later be fitted between the
'estendblock' and the shoulders on the swinging arm
to body mounting bracket.
7 : 4 Coil springs
The coil springs should be thoroughly cleaned and all
traces of rust removed. Inspect the spring coils for hair
line cracks, which if evident, a new pair of springs must
be fitted to ensure correct vehicle height and stability.
Check the free
height and the height under loading of
the coil springs and these must correspond to the figures
quoted in Technical Data.
7:5 Installation of rear suspension assembly
To replace the rear suspension assembly proceed as
follows:
1 Insert the swinging arm inner end in the mounting
bracket which is welded onto the body floor. Place
between the 'estendblock' and bracket the number of
adjustment shims as previously determined using Fiat
fixture A.66064 as shown in FIG 7 : 4. Insert the Fiat
alignment bar A.66057 through 'estendblock' and
shims, aligning them with the holes in the mounting
bracket. Firmly hold the entire assembly using a garage
hydraulic jack if necessary, and carefully remove the
alignment bar and at the same time ease in t h e
mounting pin. Secure the nut which once the rear
wheels geometry has been checked must be tightened
to a torque wrench setting of 43.4 to 50.6 Ib/ft.
2 Screw in finger tight the three swinging arm external
bracket to body floor mounting screws together w i t h
the plain and spring washers. The screws will have to
be tightened to a torque wrench setting of 28.9 to
36.2 Ib/ft once the rear wheel geometry has been
adjusted.
3 Carefully insert the coil spring, lower insulator ring
onto the swinging arm, insert the spring on the shock
absorber which should be previously secured to the
arm and position the spring onto its seat on the arm.
Place the upper insulator ring onto the spring, raise the
suspension assembly using a garage hydraulic jack and
insert the spring onto its seating under the body floor.
F50083 4 Ensure that the shock absorber to floor rubber ring has
been correctly fitted and extend the shock absorber
until its upper mounting pin protrudes into the vehicle
through the hump in the floor panel. Secure the shock
absorber by its mounting nut and lockwasher having
first inserted the rubber ring and plain washer.
5 Refit the rear wheel housing in place, reconnect the
brake line to the connection on body floor and remove
the plug from the output hole in the brake fluid
reservoir. Bleed the hydraulic brake system as
described in Chapter 10.
Key to Fig 7:8 k Distance of centre rear bracket, for
jacking up the vehicle, from floor level (8.90 inch)
Half-track = 22.264 inch ±.059 inch
FIG 7 : 8 Position of rear suspension f o r rear wheel
toe-in inspection and adjustment ('500 Station Wagon') FIG 7 : 7 Adjusting rear wheel toe-in angle
Key to Fig 7 : 7 Rear wheel plane must be perpendicular to
ground and parallel to car longitudinal centerline with a
tolerance of 0° 10'
To adjust rear wheel geometry, move suitably the swinging arm
outer support. Slight movements are permitted by the play
existing between the support holes A and the mounting screws.
Screws B must be tightened to 28.9 to 36.2 Ibft (4000 to 5000
kg mm). Nuts C must be tightened to 43.4 to 50.6 Ib ft (6000
to 7000 kgmm), after adjustment has been carried out. (These
directions and specifications are also applicable to 500 Station
Wagon).

normal straight-ahead position with the spokes
horizontal. Check that the wheels are in the straight-
ahead position.
2 Load the vehicle to static load conditions or with four
average size passengers.
3 Move the vehicle forwards for a distance of approxi-
mately six yards so that the suspension may settle
correctly.
4 The toe-in measurements should be taken at the same
point of the wheel rim. Measure at A (see FIG 9 : 8)
then back up the car to bring points A to the position B
and remeasure. The value obtained at A should be
equal to or greater than B within .0079 inch.
5 As previously described the steering rods are adjust-
able in length. Loosen the clamps and screw in or out
the adjusting sleeves and before tightening the clamp
ensure that the sleeve slot registers w i t h the clamp
joint. With the clamp fully tightened there should
always be a gap between the joint faces.
6 If the steering gear has been re-installed the correct
front wheel toe-in must be set. Then the relay lever pin
nut must be tightened to a torque wrench setting of 78
to 85 Ib/ft.
9 : 8 Fault diagnosis
(a) Front wheel shimmy
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Loose front wheel bearings
4 Wheels out of balance
5 Loose steering linkage connections
6 Loose steering gear or relay lever support at body
mountings
7 Incorrect fitting of steering worm to worm sector
(b) Hard steering
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Incorrect adjustment of steering worm to worm sector
(c) Hard turning when stationary
1 Incorrect tyre pressure
2 Incorrect adjustment of steering worm to worm sector
102
(d) Pull to one side
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Incorrect front wheel bearing adjustment
4 Distorted kingpin housing or swinging arms
5 Unequal brake adjustment
6 Semi-elliptic spring weak or broken
(e) Rattles
1 Loose steering linkage connections
2 Loose steering gear or relay lever support at body
mountings
3 Semi-elliptic spring weak or broken
4 Lack of lubrication
( f ) Loose steering
1 Incorrect front wheel bearing adjustment
2 Loose steering linkage connections
3 Loose steering gear mountings
4 Incorrect adjustment of steering worm to worm sector
(g) Jerky steering
1 Incorrect front wheel alignment
2 Incorrect front wheel bearing adjustment
3 Wheels out of balance
4 Loose steering linkage connections
5 Loose or incorrect fitting of worm to sector
(h) Side-to-side wander
1 Incorrect tyre pressure
2 Incorrect front wheel alignment
3 Loose steering linkage connections
4 Loose steering gear or relay lever support at body
mountings
5 Incorrect fitting of steering worm to worm sector
6 Distorted kingpin housing or swinging arm
7 Semi-elliptic spring weak or broken
(i) Tyre squeal on turns
1 Incorrect tyre pressure
2 Incorrect wheel alignment
3 Distorted kingpin housing or swinging arms

FIG 10:5 Section view of right side rear brake assembly
(500 Station Wagon)
FIG 10:6 Sectional view of a self-adjusting device for
automatic brake shoe-to-drum clearance take-up (500
Sedan)
Key to Fig 1 0 : 6 1 Pin 2 Friction washers 3 Load spring
4 Bushing 5 Shoe 6 Self-adjustment slot 7 Stud
2 Make a note of the location of the shoe return springs
and gently ease t h e shoes away from the backplate
(see FIG 10:4)
3 Disconnect the hydraulic line from the rear of t h e
wheel cylinder and also the shoe operating lever return
spring, the pin, washer and clevis from the lever so
releasing the handbrake inner operating cable.
4 Remove the t w o cylinder retaining bolts and lift away
the hydraulic cylinder.
106
Brake shoe linings:
Refer t o Section 10:3.
Brake drums:
Refer to Section 10:3.
Reassembly of rear 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 in the slotted ends of the pistons and the side
mounting plate.
Carefully retract the position of the brake shoes and
ease t h e d r u m towards the hub ensuring that the four
bolt holes line up correctly. Replace the four bolts
together with their spring washers, reconnect the hand
brake cable. Refit road wheel and wheel trim.
10:5 Master cylinder
Operation:
Hydraulic fluid is admitted to the master cylinder
through hole 8 (see FIG 10:7), it seeps through the gap
between the valve carrier ring 17 and the master cylinder
dowel and flows through the valve carrier ring holes 15
so reaching the hydraulic lines, therefore filling the
system w i t h fluid. When the brake pedal is depressed the
plunger is moved forwards by the pushrod 12. This
forward action of the plunger 9 and valve carrier 17 brings
the valve 16 to rest against the valve front face. The
forward movement is continued so causing the valve ring
16 to pass over the compensation hole 5 and cutting off
communication with the fluid reservoirs. From this point
compression of the hydraulic fluid commences.
Hydraulic fluid acting on the front and inner faces of
the valve enables perfect valve sealing even under high
operation pressures. When the pressure reaches the fluid
in the wheel cylinders (see FIG 10:8) , it forces the
plungers 3 apart and through the plungers stems so
operating the brake shoes.
After releasing the brake pedal, the combined action
of the brake shoe and master cylinder plunger return
springs sends the fluid back to the master cylinder and
all parts resume their original position. The connection
between the hydraulic
system and the reservoir is
restored.
As there are no conventional valves fitted in the master
cylinder and the communication orifice between the
system a n d the reservoir is amply dimensioned the
bleeding operation is very straightforward.
Master cylinder removal:
1 Disconnect the stoplight cables from the pressure
operated switch.
2 Using a tapered w o o d plug of suitable size blank t h e
hole in the brake f l u i d reservoir.
3 Screw out the four front and rear cylinder brake fluid
delivery line connections at the master cylinder.
4 Remove the t w o master cylinder retaining nuts and
spring washers and carefully ease the hydraulic
cylinder from the body.