Jeep Cherokee 1999 Electronic Service Manual page 1063

9 - 46 2.5L ENGINE
REM OVAL AN D I N STALLAT I ON (Cont inue d)
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR FAN. DO
NOT WEAR LOOSE CLOTHING.
(19) St a r t t h e en gin e a n d in spect for lea ks.
OIL PUMP
Th e posit ive-displa cem en t gea r-t ype oil pu m p is
dr iven by t h e dist r ibu t or sh a ft , wh ich is dr iven by a
gea r on t h e ca m sh a ft . Oil is siph on ed in t o t h e pu m p
t h r ou gh a n in let t u be a n d st r a in er a ssem bly t h a t is
pr essed in t o t h e pu m p body.
Th e pu m p in cor por a t es a n on a dju st a ble pr essu r e
r elief va lve t o lim it m a xim u m pr essu r e t o 517 kP a
(75 psi). In t h e r elief posit ion , t h e va lve per m it s oil t o
bypa ss t h r ou gh a pa ssa ge in t h e pu m p body t o t h e
in let side of t h e pu m p.
Oil pu m p r em ova l or r epla cem en t will n ot a ffect
t h e dist r ibu t or t im in g beca u se t h e dist r ibu t or dr ive
gea r r em a in s in m esh wit h t h e ca m sh a ft gea r.
REMOVAL
(1) Dr a in t h e en gin e oil.
(2) Rem ove t h e oil pa n .
(3) Rem ove t h e pu m p-t o-cylin der block a t t a ch in g
bolt s. Rem ove t h e pu m p a ssem bly wit h ga sket (F ig.
62).
CAUTION: If the oil pump is not to be serviced, DO
NOT disturb position of oil inlet tube and strainer
assembly in pump body. If the tube is moved within
the pump body, a replacement tube and strainer
assembly must be installed to assure an airtight
seal.
INSTALLA TION
(1) In st a ll t h e oil pu m p on t h e cylin der block u sin g
a r epla cem en t ga sket . Tigh t en t h e bolt s t o 23 N·m
(17 ft . lbs.) t or qu e.
(2) In st a ll t h e oil pa n a n d ga sket .
(3) F ill t h e oil pa n wit h oil t o t h e specified level.
PISTONS AND CONNECTING RODS
REMOVAL
(1) Rem ove t h e en gin e cylin der h ea d cover.
(2) Rem ove t h e r ocker a r m s, br idges a n d pivot s.
(3) Rem ove t h e pu sh r ods.
(4) Rem ove t h e en gin e cylin der h ea d.
(5) P osit ion t h e pist on s on e a t a t im e n ea r t h e bot -
t om of t h e st r oke. Use a r idge r ea m er t o r em ove t h e
r idge fr om t h e t op en d of t h e cylin der wa lls. Use a
pr ot ect ive clot h t o collect t h e cu t t in gs.
(6) Ra ise t h e veh icle.
Fig. 62 Oil Pump Assembly
(7) Dr a in t h e en gin e oil.
(8) Rem ove t h e oil pa n a n d ga sket .
(9) Rem ove t h e con n ect in g r od bea r in g ca ps a n d
in ser t s. Ma r k t h e ca ps a n d r ods wit h t h e cylin der
bor e loca t ion . Th e con n ect in g r ods a n d ca ps a r e
st a m ped wit h a t wo let t er com bin a t ion (F ig. 63).
Fig. 63 Stamped Connecting Rods and Caps
(10) Lower t h e veh icle u n t il it is a bou t 2 feet fr om
t h e floor.
CAUTION: Ensure that the connecting rod bolts DO
NOT scratch the crankshaft journals or cylinder
walls. Short pieces of rubber hose, slipped over the
rod bolts will provide protection during removal.
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