Chevrolet 70 Series 1970, Service Manual

Page: 262 / 841

REAR SUSPENSION 4-49
betw een axle and fra m e such a s th at caused by
ro ad irre g u la ritie s .
The bellows se rv e a s a flexible connection
betw een the fram e and r e a r ax les. Flexing of the
a i r bellow s re s u lts in an a lte rn a te in c re a s e and
d e c re a s e of a ir volum e. T his action ab so rb s road
shocks in the sam e m anner a s an inflated ru b b er
t i r e cushions shock caused by road roughness.
Shock a b so rb e rs a r e double-acting, p isto n -
type. T hese shock a b s o rb e rs control r e a r axle
rebound and fu rth e r cushion rid e. Axle control
a r m s locate r e a r axles again st la te ra l, longitud­
inal, and to rsio n al m ovem ent.
SYSTEM MAINTENANCE
The a ir suspension sy stem re q u ire s little
m aintenance o ther than routine te s t and inspection.
Inspection and te s t p ro c e d u re s should be p e rfo rm ­
ed at established c h a s s is inspection p erio d s. Com­
ponents of suspension a r e shown in fig u re 2.
CAUTIONS
1. Lifting V ehicle
F ro n t of vehicle can be ra is e d in norm al m an­
n er, how ever, when jacking up r e a r ax les position
jack o r hoist so a s not to dam age bellows.
2. Working C learance
B efore working on a i r suspension, support
fra m e a s follows: At r e a r ax les, place a block
betw een axle housings and fra m e to prev en t sudden
Figure 3 —Air Suspension Components
Figure 2 —Air Bellows Components
dropping m otion of fra m e , which could injure
working p erso n n el.
3. Towing
When vehicle is to be towed with r e a r axles
hanging fre e , chain axles to fram e to perv en t axles
fro m hanging by bellow s only.
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL