Chevrolet 70 1969 Series, Shop Manual

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STEERING SYSTEM 9B-36
CONTROL VALVE A N D POWER STEERING GEAR (Cont.)
C O N D I T I O N
C A U S E R E M E D Y
Hard steering when
parking. (Cont'd)
C om p aring the m axim um p ressu res ob tained in these tw o tests
w ill in d icate source of tro ub le as fo llo w s:
( a ) First test p ressure low and second test p ressu re n o r m a l-
in d icates fa u lty external oil lines, or steerin g gear.
(h ) First test and second test p ressures eq u a lly lo w — in d icates
fau lty oil pum p.
If the above test show s tro ub le to be in pum p, see h y d ra u lic
pum p pro ced ures d escrib ed p revio usly.
If trouble is show n to be in steering gear or hoses, ex a m in e for
external oil leaks as d escrib ed under L E A K S — IT E M 5.
Low oil pressure due to restriction in hoses:
a. C heck for kinks in hoses.
b. Foreign ob ject stuck in hose
Low oil p ressure due to steering gear
Rem ove kinks.
R em ove hoses and rem ove restricting ob ject or rep lace hose.
a. Leakage at va lve rings, valve body to w orm
seal.
b. Loose fit of spool in va lve hody or leaky valve
body.
Rem ove gear from truck for d isassem b ly and rep lace seals.
R ep lace valve.
13. No effort required
to turn.
B ro ke n torsion bar
R ep lace torsion bar and stub shaft assem b ly.
POWER CYLINDER
1. Internal leaks. M o m en ta ry in creased effort w hen turn ing w heel. R eplace cy lin d er assem bly.
2. External leaks. A ro und piston rod seals.
A t hose connections.
A round w eld ed joints.
1. R ep lace seals.
2. C y lin d e r relief va lve not w o rk in g — rep lace c y lin d er a ssem b ly.
Tighten or rep lace cylin d er if tightening does not rem ed y cond ition.
Replace cylin d er assem b ly.
3. E x cessive ball
socket movement.
End play present.
W orn ball seats.
A d ju st to specifications.
R ep lace seats.
4. Piston rod end
clamp movement.
Loose bolts.
Torque to sp ecifications a fte r pro p er p ositioning to sp ecifications.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHOP MANUAL