Dodge Sprinter 2006 Manual page 842

7 - 20 ENGINE
Fig. 11 Radiator Pressure Cap - Typical
1 - FILLER NECK SEAL
2 - VACUUM VENT VALVE
3 - PRESSURE RATING
4 - PRESSURE VALVE
OPERA TION
A ven t va lve in t h e cen t er of t h e ca p will r em a in
sh u t a s lon g a s t h e coolin g syst em is pr essu r ized. As
t h e coola n t cools, it con t r a ct s a n d cr ea t es a va cu u m
in coolin g syst em . Th is ca u ses t h e va cu u m va lve t o
open a n d coola n t in r eser ve/over flow t a n k t o be
dr a wn t h r ou gh con n ect in g h ose in t o r a dia t or. If t h e
va cu u m va lve is st u ck sh u t , or over flow h ose is
kin ked, r a dia t or h oses will colla pse on cool-down .
DIAGNOSIS AND TESTING - RADIA TOR PRES-
SURE CAP
Rem ove ca p fr om r a dia t or. Be su r e t h a t sea lin g
su r fa ces a r e clea n . Moist en r u bber ga sket wit h wa t er
a n d in st a ll t h e ca p on pr essu r e t est er Tool 7700 or a n
equ iva len t (F ig. 12).
Fig. 12 Pressure Testing Radiator Pressure Cap -
1 - PRESSURE CAP
2 - TYPICAL COOLING SYSTEM PRESSURE TESTER
Oper a t e t h e t est er pu m p a n d obser ve t h e ga u ge
poin t er a t it s h igh est poin t . Th e ca p r elea se pr essu r e
sh ou ld be 124-145 kP a (18-21 psi). Th e ca p is sa t is-
fa ct or y wh en t h e pr essu r e h olds st ea dy. It is a lso
good if it h olds pr essu r e wit h in t h e 124-145 kP a
(18-21 psi) r a n ge for 30 secon ds or m or e. If t h e
poin t er dr ops qu ickly, r epla ce t h e ca p.
CAUTION: Radiator pressure testing tools are very
sensitive to small air leaks, which will not cause
cooling system problems. A pressure cap that does
not have a history of coolant loss should not be
replaced just because it leaks slowly when tested
with this tool. Add water to tool. Turn tool upside
down and recheck pressure cap to confirm that cap
needs replacement.
WAT ER PU M P
REMOVAL
WARNING: Risk of injury to skin and eyes from
scalding with hot coolant. Risk of poisoning from
swallowing coolant. Do not open cooling system
unless coolant temperature is below 90°C (194°F)).
Open cap slowly to release pressure. store coolant
in suitable and appropriately marked container.
Wear protective gloves, clothes and eye wear.
Typical
VA