Chevrolet 70 1969 Series Shop Manual page 891

REMOVAL
1. R em ove clam p yoke an d ad juster plug as previously
outlined.
2. R em ove valve assem bly by grasping stub shaft and
pulling straight out. N O T E : It m ay be necessary to
use pliers to aid in rem oval. Use care not to d a m ag e
stub shaft splines (fig. 9).
DISASSEMBLY
Key num bers in text refer to figure 2.
1. R em ove spool spring (13) by prying on sm all coil with
a sm all screwdriver. D O N O T pry against the valve
body as this m ay result in a sticky valve. W o rk spring
onto bearing d iam eter of stub shaft (20); then slide
spring off shaft.
2. Using ex tre m e caution, rem ove the valve spool (15) as
follows:
The d iam etral clearance between valve and valve spool
(15) m ay be as low as 0.0004 inch. T h e slightest " co ck ­
ing" of spool m ay ja m it in valve body. T o rem ove the
valve spool, hold the valve assem bly in both hands with
stub shaft (20) pointing dow n and tap stub shaft gently
against w ood block. It m a y be necessary to push lightly
on valve spool with a pencil or small brass rod inserted
through openings in valve cap until the spool can be
grasped by hand (fig. 10). W ith d raw spool with a steady
oscillating pull to prevent ja m m in g (fig. 11). If slight
sticking occurs, m a k e a gentle a tte m p t to reverse the
w ithdraw al procedure. If this does not free spool, it has
becom e " c o ck ed " in the valve bod y bore. D o not atte m p t
to force spool in or out of valve body. If such is the case,
continue to disassem ble the valve assem bly as follows and
return to the spool as described later.
3. R em ove the stub shaft, torsion bar, and valve cap as­
sem bly (20) by holding the valve assem bly in both hands
with th u m b s on the valve body. T ap torsion bar lightly
F ig u re 1 0 — L o o se n in g V a lv e Sp o o l
against w o rk bench. This will dislodge the ca p from the
valve body to cap pin. T h e stub shaft, torsion bar, and
valve cap assem bly can then be rem oved fro m the valve
body (18).
4. If the valve spool (15) has becom e " co ck ed " as des­
cribed in step 2 above, it can now be freed. By visual in­
spection on a flat surface, it can be de term in ed in which
direction spool is " co ck ed ." A very few light taps with a
light, soft plastic or raw hide m a llet should align the spool
in bore and free it.
IMPORTANT: Do not tap the spool with any­
thing metallic. If spool can be rotated, it can be
removed.
5. R em ove valve spool d a m p e n e r O -ring seal (14) from
spool and discard.
6. D o not rem ove the control valve (Teflon) rings (16) or
ring back-up seals (17) unless inspection shows nec­
essity. T he valve rings are m ade of T eflon and rarely
require replacem ent.
INSPECTION
1. If valve assem bly leaks a ro u n d torsion bar, the entire
valve assem bly should be replaced.
2. If control valve (Teflon) rings (16) and ba ck -u p seals
(17) show evidence of excessive wear, carefully cut
rings an d seals and remove.
3. C heck the pin in the valve body which engages the
cap. If it is badly worn, cracked, or broken, the entire
valve assem bly should be replaced.
4. C heck the w o rm pin groove in valve body (the sm aller
of the two). If it is w orn badly, the entire valve as­
sem bly should be replaced.
5. C heck spool drive pin in stub shaft (20). If it is worn
badly, replace entire valve assem bly.
6. E xam in e outside d ia m eter of spool (15) for nicks,
burrs, or w ear. If any are found, replace entire valve
assem bly. A slight polish is n o rm a l on the valve su rfa­
ces.
Figure 11— Removing Valve Spool
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SH O P M A N U A L
STEERING 9-15
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