Where is the low charge nipple for the AC system located on a 2001 Ford Expedition?
How to Recharge Your Car's Air Conditioner By Larry
Carley c2007 LOW REFRIGERANT If your air conditioner is
not cooling well because the system is low on refrigerant,
recharging the system with refrigerant should restore normal
operation. This can usually be done with a few cans of refrigerant
and a simple service hose connection. RECHARGING PRECAUTIONS
First, wear safety glasses to protect your eyes. Also avoid skin
contact with refrigerant. The chilling effect of spilled
refrigerant can cause instant frostbite on bare skin or eyes!
WHAT TYPE OF REFRIGERANT? Next, you need to figure out what
type of refrigerant your vehicle requires:
On 1995 and newer passenger cars and light trucks, the correct
refrigerant is R134a. DO NOT use any other type of refrigerant.
On most 1994 and older passenger cars and light trucks, the
original refrigerant was R12. R12 is no longer available to
do-it-yourselfers and is very expensive. When older vehicles with
R12 A/C systems need refrigerant, they can be refilled with
recycled R12 from other older cars (this requires taking your car
to a repair shop for professional service), or with some
alternative refrigerant other than R12, or with R134a (which
requires certain modifications). CAUTION: Mixing different
types of refrigerants is NOT recommended. Use the same type of
refrigerant that is already in the system unless you are converting
an older R12 system to R134a or another refrigerant.
WARNING: Flammable refrigerants are illegal. DO NOT use any
type of flammable refrigerant (propane, butane or flammable
hydrocarbons). Click here for more information about retrofitting
older vehicles with R12 A/C systems to R134a. LOCATE THE SERVICE
FITTINGS Next, you need to locate the service fittings on the
A/C system. There are two: a LOW side fitting and a HIGH side
fitting. The LOW side fitting is usually located on the suction
hose or line that goes from the accumulator to the compressor. The
HIGH side fitting is located on the line that goes from the
compressor to the condenser.
"mso-bidi-font-weight: normal">R12 Low Side 7/16 in. threaded
"mso-bidi-font-weight: normal">R134 Low Side 13mm
High Side 3/8 in. threaded
"mso-bidi-font-weight: normal">R134A High Side 16mm
Quick-disconnect On older R12 systems, the LOW and HIGH
pressure service fittings are screw-type Schrader valves. On newer
R134a systems, the LOW and HIGH side service fittings are
quick-connect style fittings. The LOW pressure fitting is SMALLER
than the HIGH pressure fitting. RECHARGE PROCEDURE 1.
Connect the recharge service hose and valve to a can of
2. Turn the valve on the service hose to puncture the top of the
3. SLOWLY turn the valve back out to release a small amount of
refrigerant into the hose. This will blow air out of the hose
(which you do not want in your A/C system).
4. Close the valve so no more refrigerant escapes, then quickly
connect the other end of the service hose to the LOW pressure
service fitting on the A/C system.
CAUTION: DO NOT connect a can of refrigerant to the HIGH
side service fitting. The operating pressure inside the A/C system
when it is running may exceed the burst strength of the can,
causing the can to explode! This should be impossible to do because
the service hose for recharging the A/C system will only fit the
smaller LOW pressure service fitting. Even so, you should be aware
of the danger.
5. Hold the can UPRIGHT so no refrigerant liquid enters the
service hose. You only want VAPOR to be pulled into the A/C system
(the compressor may be damaged if it sucks in a big dose of
6. OPTIONAL BUT HIGHLY RECOMMENDED: You should use a
gauge to monitor the recharging process. Though not absolutely
necessary, a gauge will help you recharge your A/C system more
accurately, and reduce the chance of undercharging or overcharging
(either of which will reduce cooling performance).
A high pressure A/C gauge can be connected to the HIGH pressure
service fitting, or a low pressure A/C gauge to the LOW pressure
service fitting, or gauges can be attached to both fittings (that
is what professional technicians do).
NOTE: Some DIY recharging kits include a low pressure gauge on
the service hose or on a trigger-grip style can dispenser.
7. Start the engine and turn the A/C on MAX/HIGH.
8. NOTE: The compressor may not engage if the system is too low
on refrigerant. The low pressure cutout switch will prevent the
compressor from running if the system is too low on refrigerant
(this is done to protect the compressor from damage due to a lack
of proper lubrication). The compressor must be running to suck
refrigerant through the service hose into the system. So if it is
not engaging when you turn the A/C on, you may have to supply
battery voltage directly to the compressor clutch using a fused
jumper wire. Look for a single wire connector near the front of the
compressor, unplug it and hook up a jumper wire to the battery
POSITIVE terminal. This should cause the clutch to engage and the
compressor to run.
9. OPEN the valve on the service hose so refrigerant vapor will
flow from the can into the A/C system. It may take up to 10 minutes
or more per can to suck all of the refrigerant out of the can into
the A/C system. Feel the air coming out of the ducts inside the
vehicle. It should be getting colder.
10. If you are using a high or low pressure gauge (or both) to
monitor recharging, look at the gauge(s).
LOW pressure gauge: When the reading is between 25 and
40 psi with the A/C running, STOP. The system is fully
charged and should be cooling normally. DO NOT add any more
refrigerant. If the gauge is over 50 psi, you have overcharged the
system with too much refrigerant.
High pressure gauge: When the reading gets up around
200 to 225 psi (R12), or225 to 250 psi (R134a),
STOP. The system is fully charged and should be cooling
normally. DO NOT add any more refrigerant.
NOTE: The high and low pressure readings will vary
depending on the system and ambient temperatures (higher
temperatures cause higher system pressure readings).
Refer to the vehicle manufacturer specifications for normal
system operating pressures, and the total refrigerant capacity of
the system. Most newer passenger car A/C systems do not hold much
refrigerant (only 14 to 28 oz.), so you don't want to add too much
if the system is low. One can of R134a typically holds 12 oz. of
11. If the system needs more refrigerant after adding one can,
you can add a second can. CLOSE the valve on the service hose, then
disconnect the hose from the empty can, screw a new can onto the
service hose valve, turn the valve to puncture the new can, then
turn the valve all the way back out again so refrigerant can flow
through the hose into the A/C system.
When you have finished, turn the engine off. CLOSE the valve on
the can of refrigerant before disconnecting the service hose from
the LOW pressure fitting (in case there is any refrigerant left in
the can). Don't vent any leftover refrigerant from the can. Leave
the service hose attached to the can with the valve closed so you
can save the refrigerant for a future recharge.
Remember to replace the plastic caps over the service fittings,
and remove the jumper wire from the compressor if you had to jump
it to make it run. IF THE A/C SYSTEM STOPS BLOWING COLD AIR
AFTER A FEW DAYS, WEEKS OR MONTHS If your A/C stops blowing
cold air several days, weeks or months after you recharged it, it
means the system has a leak and the refrigerant is escaping. You
should add some leak detection dye to the system to find the leak.
The leak should then be repaired before the system is recharged
again; otherwise you are just wasting your time recharging the
system over and over again.