Chevrolet 70 1969 Series, Shop Manual

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CAB A N D BO DY M O U N T IN G S 1-2
Figure ? — Installing Insert-Retained Glass
inside cab may actually be entering at a point other
than where water is found. Back-track path of
water to point of entry.
After location of leak has been determined
around glass, dry surface and apply rubber cement.
Apply cement to outside, both between glass and
weatherstrip and between weatherstrip and body.
Apply body sealing compound over all the
other leak points.
If leakage occurs at door opening, check w ea­
therstrip. Replace if necessary. If door does not
firmly contact weatherstrip, align door as des­
cribed in applicable cab section.
CAB ALIGNMENT
Since cab is an integrally welded structure,
repair should be attempted only by competent
craftsman using proper tools and equipment. For
best results, only genuine factory parts should be
used for replacement. As work progresses, cross­
checking with an adjustable tram bar is recom­
mended for obtaining proper alignment.
STRAIGHTENING
Before attempting repair of a damaged cab,
the chassis frame must be checked and aligned as
described in F R A M E (SEC. 2).
To straighten frame, it may be necessary to
remove cab. Never attempt to straighten cab unless
cab is firmly attached to chassis. The inner panel­
ing of cab should be straightened first. Use of a
push-pull hydraulic jack, together with extension
and adapters is recommended for this type of repair.
After straightening framing, it is important
that strains set up in framing be relieved or "nor­
malized." Normalizing consists of heating areas
of greatest tension with a torch. Holding torch
nozzle about 2 " from metal, move torch over an
area of 3" to 4 " until the metal barely begins to
turn red. Cooling must be slow to avoid changing
characteristics of the metal. Apply slight heat with
torch, if necessary, to retard cooling.
DING ING AND FINISHING
Paint is quickly scuffed off sharp dents leaving
metal exposed to rusting and corrosion; therefore,
importance of proper metal finishing to produce a
fairly smooth surface should not be underestimat­
ed. Application of hammer directly to panel tends
to stretch the metal and cause a great deal of un­
necessary work. Whenever possible, a spoon should
be used under the hammer when bumping a panel.
Repair damaged panels by forcing outward in direc -
tion opposite to force which caused damage. In this
way metal strains, set up when damage occurred,
are relieved.
PAINTING
REPAIN TING
1. Thorough cleaning is essential. All corro­
sion products, grease, and other foreign matter
must be removed. Use of phosphoric base metal
conditioners, such as "Metalprep" (Neilson Chem ­
ical Co.) or "Dioxidine” (American Chemical Paint
Co.) or equivalent is recommended in preparing
steel for painting. These materials vary in method
of application and use, and should be employed only
as directed by the manufacturer. Solvent cleaning,
pressure steam cleaning, wire brushing, and hand
sanding methods are recommended.
2. Completely remove old paint by use of
organic or alkaline solvents. However, if alkaline
removers are used, all traces of alkali must be
washed off before primer is applied. If old primer
is very difficult to remove, and if there is no evi­
dence of metal corrosion, old primer may be left
on, but all loose paint must be removed.
3. Apply primer, preferably by spraying, and
allow to dry. Use a good oxide primer obtained
from a reputable manufacturer.
4. Apply finish coats:
a.
For understructure or other parts not re­
quiring color, apply two coats of a good air-drying
black or other automotive lacquer.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L