RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN 7 (2001)
Hose/Line HVAC: Description and Operation
A/C LINE COUPLERS
Spring-lock type refrigerant line couplers are used to connect many of the refrigerant lines and other components to the refrigerant system. These
couplers require a special tool for disengaging the two coupler halves.
The refrigerant lines and hoses are used to carry the refrigerant between the various air conditioning system components. A barrier hose design
with a nylon tube, which is sandwiched between rubber layers, is used for the R-134a air conditioning system on this vehicle. This nylon tube
helps to further contain the R-134a refrigerant, which has a smaller molecular structure than R-12 refrigerant. The ends of the refrigerant hoses are
made from lightweight aluminum or steel, and commonly use braze-less fittings.
Any kinks or sharp bends in the refrigerant plumbing will reduce the capacity of the entire air conditioning system. Kinks and sharp bends reduce
the flow of refrigerant in the system. A good rule for the flexible hose refrigerant lines is to keep the radius of all bends at least ten times the
diameter of the hose. In addition, the flexible hose refrigerant lines should be routed so they are at least 80 millimeters (3 inches) from the exhaust
manifold.
The spring-lock coupler is held together by a garter spring inside a circular cage on the male half of the fitting. When the two coupler halves are
connected, the flared end of the female fitting slips behind the garter spring inside the cage on the male fitting. The garter spring and cage prevent
the flared end of the female fitting from pulling out of the cage.
Two O-rings on the male half of the fitting are used to seal the connection. These O-rings are compatible with R-134a refrigerant and must be
replaced with O-rings made of the same material.
Secondary clips are installed over the two connected coupler halves at the factory for added blowoff protection. In addition, some models have a
plastic ring that is used at the factory as a visual indicator to confirm that these couplers are connected. After the coupler is connected, the plastic
indicator ring is no longer needed; however, it will remain on the refrigerant line near the coupler cage.
High pressures are produced in the refrigerant system when the air conditioning compressor is operating. Extreme care must be exercised to make
sure that each of the refrigerant system connections is pressure-tight and leak free. It is a good practice to inspect all flexible hose refrigerant lines
at least once a year to make sure they are in good condition and properly routed.
The refrigerant lines and hoses are coupled with other components of the HVAC system with peanut- block style fittings. A stat-O seal type flat
steel gasket with a captured compressible O-ring, is used to mate plumbing lines with A/C components to ensure the integrity of the refrigerant
system.
The refrigerant lines and hoses cannot be repaired and, if faulty or damaged, they must be replaced.
WARNING:
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THE AIR CONDITIONING SYSTEM CONTAINS REFRIGERANT UNDER HIGH PRESSURE. SEVERE PERSONAL INJURY
MAY RESULT FROM IMPROPER SERVICE PROCEDURES. REPAIRS SHOULD ONLY BE PERFORMED BY QUALIFIED
SERVICE PERSONNEL.AVOID BREATHING THE REFRIGERANT AND REFRIGERANT OIL VAPOR OR MIST. EXPOSURE
MAY IRRITATE THE EYES, NOSE, AND/OR THROAT. WEAR EYE PROTECTION WHEN SERVICING THE AIR
CONDITIONING REFRIGERANT SYSTEM. SERIOUS EYE INJURY CAN RESULT FROM DIRECT CONTACT WITH THE
REFRIGERANT. IF EYE CONTACT OCCURS, SEEK MEDICAL ATTENTION IMMEDIATELY.
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DO NOT EXPOSE THE REFRIGERANT TO OPEN FLAME. POISONOUS GAS IS CREATED WHEN REFRIGERANT IS
BURNED. AN ELECTRONIC LEAK DETECTOR IS RECOMMENDED. IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE THE WORK AREA BEFORE RESUMING SERVICE. LARGE AMOUNTS OF REFRIGERANT RELEASED IN A
CLOSED WORK AREA WILL DISPLACE THE OXYGEN AND CAUSE SUFFOCATION. THE EVAPORATION RATE OF
R-134a REFRIGERANT AT AVERAGE TEMPERATURE AND ALTITUDE IS EXTREMELY HIGH. AS A RESULT, ANYTHING
THAT COMES IN CONTACT WITH THE REFRIGERANT WILL FREEZE. ALWAYS PROTECT THE SKIN OR DELICATE
OBJECTS FROM DIRECT CONTACT WITH THE REFRIGERANT.
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THE R-134a SERVICE EQUIPMENT OR THE VEHICLE REFRIGERANT SYSTEM SHOULD NOT BE PRESSURE TESTED
OR LEAK TESTED WITH COMPRESSED AIR. SOME MIXTURES OF AIR AND R-134a HAVE BEEN SHOWN TO BE
COMBUSTIBLE AT ELEVATED PRESSURES. THESE MIXTURES ARE POTENTIALLY DANGEROUS, AND MAY RESULT
IN FIRE OR EXPLOSION CAUSING INJURY OR PROPERTY DAMAGE.
CAUTION:
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Liquid refrigerant is corrosive to metal surfaces. Follow the operating instructions supplied with the service equipment being used.
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Never add R-12 to a refrigerant system designed to use R-134a. Damage to the system will result.
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R-12 refrigerant oil must not be mixed with R-134a refrigerant oil. They are not compatible.
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Do not use R-12 equipment or parts on the R-134a system. Damage to the system will result.
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Do not overcharge the refrigerant system. This will cause excessive compressor head pressure and can cause noise and system failure.
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Recover the refrigerant before opening any fitting or connection. Open the fittings with caution, even after the system has been discharged.
Never open or loosen a connection before recovering the refrigerant.
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Do not remove the secondary retention clip from any spring-lock coupler connection while the refrigerant system is under pressure. Recover
the refrigerant before removing the secondary retention clip. Open the fittings with caution, even after the system has been discharged. Never
open or loosen a connection before recovering the refrigerant.
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The refrigerant system must always be evacuated before charging.
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Do not open the refrigerant system or uncap a replacement component until you are ready to service the system. This will prevent
