Chevrolet Light - Springsandshackles

namely, th e control valve assembly, the vacuum pow er cylinder
and the brake hydraulic cylinder.
With this system
the engine vacuum is used to grea tly in-
crease the hydraulic pressure to the brake wheel cylinders.
This provides
unusual brakin g efficiency with comparatively
li
ght pedal pr essure.
Care . This unit does not ha ve any externa l moving parts or
linkage a nd is prope rly sealed against dust and water; there-
fore, it will give unusual service with ve ry little care or
maintenance. L ubrica te the va cuum cy linder according to in-
structio ns in the Lub ri cat ion Se ction.
The vacuum connections betw een the engine and th e hy-
drovac should be checked for damage and the connections
tightened occasionally.
The hydrovac air cleaner shou ld be re-
moved, disassembled, cleaned and oil ed at l east twice a year
a nd mo re frequently w hen driving on dusty roads.
SPRINGS AND SHACKLES
Front Springs and Shackles
Description. All Chevrolet t rucks use l ea f type front springs.
The 1,.2 and %. ton use an 8-leaf spring 38" long and 1 %" wide.
The % and 1 ton Forward Contr ol units are equipped with 8
leaf
spr ings, 40" long an d 2" wide. All other models u se 40"
springs, 2" wide with from 7 to 11 leaves. All models except the
Cab-Over -Engine and Forward Control have a threaded bush-
ing and pin type .shackle ;1t the front and a plain bushing and
bolt at the rear hanger. The C.O.E. and Forward Control models
h
ave the shac kl e at the rear and the fixed han ger at the front.
Care.
The sp ring to "1" beam U-OOlts should be checked oc-
casionally to make sure they are tight. Th e shackl es and
hanger bolts shou ld be checked fo r proper tightness. The
shackles and hanger bushings shou ld be lubricated as in-
structe d in the Lubrication Section.
Rear Springs and Shackles
De scr iption. All models h ave leaf type rear springs with the
shackle at the rear end of spring; however, the length, wi dth
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