Chevrolet DB90 Series, Руководство по обслуживанию

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S ec. 8B-175
SECTION 8B
fjt d i& u A t S if it e m
A ll inform ation in Section 8B of the 1970 Heavy Duty Truck S erv ice Manual
S T 135-70, startin g on page 8 -9 is applicable to m odels covered by this supplem ent.
The follow ing inform ation has been added:
Figure 1—Exhaust Pipe Clam p Installation
EXHAUST SYSTEM ALIGNMENT
During in stallation of a new exhaust pipe,
m uffler or ta il pipe, care should be taken to prop­
erly position com ponents in relation to each other.
P articu lar care should be given to the installation
of the exhaust pipe and c ro sso v e r pipe assem b ly
on "V" engines equipped with sin g le exhaust sy stem .
On a ll joints except exhaust manifold, apply
s e a le r (GM 9985020) or equivalent, to prevent
p o ssib le le a k s.
In correctly a ssem b led p a rts of exhaust s y s ­
tem are frequently the ca u se of annoying n o ises
and ra ttles due to im proper cle a r a n c e s. T h erefore,
lea v e a ll clamp U -b olts and m uffler strap b olts
lo o se tem p orarily until the entire sy ste m has been
in sp ected to determ ine if there is adequate c le a r ­
ance between exhaust com ponents and fram e m em ­
b e r s . The weight of the exhaust sy ste m should be
properly distributed on a ll supporting b rack ets and
hangers. If the load is not properly balanced, r e ­
p osition p ipes at connecting joints to r e lie v e any
concentrated load s. A fter adjusting hangers, align­
ing p ip es, and repositioning m uffler, check entire
sy ste m for adequate clea ra n ce and then tighten a ll
clam p s, working from front to rea r. Start engine
and inspect a ll connections for leakage.
NOTE: When in stallin g exhaust pipe to m ani­
fold, alw ays u se new packing and nuts. B e sure to
clean m anifold stud threads with a w ire brush b e­
fo r e in stallin g new nuts.
The exhaust pipe clam ps m ust be in stalled
o v er s lo ts in exhaust pip es as shown in figure 1.
NOTE
Exhaust sy ste m perform ance com plaints such a s e x c e s s iv e back p r e ssu r e or
a m alfunctioning gasolin e engine exhaust control valve a re usually noticeable by
th eir effect on engine perform ance.
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CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT