A/C - Description of R-134A System Changes
Classification: HA93-019Section: Air Conditioner
Reference: TECHNICAL BULLETIN NTB93-163
Models: 1994 Sentra
Date: November 9, 1993
1994 SENTRA A/C CHANGES FOR R-134a REFRIGERANT
APPLIED MODEL:
1994 Sentra (B13)
SERVICE INFORMATION
As part of Nissan's ongoing concern for the environment, the 1994 Sentra A/C system is designed for the use of R-134a refrigerant. This new refrigerant does not deplete the ozone in the upper atmosphere.
Technical Bulletin NTB93-001 (HA93-001) "A/C System Changes for R-134a Refrigerant (All Models)" includes general information concerning R-134a A/C systems while this bulletin describes specific details of the 1994 Sentra R-134a A/C system. Use this bulletin along with NTB93-001 for complete information concerning the 1994 Sentra R-134a A/C system.
Important Points:
^ The Sentra R-134a Port/Dealer A/C systems apply to 1994 model year. Sentras only. The Sentra R-134a system should not be installed in 1993 or earlier Sentra vehicles because engine overheating could result on some models.
^ The 1994 Sentra condenser fans for the GA16DE engine have been improved to withstand higher engine compartment temperatures. Only 1994 condenser fans should be used with the Sentra R-134a A/C system -- 1993 and earlier fans must not be used.
^ The R-134a systems have no sight glass because R-134a and the PAG lubricants do not exhibit "clear sight glass" characteristics, even when properly charged.
^ The 1994 Sentra R-134a system uses Nissan A/C System Oil Type R, P/N KLH00-PAGRO.
^ If an R-134a system is suspected to be low on refrigerant charge, perform a system leak check using the R-134a leak detector (J-39400). After repairing any leaks found, evacuate and charge the system using the ACR4 equipment.
^ The Sentra R-134a refrigerant components can be identified by all R-134a label on the component.
General Precautions
^ R-12 refrigerant and R-134a refrigerant must never be mixed, even in the smallest amounts, because they are incompatible with each other. If the refrigerants are mixed, compressor failure is likely to occur.
^ Use only Nissan A/C System oil Type R for the Sentra R-134a A/C system and Sentra R-134a components. If other lubricants are used, compressor failure is likely to occur.
^ Since R-134a lubricant absorbs moisture from the atmosphere at a rapid rate, the following handling precautions must be observed:
^ When removing refrigerant components from a vehicle, immediately cap (seal) the component to minimize the entry of moisture from the atmosphere.
^ When installing refrigerant components onto a vehicle, do not remove the caps (unseal) until just before connecting the components. Also, complete the connection of all refrigerant loop components without delay to minimize the entry of moisture into the system.
^ Use only the specified lubricant from a sealed container. Containers must be resealed immediately after dispensing the lubricant. Lubricant in containers which aren't properly sealed will become moisture saturated, and should be properly disposed of.
^ Avoid breathing A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose and throat. To remove R-134a from the A/C system, use service equipment certified to meet the requirements of SAE J2210 (R-134a recycling equipment).
^ If accidental system discharge occurs, ventilate the work area before resuming service. Additional health and safety information may be obtained from the refrigerant and lubrication manufacturer's.
^ Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or air conditioning system.
^ Do not introduce compressed air into any refrigerant container or refrigerant component because contamination will occur.
^ R-134a in the presence of oxygen and under pressure may form a combustible mixture. Never introduce compressed air into any R-134a container, cylinder, A/C component, recover/recycle equipment, or other service equipment. This includes "empty" containers.
WARRANTY INFORMATION
For "Evacuate/Recharge" operations involving R-134a charged A/C systems, OP Code TB777A must be used instead of the more familiar R-12 OP Code TB888A.