Auto Climate Control Modifications/Diagnosis/Repair (83/36A)

Publication date: 1983-09-01
Reference number: 83/36A

AUTO CLIMATE CONTROL MODIFICATIONS/DIAGNOSIS/REPAIR

TECHNICAL SERVICE BULLETIN

Reference Number(s): 83/36A, Date of Issue: September, 1983
Superceded Bulletin(s): 83/36a

MODIFICATIONS AND WORK INSTRUCTIONS FOR AUTOMATIC CLIMATE/HEATING CONTROL

Model(s): All Mercedes Benz Models (except 190 Series)

Group: Climate Control

Bulletin No.: 83/86b

Date: September, 1983 (supersedes 83/36a)

SERVICE INFORMATION

Evaporator Manufacturer Identification Model 123 with AC and/or ACC.
Modified Receiver-Dryer Models 107, 123 and 126.
Repair and/or Replacement of Internally Damaged Refrigerant Compressors - Models 107, 123 and 126.
Air Blowing Constantly fro Defroster Outlets - Model 107.

A. EVAPORATOR MANUFACTURER IDENTIFICATION MODEL 123 WITH AC AND/OR ACC

Evaporators made by two manufacturers (Behr and Siemens/Thermal) are used in the manual air conditioning and automatic climate control systems. These evaporators arc not interchangeable in terms of spare parts replacement. The evaporator manufacturer can be visually identified by removing the glove compartment to insure that the proper evaporator is ordered/installed.

Evaporator for A/C system made by Behr: Lever of main air flap without part number. Additional part number label attached as of 8/80.

Evaporator for A/C system made by Siemens/Thermal: Lever of main air flap has part number.

Evaporator for ACC system made by Behr: Part number label attached and main air flap lever is white.

Evaporator for ACC system made by Siemens/Thermal: Main air flap lever is black.

B. MODIFIED RECEIVER-DRYER MODELS 107 AND 126, 123 (WITH ACC/AC-123.123)

Since October 1981, receiver-dryers with pressure relief valve were installed. This valve will discharge refrigerant at approximately 40 +/- 5 bar / 580 +/- 73 psi and will close again at approximately 5 bar / 73 psi below opening pressure. This will prevent the discharging of the entire refrigerant charge. The pressure relief valve can be replaced by itself.

NOTE: The new pressure relief valve cannot be installed on the previous receiver-dryer with temperature sensitive pressure relief plug due to a modified seal and assembly thread.

Since November 1981, a 52°C auxiliary fan cut-in switch has been installed on the receiver dryer same as on diesel models. Previous cut-in temperature was 62°C. When making repairs use only the 52°C switch.

PARTS INFORMATION

PART NAME	PART NUMBER	MODEL
Receiver-dryer with	126 830 01 83	126
pressure relief valve	123 830 06 83	123
107 830 09 83*		107**
Pressure relief valve	000 830 32 84	107, 123, 126
52°C temperature switch	000 820 80 10	107, 123, 126
*Will be supplied after depletion of 107 830 07 83 stock.
**Observe chassis end number in spare parts microfiche.

C. REPAIR AND/OR REPLACEMENT OF INTERNALLY DAMAGED REFRIGERANT

COMPRESSORS - MODELS 107,123 AND 126

York Refrigerant Compressor

Always install a suction strainer into suction port during repair and replacement of this type of compressor.
Strainers are available as separate spare parts.
A strainer is included in the valve plate/head gasket kit and with a new compressor.
With a new compressor also replace the receiver-dryer.
Always replace the expansion valve, if compressor had broken internal parts. Do not replace expansion valve if compressor is replaced for other reasons.
Refrigerant lines connected to compressor may be reused if suction strainer is installed and lines are flushed clean.

PARTS INFORMATION FOR YORK COMPRESSOR

PART NAME	PART NUMBER
York compressor with strainer (no clutch)	002 131 43 01
Valve plate with gaskets and strainer	000 586 34 13
Strainer only	000 131 04 34

Delco R4 and Frigidaire A6 Compressors

IMPORTANT:

When replacing compressors of this type due to seizing (broken internal parts), also replace the connected high pressure and suction lines.
NOTE: This prevents future compressor damage from particles lodged in old refrigerant lines that remain even after flushing.
Always replace expansion valve and receiver dryer when replacing a compressor that had broken internal parts.

PARTS INFORMATION

Part Name	Part Number
Frigidaire A6 Compressor (metric-w/o clutch)	903 131 25 01
Frigidaire A6 Compressor (SAE w/o clutch)	002 131 46 01
Delco R4 Compressor (metric-w/o clutch)	903 131 05 01

D. AIR BLOWING CONSTANTLY FROM DEFROSTER OUTLETS - MODEL 107

If air continues to exit from the defroster outlets, with buttons "Normal" or "EC" engaged and the system is in the cooling mode, the linkage attachment eyelet on the left defroster flap may be broken off.

NOTE: It is not necessary to replace the left flap. Both right and left flaps are identical and need only to be exchanged from side to side. Short-cut methods involving replacement of only the left flap by defroster duct removal are not allowed since complete re-attachment of the duct is not possible. Also, the chances for dropping a shaft bushing are greatly increased. Both conditions will lead to future noise complaints.

Exchanging Air Flaps

Remove instrument panel,
Remove clip on left and right side of air duct.
Pull flap shaft (common shaft for right and left flap out to the right, but only far enough to allow the flaps to be removed.
CAUTION: Do not drop the shaft end bushings into the housing when removing flaps. If a bushing is dropped into the housing it must be removed to prevent future noise complaints.
Examine the eyelet on the flap removed from the right side for any signs of cracks or damage. If none, exchange left with right air flap and reinstall shaft and clips.
Check to be sure that the flaps open and close without binding. If a new attachment rivet is needed, use part no. 000 990 34 92.
The remaining re-installation is performed in reverse order.

NOTE: To prevent flap damage during reassembly before installing the instrument cluster, apply vacuum to the element to close the flap. Keep the flap in this position by locking the linkage of the vacuum element with a wedge. After the instrument panel is installed, remove the wedge.