Chevrolet DB90 Series, Руководство по обслуживанию

Страница: 95 / 242

S ec. 6K-89
EN G IN E C O O LIN G SYSTEM
y» w &
Figure 2 —Tem perature G au g e Sending Unit and
Engine O verheat Switch 112V-71 Diesel EngineI
adequate corrosion p rotection . When coolant addi­
tion s are required b ecau se of coolant lo s s or to
provide additional protection against freezin g at
tem p eratu res low er th a n -2 0 ° F ., (-3 2 °F . inCanada),
a su fficien t amount of an Ethylene G lycol base
coolant m eeting GM Specification 1899-M should
be used .
NOTE: Alcohol or methanol b ase coolants or
plain w ater a re not recom m ended.
IMPORTANT: DO NOT run engine when gauge
or t e ll- ta le indicates "hot" engine.
W ATER TEM PERATURE IN DICATO R
F igu res 2 and 3 illu stra te tem perature gauge
sending units and engine overheat sw itch on 12 V-71
D ie s e l Engine and Cum m ins Six-C ylinder D ie se l
Engine. Information and testin g is d escrib ed on
pages 6K-8 and 6K-9 in S erv ice Manual ST135-70.
EN G IN E THERMOSTATS
Figure 4 illu str a te s the therm ostat installation
of 12V-71 D ie s e l engine on the left sid e of the
engine. T here are four th erm ostats, two in each
sid e. P a g es 6K-9 and 6K-10 in S ervice Manual
ST 135-70 d e sc r ib e s operation and checks.
When replacing th erm ostats make su re and
clean gasket su r fa c e s. In stall gasket, two th erm o­
sta ts, therm ostat housing, and tighten six bolts
se c u r e ly .
V-BELT TENSION
Fan b elt tension on v e h ic le s equipped with
V -b e lts should be adjusted to 120-130 pounds on
Figure 3 —Tem perature G a u g e Sending Unit and
Engine O verheat Sw itch (6 C yl. Cummins Diesel Engine!
new b elts using B T -3 3 -7 3 F B elt T ension Gauge.
U sed d rive V -b e lts should be adjusted to 80-90
pounds. Gauge should be placed at center of the
g r ea test span.
y,
-
IMPORTANT: A fter a b elt has been in o p er­
ation one hour or approxim ately 50 m ile s , it is
con sid ered used. B elt d ressin g can be u sed to e x ­
tend belt life . When V -b elts are worn they should
be replaced a s e x c e s s iv e tightening w ill not p r e ­
vent slippage and can cau se damage to b earin gs.
Figure 4 —Thermostat Installation (12V-71 Diesel Engine)
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT