Chevrolet 10 Series 1970 Service Manual page 377

T O O L J - 2 2 9 7 3
F i g . 9 a — T e m p e r a t u r e G a u g e
Inspection
Visual
1. Check fo r p ro p er and secure
pipe and hoses.
2. Check fo r kinked o r d eteriorated hoses. R ep a ir or
rep lace as required.
O p e r a t i o n a l
1. Rem ove a ir clea n er c o v e r and in stall tem perature
gauge (T o o l J-22973) as close as p ossib le to sensor
(fig . 9A).
R ein stall c o v e r without wing nut.
must be below 85°F b efo re p roceed in g.)
2. With the engine " O ff" , ob serve dam per door position
through snorkel opening. Snorkel passage should be
open. If not, check fo r binds in linkage.
3. Start and idle engine. With a ir tem perature below
85°F, snorkel passage should be open. When damper
d oor begins to open snorkel passage,
clea n er c o v e r and o b serve therm om eter reading. It
should be between 85°F and 115°F.
F ig . 10a—C h e c k in g Vacuum Diaphragm
I n s t a l l a t i o n
connections of heat
(T em p eratu re
rem ove a ir
V A C U U M M O TO R REPLACEMENT
DRILL 7 / 6 4 " H O L E
IN C E N T E R P O S I T IO N
O F STR A P
S P O T W E L D S
V A C U U M
D IA P H R A G M
R E T A IN IN G S T R A P
P O S I T IO N
F i g . 1 1 a — V a c u u m
4. If dam per door does not close com pletely o r does
not open at c o r r e c t tem perature, continue with the
follow ing vacuum m otor check:
a. Turn o ff engine. Disconnect diaphragm assem bly
vacuum hose at sensor unit.
b. Apply at lea st 9 in. Hg. of vacuum to diaphragm
assem bly through the hose. This can be done by
mouth. Dam per door
snorkel passage when vacuum is applied. If not
check to see if linkage is hooked up c o rre c tly
and fo r a vacuum leak.
c. With vacuum applied, bend o r clamp hose to trap
vacuum in diaphragm assem bly (fig . 10A).
Dam per door should rem ain in position (closed
snorkel passage).
uum leak in diaphragm assem bly.
phragm assem bly.
5. If vacuum m otor check is found sa tisfa cto ry, replace
sensor unit.
Removal
1. Rem ove a ir clea n er fro m engine.
F ig . 12a— Removing Sensor U n it
ENGINE FUEL 6M -13
IN S T A L L R E P L A C E M E N T
S E N S O R A S S M . IN S A M E
A S O R IG IN A L A S S M .
D i a p h r a g m R e p la c e m e n t
should com pletely close
If it does not, there is a v a c ­
Replace dia­
CHEVROLET TRUCK SERVICE MANUAL