Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Руководство по обслуживанию

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ENG IN E CO O LING 6K-2
W ater pum p co m p o n en ts are n o t serviced separately; th e re ­
fore, in th e event o f w ater p u m p failure, it will be necessary to
replace th e com plete assem bly — rem oval an d in stallation
Coolant Level
The rad iato r co o lan t level should only be checked w hen the
engine is cool, particu larly on trucks equipped w ith air
conditioning. I f th e rad ia to r cap is rem oved from a h o t cooling
system , serious personal injury m ay result.
The cooling system flu id level in dow nflow rad iato r should
be m aintained one inch b elo w th e b o tto m o f th e filler neck o f
th e rad ia to r w hen cooling system is cold. C oolant level in
crossflow radiators should be m aintained three inches below
th e b o tto m o f the filler n ec k w hen the system is cold to allow
for expansion w hen th e coolant is heated . (N ote coolant level
arrow on rear o f rad ia to r o u tle t ta n k .) It is very im p o rta n t th a t
th e correct fluid level b e m aintained. Overfilling will result in
loss o f coolant as th e co o la n t expands while underfilling (low
level) will result in reduced cooling perform ance.
All tru c k cooling system s are pressurized w ith a 15 lb.
pressure cap w hich perm its safe engine o p eratio n a t cooling
tem peratures o f u p to 256° F. w ith a 33% glycol solution.
When th e rad ia to r cap is rem oved or loosened, the system
pressure drops to atm ospheric, a n d th e h ea t w hich h ad caused
w ater te m p eratu re to b e higher th a n 2 1 2 °F , will be dissipated
b y conversion o f w ater to steam . Inasm uch as th e steam m ay
fo rm in th e engine w ater passages, it will blow co o lan t o u t o f
th e rad ia to r u p p er hose a n d to p ta n k , necessitating coolant
replacem ent. Engine o perating tem p eratu res higher th a n the
norm al boiling p o in t o f w ater are in no w ay objectionable so
long as th e coolant level is satisfactory w hen th e engine is cool.
U pon rep eated co o lan t loss, th e pressure rad iato r cap and
seat should be checked for sealing ability. Also, th e cooling
system should be checked for loose hose connections, defec­
tive hoses, gasket leaks, etc.
procedures are covered in this section. F or rad ia to r service
refer to S ection 13 o f this m anual. R adiator fan shroud
replacem ent is covered in S ection 11 o f this m anual.
ADJUSTMENTS
3. To check for exhaust leaks in to th e cooling system , drain
the system u n til the w ater level stands ju st above the top
o f th e cylinder head, th e n disconnect th e u pper radiator
hose an d rem ove th e th e rm o sta t and fan belt. S tart th e
engine and quickly accelerate several tim es. A t th e same
tim e n o te any appreciable w ater rise or th e appearance o f
bubbles w hich are indicative o f exhaust gases leaking in to
th e cooling system .
Periodic Maintenance
It is th e ow ner’s responsibility to keep the freeze p ro tectio n
at a level com m ensurate w ith the area in w hich th e vehicle will
be o perated. Regardless o f clim ate, system p ro tec tio n should
be m aintained a t least to
0
° F ., to provide adequate corrosion
p ro tec tio n . When adding solution due to loss o f co o lan t for
any reason or in areas w here tem peratures low er th a n -20° F.
m ay occur, a sufficient am o u n t o f an ethylene glycol base
coolant th a t m eets GM Specification 1899-M should be used.
Every tw o years th e cooling system should be serviced by
flushing w ith plain w ater, th e n com pletely refilled w ith a fresh
solution o f w ater and high-quality inhib ited (perm anent-type)
glycol base coolant m eeting GM Specification 1899-M, and
providing freezing p ro tec tio n at least to 0 °F . A t this tim e, also
add GM Cooling System In h ib ito r an d Sealer or equivalent. In
additio n , Cooling System In h ib ito r and Sealer should be added
every fall th e re afte r. GM Cooling System In h ib ito r retards th e
fo rm atio n o f rust o r scale and is com patible w ith alum inum
com ponents.
N O T E : Alcohol or methanol base coolants or plain
water are n ot recommended fo r your cooling system
at any tim e.
MAINTENANCE AND
Coolant System Checks
1. T est for restrictio n in th e radiator, by w arm ing th e
engine up and th e n turning th e engine o ff and feeling th e
rad iato r. The rad ia to r should be h o t at th e to p (along the
left side o n crossflow rad iato rs) and w arm at th e b o tto m
(along the right side o n crossflow radiators), w ith an even
te m p eratu re rise from b o tto m to to p (right to left on
crossflow radiators). C old spots in th e rad iato r indicate
clogged sections.
2. W ater pum p o p era tio n m ay be checked b y running the
engine w hile squeezing th e upper radiator hose. A
pressure surge should be felt. C heck for a plugged
vent-hole in pum p.
N O T E : A defective head gasket may allow exhaust
gases to leak into the cooling system. This is
particularly damaging to th e cooling system as the
gases combine w ith the water to fo rm acids which
are harm ful to both the radiator and engine.
Two com m on causes o f corrosion are: (1) air suctio n —
Air m ay be draw n into th e system due to low liquid level in
the rad iato r, leaky w ater pum p o r loose hose co nnections; (
2
)
exhaust gas leakage — Exhaust gas may be blow n into the
cooling system past th e cylinder head gasket or th rough cracks
in th e cylinder head and block.
Cleaning
A good cleaning solution should be used to loosen th e rust
and scale before reverse flushing th e cooling system . T here are
a nu m b er o f cleaning solutions available an d th e m anufac­
tu re r’s in stru ctio n s w ith th e particular cleaner being used
should always be follow ed.
A n excellent prep aratio n to use fo r th is purpose is GM
C ooling System Cleaner or its equivalent. The follow ing
directions for cleaning th e system applies only w hen this type
cleaner is used.
1. D rain, the cooling system including th e cylinder block,
and th e n close drain plugs.
2. Rem ove th e rm o stat an d replace th e rm o stat housing.
C H E V Y V A N SHO P M A N U A L