Chevrolet 1977 light duty truck Service Manual page 224

pump. It is easier if someone else operates the steering
wheel while you search for the seepage.
D. Find the exact area of leakage.
E. Refer to the diagnostic
recom m ended method of repair.
Quick Fixes
The purpose o f this section is to acquaint you with
the types o f leakage which can be repaired very easily. It
contains inform ation on reservoir oil level, the hoses and
the hose connections.
An overfilled pu m p reservoir can be a cause for
leakage complaint. The
expands as heated during norm al usage. If overfilled the
excess is forced thhrough the b reath er cap hole and may
be sprayed over the engine by air blast. O perate the
engine and steering system
tem perature is obtained. Remove the reservoir cap and
check the graduated level on the dipstick. Adjust the oil
level as required.
Seepage at the hose connections can be a cause for
leakage com plaint and can be due to loose connection
nuts. If leakage is observed at the hose connections, and
the nut is not cross threaded, tighten the nuts at the gear
to 30 foot pounds.
The nut at the power steering pu m p should be
tightened to 40 foot pounds. If tightening to this torque
does not stop the leak, refer to the diagnostic chart.
If either the return hose or the pressure hose leaks,
replace the hose.
Component Replacement
Lip seals, which seal rotating shafts, require special
treatm ent. This type of seal is used on the steering gear
at the p itm a n shaft, at the stud shaft, and on the drive
shaft o f the pump. W hen leakage occurs in one o f these
areas, always replace the seal(s), after inspecting and
thoroughly cleaning the sealing surfaces. Replace the
shaft only if very severe pitting is found. If the corrosion
in the lip seal contact zone is slight, clean the surface of
the shaft with crocus cloth. Replace the shaft only if the
leakage can no t be stopped by smoothing with crocus
cloth first.
chart to find the
oil in the steering system
until normal operating
Housing or Cover Seepage - Both the power steering
gear and pu m p assemblies are leakage checked before
shipment. However, occasionally oil seepage m ay occur
from the gear or pum p other than the seal areas. If this
type of leakage is found, replace the leaking part.
The following diagram s have been prepared to show
the potential areas o f leakage. If leakage occurs in the
zones shown, replace the part listed using the service
manual as a guide.
Steering Gear Leakage Diagrams (Fig. 3B -27)
Pay particular attention to the exact source of
leakage as an im proper diagnosis will result in an
ineffective repair.
1. Replace adjuster plug " O " R IN G SEAL.
2. Replace dust and stub shaft seals. Refer to
above on stub shaft seal ride.
3. Replace rotary valve assembly.
4. Seat ball flush with punch and
seepage persists, replace housing.
5. Replace both pitman shaft seals. Refer to above
on seal ride area o f p itm an shaft.
6. Replace end plug " O " ring seal.
7. Tighten nut to 35 pounds foot. Replace nut if
leakage persists.
8. Replace side cover "O " ring seal.
9. If leakage persists upon tightening the fitting
nut (30 foot pounds), replace brass connector and reface
hose tube flare. If leakage is due to d am aged threads
(cross threaded), replace brass connector. Repair fitting
nut or replace hose as required. If housing threads are
badly stripped, replace housing.
Pump Leakage Diagrams (Fig. 3 B -28)
10. Tighten hose fitting nut to 40 pounds foot. If
leakage persists, replace discharge fitting and reface hose
tube flare or replace hose as required.
11. Tighten fitting to 35 pounds foot. If leakage
persists, replace both " O " ring seals.
12. Replace reservoir " O " ring.
13. Replace drive shaft seal. Refer to above on
seal ride area of drive shaft.
14. Replace reservoir.
15. Check oil level. If leakage persists with the
level right and the cap tight, replace the cap.
restake. If