Facom U.217AS, Operating Instructions Manual

Page: 9 / 44

9
All 4 wheels on the car have the same
potential for vibration and all turn at the
same speed, therefore all need to be
balanced.
With a worn transmission or warped brake
disc/drum causing vibration this cannot
be cured by wheel balancing. For a wheel
with more than 100g imbalance you
should use the optimisation program to
reduce the error. For imbalance over 70g,
after initial balancing it is advised to spin
again for another reading for better
precision.
Advantages of wheel-balancing:
A round well balanced wheel will hold the
road better and brake better with less
wear to the tyres, shock absorbers, track
rod ends, ball joints and steering rack, A
balanced wheel does not vibrate so is more
comfortable for driver and passengers.
3 - Calibration
We advise you recalibrate your U.217AS
every 3 months to retain optimum perfor-
mance.
To calibrate:
- Switch off the U.217AS
- Turn knobs (1), (2) & (3) fully to the right
- Switch on again
- The display will show C-l
- Turn on, spin the shaft (no wheel)
- The display shows C-2; mount in good
condition wheel, min. diameter14". Set
the wheel dimensions (diameter/width/
offset and weight position) then attach
a 50g weight at 12 o’clock on the outer
edge when green indicator light (V)
comes on (follow arrows).
- Spin the wheel
- Display shows C-3/remove the 50g
weight
- Spin the wheel, after the audible beep
the display shows C-F. Calibration is
complete and stored in memory.
Check the calibration
- Balance a wheel exactly (to 0g)
- Attach to each side of the rim a 50g
weight: positioning is not critical.
- Spin the wheel.
- Ensure the wheel balancer indicates
correct (± 5g) imbalance of 50g and that
the position indicated is opposite weight
already attached
- lf not, carry out calibration cycle.
- If an error cannot be corrected, refer to
your dealer.
4- Tests and ajustments/
Servicing
Two modes (7 and S) can be accessed by
the operator. All others to be use only by
Facom service engineer.
To enter test mode, proceed as
follows:
- Switch off the U.217AS.
- Turn knobs (1), (2) & (3) fully to the right .
- Switch on again
- When the display shows the program
version (A-2 for example) turn knob (2)
Fully to the left. When C-1 is displayed
turn the other two knobs fully to the left.
You are now into the test program. This
requires attention and precision timing
as delays between phases are critical).
The test number is obtained using knob
(3) "off-set".
Now proceed as follows:
When in test mode use knob (3) to find
the number of the test required / then
with knob (2) select.
Test7: Selecting grams or ounces
The display indicate the two options:
There are 3 choices of indication on dis-
play (L)
Display in grams
Display in ounces
Test8: Display of values on central pa-
nel
There are 3 types of display available
No display of values
Values displayed - extra fine
Values displayed - normal
To exit test mode, switch off the U.217AS.
5- Error messages
ER1 = Machine stopped before end of cycle
ER2 = Excessive imbalance : ensure centring
and fixing of machine.
ER3 = Excessive imbalance during C-1 (check
if shaft is unloaded)
ER4 = Operation error during C-2 or C-3
(calibration program)
ER6 = Machine running is reverse
199 = Overload: calibrating error.
WHEEL BALANCING ADVISE
Quality of wheels:
After fitting the tyre, inflate to 50 p.s.i
(3.5 bar) to ensure correct bead seating,
then deflate to pressure required by the
manu-facturer. The wheel must not be
eccentric or distorted. With less than
1.5mm of run out and correctly seated,
the wheel is good and can be fitted to
the front axle of the vehicle. More than
4 m m r u n o u t o r i n c o r r e c t s e a t i n g ,
change the wheel or tyre. Clean rim and
r e m o v e s t o n e s f r o m t h e t y r e t r e a d ,
Remove old weights before refitting.
Centring the wheel on the flange:
Use mounting accessories of exactly the
correct type for the wheel and method
of fixing to the vehicle (see accessories
g u i d e s u p p l i e d w i t h t h e U 2 1 7 A S ) .
Mount the wheel on the flange, ensuring
the valve is on top.
Turn the wheel by hand whilst tightening
nuts or centre nut.
Secu re tightly.
Mounting wheel on vehicle:
Clean the bearing surface of the wheel
on the vehicle hub.
Remount wheel with valve at top.
Tighten wheel nuts to manufacturer’s
recommended torque, starting at the top
(with wheels off ground: never use an im-
pact wrench). A wheel out of true by 0.1
mm causes an imbalance of c10g.
Remarks:
An out of true/distorted wheel, even if
well balanced, will always cause vibration.
It is not possible to correct millimeters with
grams: grams correct grams, millimeters
correct millimeters.
Modern MacPherson type suspensions are
more sensitive to imbalance than older types.