Grand Cherokee 2WD L6-4.0L VIN S (1997)
Hose/Line HVAC: Service Precautions
The air conditioning hoses used on this vehicle are made from reinforced rubber with a nylon liner on the inner walls. The ends of the A/C hoses are
made from light-weight aluminum and use new fittings.
The A/C hoses use special connectors called QUICK CONNECTS. Never attempt to disconnect a quick connect without discharging the air conditioning
system. All quick connects use two 0-rings to seal the connection. The 0-rings are made from a special type of rubber that is not affected by R-134a
refrigerant. If 0-ring replacement is required be sure to use the correct type of 0-ring. Failure to use the correct type of 0-ring will cause the connection to
leak within a short period of time.
Kinks in the refrigerant tubing or sharp bends in the refrigerant hose lines will greatly reduce the capacity of the entire system. High pressures are
produced in the system when it is operating. Extreme care must be exercised to make sure that all connections are pressure tight. Dirt and moisture can
enter the system when it is opened for repair or replacement of lines or components. The refrigerant oil will absorb moisture readily out of the air. This
moisture will convert into acids within a closed system.
CAUTION: DO NOT use R-12 equipment or parts on the R-134a system. Damage to the system will result.
1. The refrigerant system must be completely discharged into a refrigerant recovery/recycling device before opening any fitting or connection. Open
fittings with caution even after the system has been discharged. If any pressure is noticed as a fitting is loosened, allow trapped pressure to bleed
off very slowly into an approved recycling device.
2. DO NOT discharge refrigerant into the atmosphere. Use an R-134a refrigerant recycling device that meets SAE Standard J2210.
3. A good rule for the flexible hose lines is to keep the radius of all bends at least 10 times the diameter of the hose. Sharper bends will reduce the
flow of refrigerant. The flexible hose lines should be routed so they are at least 80 mm (3 in) from the engine exhaust manifold. Inspect all flexible
hose lines to make sure they are in good condition and properly routed.
4. The use of correct tools when making connections is very important. Improper tools or improper use of tools can damage the fittings.
5. The A/C system will remain chemically stable as long as pure, moisture-free R-134a refrigerant oil is used. Abnormal amounts of dirt, moisture or
air can upset the chemical stability. This condition could cause operational troubles or even serious damage if present in more than very small
quantities.
6. When it is necessary to open the refrigeration system, have everything needed to service the system ready. The system should not be left open any
longer than necessary. Cap or plug all lines and fittings as soon as they are opened to prevent the entrance of dirt and moisture. All lines and
components in parts stock should be capped or sealed until they are ready to be used.
7. All tools, including the refrigerant recycling equipment, the manifold gauge set and test hoses should be kept clean and dry. All tools and
equipment must be designed for the R-134a refrigerant.
