Propylene - glycol / Ethylene - glycol Mixtures - Should Not
Be Used in Chrysler Vehicles
Propylene-glycol/et hylene-glycol Mixt ures can
cause the destabiliza tion of various cor rosion inhibi-
tors, cau sing damage to the various cooling syst em
components. Also, on ce ethylene-glycol and propy-
lene-glycol based coolant s are mixed in the vehicle,
conven tional met hods of deter min ing fr eeze point will
not be accura te. Bot h the refra ctive in dex a nd spe-
cific gravit y differ between ethylen e glycol and pr opy-
lene glycol.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
DI AGN OSI S AN D T EST I N G
COOLING SYSTEM LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detect ion addit ive is available throu gh th e
pa rts depart ment t hat ca n be added to cooling sys-
tem. Th e additive is highly visible un der u ltraviolet
light (black light). Pour one ounce of additive in to
coolin g system. Place heater control unit in HEAT
position . Start and operate en gin e u ntil radiator
upper hose is wa rm to touch. Aim the commercially
ava ila ble black ligh t tool a t componen ts to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
The black light ca n be used in conjunction with a
pressure t ester t o determine if any externa l leaks
exist (F ig. 1).
PRESSURE TESTER METHOD
The engine should be at nor mal operating temper-
ature. Recheck t he system cold if cause of coolant
loss is not locat ed du ring the wa rm engine examina-
tion.
WARNING: Hot, pressurized coolant can cause
injury by scalding.
Carefully rem ove coolant r ecovery pressure con -
tainer ca p a nd check coolant level. Pu sh down on cap
to disenga ge it fr om stop tabs. Wipe inside of con-
tainer and exa mine lower in side sealing sea t for
nicks, cracks, pain t, dirt and solder residue. Inspect
radiator-to- pressure container h ose for interna l
obstructions. Insert a wir e th rough the hose t o be
su re it is not obstr ucted.
In spect cams on outside of pressure container. If
cams are dam aged, seating of pressure cap valve and
tester sea l will be affected.
Attach pressur e test er (7700 or an equivalent ) t o
coolan t pressure container (Fig. 2).
Fig. 1 Leak Detection Using Black Light - Typical
1 - TYPICAL BLACK LIGHT TOOL
7 - 10 ENGINE VA
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