Refrigerant Circuit, Servicing; General Information - Audi Q7 2007 Repair Manual

15

Refrigerant Circuit, Servicing

⇒ "15.1 General Information", page 241
⇒ "15.2 Refrigerant Circuit, Servicing", page 242
⇒ "15.3 Refrigerant Lines, Disconnecting from Compressor and
Connecting", page 250
⇒ "15.4 Compressor, Removing and Installing", page 252
⇒ "15.5 Refrigerant Temperature Sensor G454 , Removing and
Installing", page 255
⇒ "15.6 Refrigerant Lines, Disconnecting from Condenser and
Connecting", page 256
⇒ "15.7 Condenser, Removing and Installing", page 258
⇒ "15.8 Connection Points of Refrigerant Lines, Loosening and
Assembling ", page 262
⇒ "15.9 Dryer Cartridge, Removing and Installing ", page 264
⇒ "15.10 Front Expansion Valve, Removing and Installing", page
269
⇒ "15.11 Refrigerant Lines from Rear Expansion Valve, Discon-
necting and Connecting ", page 272
⇒ "15.12 Rear Expansion Valve, Removing and Installing ", page
275
15.1

General Information

Note
Refrigerant in refrigerant circuit is never to be topped up (drain,
♦
evacuate and refill circuit). Refer to ⇒ Refrigerant R134a
Servicing; Rep. Gr. 87 ; Refrigerant Circuit (Refrigerant
R134a, Servicing; Refrigerant Circuit, Using Service Station).
Compressor is always driven when engine is running; there is
♦
no magnetic clutch. Engine is therefore not to be started un-
less refrigerant circuit has been properly assembled. If for
example the refrigerant lines are not connected to the com-
pressor and the engine is started then the compressor may be
destroyed by the build-up of internal heat. Such internal heat
generation results from the fact that - even with delivery ap-
proaching 0 % - the compressor is confronted with a fixed
resistance (sealed circuit).
To stop the compressor being destroyed when the refrigerant
♦
circuit is empty, it is designed such that delivery is reduced to
roughly 0 % and lubrication is maintained by way of an internal
oil circuit with the oil left in the compressor.
A specific quantity of refrigerant oil is filled in a compressor as
♦
replacement part, this equates to the total quantity of refriger-
ant oil in the refrigerant circuit in vehicles with only one A/C
unit. On vehicles with two A/C units (an additional rear A/C
unit), an additional quantity of refrigerant oil must be added to
the refrigerant circuit. Refer to ⇒ A/C System with Refrigerant
R134a; Rep. Gr. 87 ; Refrigerant Circuit Components, Re-
placing (A/C System with Refrigerant R134a; Refrigerant Cir-
cuit Components, Replacing).
Heating, Ventilation and Air Conditioning - Edition 04.2013
Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.
Audi Q7 2007 ➤
15. Refrigerant Circuit, Servicing
241