Refrigerant Circuit
Refrigerant Circuit
=> [ Component Overview ]
=> [ Refrigerant Circuit O-Ring Seals ]
• Repair work on refrigerant circuit. Refer to => [ Refrigerant Circuit, Servicing ] Refrigerant Circuit, Servicing.
• All work or components marked with 1) can be repaired, replaced or performed in any workshop (work that does not pertain to refrigerant circuit).
• All refrigerant circuit components not marked with 1) as well as all coolant hoses and lines can only be serviced or replaced in an A/C system service point workshop.
• In vehicles with an 8-cyl. engine, the compressor is driven by a shaft not a belt.
Component Overview
HD = High-pressure end
ND = Low-pressure end
1 - A/C Compressor Regulator Valve (N280)
• Checking activation and function. Refer to => [ Test Step 6 ] Climatronic Control Module A/C Control Head Electrical Test 1)
2 - Compressor
• Remove the compressor from the bracket and reinstall it. Refer to => [ Compressor, Removing from Bracket ] Compressor, Removing From Bracket and 1)
• When installing refrigerant lines/hoses and pertaining bracket, make sure there is a sufficient gap between belt, bracket and belt pulley
• The type of compressor differs depending on the engine (installed on the right or left of the engine).
• Depending on the country version, various compressor types are installed (e.g. "Denso" type designation "6 SEU" for Europe and "7 SEU" for countries with a hot climate).
3 - Belt Pulley/Drive Unit - Compressor For Engine
• Remove and install the ribbed belt. Refer to 1) and => Engine Mechanical Engine
• Ribbed belt allocation.
• Check and replace the compressor drive unit. Refer to => [ Compressor Drive Unit ] Compressor Drive Unit
• A rubber element is installed between the belt pulley/drive unit and the drive shaft of the compressor to protect the belt/gear drive in the event that the compressor is seized or does not move freely.
• If compressor is not operating smoothly, rubber element interrupts power transmission to compressor.
• A rubber element is installed between the engine and the compressor to protect the gear drive if the compressor is blocked or not operating smoothly.
• Rubber element reduces vibration which may occur during compressor operation (damper function in the event of torque fluctuations).
4 - Oil Drain Plug
5 - High Pressure Relief Valve
6 - Connection With Valve
7 - High Pressure Sensor (G65 ) 1)
• Removing and installing, refer to => [ High Pressure Sensor ] Service and Repair
• Checking signal, refer to => [ Test Step 5 ] Climatronic Control Module A/C Control Head Electrical Test
8 - Condenser
9 - Cap
• With seal
• Always screw on
10 - Service Connection
• High pressure side
• Used for measuring, discharging and recharging by A/C system service point workshops
11 - Bolts In Refrigerant Line
12 - Restrictor
• Installed in the threaded connection - item 11
13 - Evaporator
14 - Service Connection
• Low pressure side
• Used for measuring and discharging by A/C system service point workshops
15 - Cap
• With seal
• Always screw on
16 - Reservoir
Refrigerant Circuit O-Ring Seals
• Only to be used once; always replace.
• Lightly moisten with refrigerant oil before fitting.
• Pay attention to correct positioning on pipe/in groove.
• Ensure cleanliness when working.
• Install only O-rings that are resistant to refrigerant R134a and corresponding refrigerant oil. These O-rings are color-coded to avoid mistakes (currently " red", "light purple" and "dark purple").
• In addition to the color-coded O-ring seals, use is also made at the factory of black O-ring seals for certain connections.
• The O-ring dimensions - a - and - b - are different depending on installation location.
• In January 2003, the connections from the refrigerant lines to various components (condenser, evaporator, etc.) were changed from a radial/axial seal to a radial seal. Only components with the same type of seal and the provided O-ring seals (various versions) may be installed together. If components with different seals are installed, the connection points cannot be sealed.