Jeep Cherokee 1999 Electronic Service Manual page 1286

X J
DESCRIPTION AND OPERATION
POWER STEERING PUMP . . . . . . . . . . . . . . . . . 5
DIAGNOSIS AND TESTING
POWER FLOW AND PRESSURE . . . . . . . . . . . . . 5
PUMP LEAKAGE DIAGNOSIS . . . . . . . . . . . . . . . 6
SERVICE PROCEDURES
POWER STEERING PUMP – INITIAL
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
REMOVAL AND INSTALLATION
POWER STEERING PUMP . . . . . . . . . . . . . . . . . 7
DESCRI PT I ON AN D OPERAT I ON
POWER STEERING PUMP
H ydr a u lic pr essu r e is pr ovided for oper a t ion of t h e
power st eer in g gea r by a belt dr iven power st eer in g
pu m p. Th e power st eer in g pu m p is a con st a n t flow
r a t e a n d displa cem en t , va n e-t ype pu m p. Th e in t er n a l
pa r t s in t h e h ou sin g oper a t e su bm er ged in flu id. Th e
flow con t r ol or ifice is pa r t of t h e h igh pr essu r e lin e
fit t in g. Th e pr essu r e r elief va lve in side t h e flow con -
t r ol va lve lim it s t h e pu m p pr essu r e. Th e r eser voir is
a t t a ch ed t o t h e pu m p body wit h spr in g clips on t h e
4.0L en gin e. On t h e 2.5L en gin e t h e r eser voir is sep-
a r a t e fr om t h e pu m p.
Th e power st eer in g pu m p is con n ect ed t o t h e st eer-
in g gea r by t h e pr essu r e a n d r et u r n h oses. Th e pu m p
sh a ft h a s a pr essed-on dr ive pu lley t h a t is belt dr iven
by t h e cr a n ksh a ft pu lley (F ig. 1).
NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.
DI AGN OSI S AN D T EST I N G
POWER FLOW AND PRESSURE
Th e followin g pr ocedu r e is u sed t o t est t h e oper a t ion
of t h e power st eer in g syst em on t h e veh icle. Th is t est
will pr ovide t h e ga llon s per m in u t e (GP M) or flow r a t e
of t h e power st eer in g pu m p a lon g wit h t h e m a xim u m
r elief pr essu r e. P er for m t est a n y t im e a power st eer in g
syst em pr oblem is pr esen t . Th is t est will det er m in e if
t h e power st eer in g pu m p or power st eer in g gea r is n ot
fu n ct ion in g pr oper ly. Th e followin g pr essu r e a n d flow
t est is per for m ed u sin g P ower St eer in g An a lyzer Tool
Kit 6815 (F ig. 2) a n d Ada pt er Kit 6893.
POWER ST EERI N G PU M P
INDEX
page
PUMP RESERVOIR-2.5L . . . . . . . . . . . . . . . . . . . 8
DISASSEMBLY AND ASSEMBLY
PUMP PULLEY . . . . . . . . . . . . . . . . . . . . . . . . . . 8
PUMP RESERVOIR . . . . . . . . . . . . . . . . . . . . . . . 9
FLOW CONTROL VALVE . . . . . . . . . . . . . . . . . . . 9
SPECIFICATIONS
TORQUE CHART . . . . . . . . . . . . . . . . . . . . . . . . 10
SPECIAL TOOLS
POWER STEERING PUMP . . . . . . . . . . . . . . . . . 10
Fig. 1 Pump With Integral Reservoir
FLOW AND PRESSURE TEST
(1) Ch eck t h e power st eer in g belt t o en su r e it is in
good con dit ion a n d a dju st ed pr oper ly.
(2) Con n ect pr essu r e ga u ge h ose fr om t h e P ower
St eer in g An a lyzer t o Tu be 6865.
(3) Con n ect Ada pt er 6826 t o P ower St eer in g An a -
lyzer t est va lve en d.
(4) Discon n ect h igh pr essu r e h ose a t gea r or pu m p.
Use a con t a in er for dr ippin g flu id.
(5) Con n ect Tu be 6865 t o t h e pu m p h ose fit t in g.
(6) Con n ect t h e power st eer in g h ose fr om t h e
st eer in g gea r t o Ada pt er 6826.
STEERING 19 - 5
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