DaimlerChrysler LH New Yorker 1994, Электронное руководство по обслуживанию

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COOLANT DEAERATION PRESSURE BOTTLE
This system works in conjunction with the coolant
deaeration pressure bottle pressure cap to keep the
coolant free of trapped air. It provides a volume for
expansion and contraction and provides a convenient
and safe method for checking coolant level and ad-
justing level at atmospheric pressure. It also provides
some reserve coolant to cover minor leaks and evapo-
ration or boiling losses (Fig. 5).
Refer to Coolant Level Check Service, Deaeration
and Pressure Cap sections for operation and service.
DEAERATION PRESSURE BOTTLE PRESSURE CAP
Deaeration bottle is equipped with a pressure cap
which releases pressure at some point within a range
of 117 kPa
6
7 kPa (17 psi
6
1 psi)(Fig. 6).
The system will operate at higher than atmo-
spheric pressure which raises the coolant boiling
point thus allowing increased radiator cooling capac-
ity.
There is a spring-loaded vent valve in the center of
the cap that allows the system to pressurize and
depressurize without creating a vacuum. If valve is
stuck open, coolant will escape to the overflow hose.
There is also a gasket in the cap to seal to the top of
the filler neck.
DEAERATION PRESSURE BOTTLE CAP TO
SEAL CHECK
The pressure cap upper gasket (seal) pressure relief
can be checked by removing cap (Fig. 7). Attach the
Radiator Pressure Tool to the cap and pump air into
the cap. Pressure cap upper gasket should relieve at
124 kPa (18 psi) and hold pressure at 110 kPa (16 psi)
minimum.
WARNING: THE WARNING WORDS DO NOT OPEN
HOT ON THE DEAERATION PRESSURE BOTTLE
CAP IS A SAFETY PRECAUTION. WHEN HOT, PRES-
SURE BUILDS UP IN COOLING SYSTEM. TO PRE-
VENT SCALDING OR INJURY, THE DEAERATION
PRESSURE BOTTLE CAP SHOULD NOT BE RE-
MOVED WHILE THE SYSTEM IS HOT AND/OR UN-
DER PRESSURE.
There is no need to remove the pressure cap at any
time except for the following purposes:
(1) Checking and adjust antifreeze freeze point.
(2) Refilling system with new coolant.
(3) Conducting service procedures.
(4) Checking for vacuum leaks.
WARNING: IF VEHICLE HAS BEEN RUN RECENTLY,
WAIT 15 MINUTES BEFORE REMOVING CAP. THEN
PLACE A SHOP TOWEL OVER THE CAP AND WITH-
OUT
PUSHING DOWN ROTATE IT COUNTER-
CLOCKWISE TO THE FIRST STOP. ALLOW FLUIDS
TO ESCAPE THROUGH THE OVERFLOW TUBE AND
WHEN THE SYSTEM STOPS PUSHING OUT COOL-
ANT AND STEAM AND PRESSURE DROPS, RE-
MOVE THE CAP COMPLETELY. SQUEEZING THE
RADIATOR INLET HOSE WITH A SHOP TOWEL (TO
CHECK PRESSURE) BEFORE AND AFTER TURNING
TO THE FIRST STOP IS RECOMMENDED.
PRESSURE TESTING DEAERATION PRESSURE
BOTTLE CAP
Dip the pressure cap in water, clean any deposits
off the vent valve or its seat and apply cap to end of
Radiator Pressure Tool. Working the plunger, bring
the pressure to 104 kPa (15 psi) on the gauge. If the
pressure cap fails to hold pressure of at least 117 kPa
(17 psi) replace cap. See CAUTION
If the pressure cap tests properly while positioned
on Radiator Pressure Tool (Fig. 7), but will not hold
pressure or vacuum when positioned on the deaera-
tion bottle, inspect the deaeration bottle neck and
cap gasket for irregularities that may prevent the
cap from sealing properly.
Fig. 5 Coolant Deaeration Pressure Bottle
Fig. 6 Deaeration Pressure Cap Filler Neck
7 - 14 COOLING SYSTEM