Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSNISSAN-DATSUN2004SENTRA L4-2.5L (QR25DE)REPAIR AND DIAGNOSISHEATING AND AIR CONDITIONINGCOUPLER HVACDESCRIPTION AND OPERATION
2004 Nissan-Datsun Sentra L4-2.5L (QR25DE)
Coupler HVAC: Description and Operation
2004 Nissan-Datsun Sentra L4-2.5L (QR25DE)SECTION Description and Operation
O-ring And Refrigerant Connection:
O-Ring Part Numbers And Specifications:
FEATURES OF NEW TYPE REFRIGERANT CONNECTION
The O-ring has been relocated. It has also been provided with a groove for proper installation. This eliminates the chance of the O-ring being caught in, or damaged by, the mating part. The sealing direction of the O-ring is now set vertically in relation to the contacting surface of the mating part to improve sealing characteristics.
The reaction force of the O-ring will not occur in the direction that causes the joint to pull out, thereby facilitating piping connections.
WARNING: Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is less than atmospheric pressure. Then gradually loosen the discharge side hose fitting and remove it.
CAUTION: When replacing or cleaning refrigerant cycle components, observe the following:
* When the compressor is removed, store it in the same position as it is when mounted on the car. Failure to do so will cause lubricant to enter the low pressure chamber.
* When connecting tubes, always use a torque wrench and a back-up wrench.
* After disconnecting tubes, immediately plug all openings to prevent entry of dirt and moisture.
* When installing an air conditioner in the vehicle, connect the pipes as the final stage of the operation. Do not remove the seal caps of pipes and other components until just before required for connection.
* Allow components stored in cool areas to warm to working area temperature before removing seal caps. This prevents condensation from forming inside A/C components.
* Thoroughly remove moisture from the refrigeration system before charging the refrigerant.
* Always replace used O-rings.
* When connecting tube, apply lubricant to circle of the O-rings shown in illustration. Be careful not to apply lubricant to threaded portion.
Lubricant Name: ......... Nissan A/C System Oil Type R
Part Number: .............. KLH00-PAGR0
* O-ring must be closely attached to dented portion of tube.
* When replacing the O-ring, be careful not to damage O-ring and tube.
* Connect tube until you hear it click, then tighten the nut or bolt by hand until snug. Make sure that the O-ring is installed to tube correctly.
* After connecting line, conduct leak test and make sure that there is no leakage from connections. When the gas leaking point is found, disconnect that line and replace the O-ring. Then tighten connections of seal seat to the specified torque.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.