PREVOST GKN AXLES LIMITED KIRKSTALL DIVISION, Руководство по обслуживанию

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Section 16: SUPPLEMENT INFORMATION ON INDEPENDENT FRONT SUSPENSION (IFS)
16-24
5. AIR SPRING
MAINTENANCE
(FRONT AIR SPRINGS)
Two "rolling lobe" type air springs are used
with the independent front suspension, one at
each wheel. These air springs are special and
use the complete piston as an extra reservoir
to lower the spring stiffness. Front air springs
are attached to the subframe and to uprights.
FIGURE 17: AIR SPRINGS
16052
5.1 Inspection
1. Check operation of bellows.
2. Visually inspect bellows for evidence of
cracks, punctures, deterioration, or chaf-
ing. Replace the bellows if damage is evi-
dent.
3. With the primary air system at normal
operating pressure (95 - 125 psi (655 -
860 kPa)), coat all suspension air line
connections and bellow mounting areas
with a water and soap solution. Bubbles
will indicate an air leak, and none is per-
missible. Repair or replace defective parts.
Note:
If air spring is removed from vehicle,
bellows can be lightly inflated and submerged
in water to detect any leakage. If leakage is
detected, replace bellow.
Warning:
To prevent personal injury, do not
apply more than 10 psi (69 kPa) air pressure
with the air spring unmounted.
5.2 Removal
Note:
Front air springs can be removed with-
out removing the entire suspension assembly.
1. Safely support vehicle at the recom-
mended body jacking points and jack up
body understructure.
2. To gain access to a given air spring, the
corresponding wheel can be removed.
Caution:
Only the recommended jacking
points must be used as outlined in Section 18,
"Body" in the maintenance manual.
3. Support the assembly with a suitable
jack.
See figure 18 for jacking point.
4. Exhaust compressed air from accessory
air tank by opening drain cock under res-
ervoir.
5. Disconnect the height control valve link
and pull down the overtravel lever to en-
sure all air is exhausted from air springs.
Note:
While performing this step, do not
change the height control valve overtravel
lever adjustment.
6. Disconnect air line from air spring, re-
move elbow (if applicable), and cover
both the line end and fitting to prevent the
entry of foreign matter.
7. Remove the two air springs upper nuts,
and then the two lower nuts. Remove air
spring and remove the back up plate from
the top of the air spring.