Coolant-Adding Additional; Coolant-Level Check; Cooling System-Reverse Flushing - Jeep Cherokee 1999 Electronic Service Manual

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SERV I CE PROCEDU RES (Cont inue d)
COOLANT—ADDING ADDITIONAL
D o n o t re m o v e ra d ia to r c a p to a d d c o o la n t to
s y s te m . Wh en a ddin g coola n t t o m a in t a in cor r ect
level, do so a t coola n t r eser ve/over flow t a n k. Use a
50/50 m ixt u r e of et h ylen e-glycol a n t ifr eeze con t a in in g
Alu ga r d 340-2 a n d low m in er a l con t en t wa t er.
Rem ove r a dia t or ca p on ly for t est in g or wh en r efill-
in g syst em a ft er ser vice. Rem ovin g ca p u n n ecessa r ily
ca n ca u se loss of coola n t a n d a llow a ir t o en t er sys-
t em , wh ich pr odu ces cor r osion .
COOLANT—LEVEL CHECK
Th e coolin g syst em is closed a n d design ed t o m a in -
t a in coola n t level t o t op of r a dia t or.
WARNING: DO NOT OPEN RADIATOR DRAINCOCK
WITH ENGINE RUNNING OR WHILE ENGINE IS HOT
AND COOLING SYSTEM IS UNDER PRESSURE.
Wh en veh icle ser vicin g r equ ir es a coola n t level
ch eck in r a dia t or, dr a in sever a l ou n ces of coola n t
fr om r a dia t or dr a in cock. Do t h is wh ile obser vin g
coola n t r eser ve/over flow syst em t a n k. Th e coola n t
level in r eser ve/over flow t a n k sh ou ld dr op sligh t ly. If
n ot , in spect for a lea k bet ween r a dia t or a n d coola n t
r eser ve/over flow syst em con n ect ion . Rem ove r a dia t or
ca p. Th e coola n t level sh ou ld be t o t op of r a dia t or. If
n ot a n d if coola n t level in r eser ve/over flow t a n k is a t
ADD m a r k, ch eck for :
• An a ir lea k in coola n t r eser ve/over flow t a n k or
it s h ose
• An a ir lea k in r a dia t or filler n eck
• Lea k in pr essu r e ca p sea l t o r a dia t or filler n eck
COOLING SYSTEM—DRAINING AND FILLING
DRAINING
WARNING: DO NOT
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAINCOCK WITH SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
DO NOT WASTE r eu sa ble coola n t . If t h e solu t ion
is clea n , dr a in t h e coola n t in t o a clea n con t a in er for
r eu se.
(1) Rem ove r a dia t or pr essu r e ca p.
(2) F or a ccess t o r a dia t or dr a in cock (F ig. 15),
r em ove r a dia t or gr ille m ou n t in g scr ews a n d r em ove
gr ill. Refer t o Gr ou p 23, Body for cor r ect pr ocedu r e.
(3) At t a ch on e en d of a 24 in ch lon g X 1/4 in ch ID
h ose t o t h e r a dia t or dr a in cock. P u t t h e ot h er en d in t o
a clea n con t a in er. Open dr a in cock a n d dr a in coola n t
fr om r a dia t or.
REMOVE THE CYLINDER
Fig. 15 Radiator Petcock—2.5L/4.0L (LHD/RHD)
(4) Dr a in coola n t fr om en gin e by r em ovin g t h e
dr a in plu g a n d coola n t t em per a t u r e sen sor on left
side of block.
REFILLING
(1) Tigh t en t h e r a dia t or pet cock a n d t h e cylin der
block dr a in plu g(s).
(2) In st a ll gr ille.
(3) F ill syst em u sin g a 50/50 m ixt u r e of wa t er a n d
a n t ifr eeze a s descr ibed in t h e Coola n t sect ion of t h is
gr ou p. F ill r a dia t or t o t op a n d in st a ll r a dia t or ca p.
Add su fficien t coola n t t o r eser ve/over flow t a n k t o
r a ise level t o F ULL m a r k.
(4) Wit h h ea t er con t r ol u n it in t h e H E AT posit ion ,
oper a t e en gin e wit h r a dia t or ca p in pla ce.
(5) Aft er en gin e h a s r ea ch ed n or m a l oper a t in g
t em per a t u r e, sh u t en gin e off a n d a llow it t o cool.
(6) Add coola n t t o r eser ve/over flow t a n k a s n eces-
sa r y. On ly a d d c o o la n t w h e n th e e n g in e is c o ld .
Co o la n t le v e l in a w a rm e n g in e w ill be h ig h e r
d u e to th e rm a l e x p a n s io n .
COOLING SYSTEM—REVERSE FLUSHING
CAUTION: The cooling system normally operates at
97-to-124 kPa (14- to-18 psi) pressure. Exceeding
this pressure may damage the radiator or hoses.
Rever se flu sh in g of t h e coolin g syst em is t h e for c-
in g of wa t er t h r ou gh t h e coolin g syst em . Th is is don e
u sin g a ir pr essu r e in t h e opposit e dir ect ion of n or m a l
coola n t flow. It is u su a lly on ly n ecessa r y wit h ver y
dir t y syst em s wit h eviden ce of pa r t ia l plu ggin g.
COOLING SYSTEM 7 - 21