Diesel Data: Automotive Repair

A/C - Hiss Noise

Bulletin 85-1-15A

Date May, '85

Ref. No. 85-131A-1
SUBJECT: AIR CONDITIONING "HISS" NOISE

MODELS AFFECTED: 1985 SOMERSET REGAL


NOTICE: This bulletin supersedes 85-1-15 dated February 1985 for text correction. Please discard original bulletin and replace it with this one.


CONDITION:

Air conditioning system may make a "hiss" noise during idle and low speed conditions with the A/C "on". The sound generally comes from the center of the instrument panel and through the air outlets. The noise may not occur during highest ambient temperature conditions. Affected vehicles: prior to (VIN 401300).

CAUSE:

Refrigerant flowing through the orifice located in the evaporator inlet tube at the dash is the source of the "hiss".

AIR CONDITIONING SYSTEM:




CORRECTION:

1. Follow procedure outlined in Section 1B, Air Conditioning, 1985 Chassis Service Manual for discharging system.

2. Remove the orifice in the evaporator inlet tube at the dash pass-thru location and discard. Discard the forward clip.

3. Remove the condenser outlet-evap inlet tube assembly (P/N 10031683). Discard, and replace with P/N 10038431, Tube and Orifice Assembly. Use refrigerant lube on O-rings and torque bolts to 12 N-m (9 ft.lbs.) on the condenser end and 17 N-m (12 ft.lbs.) on the evaporator (dash) end. Rear tube clip must be reinstalled.

4. Evacuate and recharge.

WARRANTY INFORMATION

Labor Operation: T3136
Labor Time: 1.5 Hrs.. (Includes System Recharge)
Trouble Code: 92