Home/Audi/A8/Audi A8 D2 (1997-1999)/Repair manual/Air Conditioning/Pump valve unit, replacing

Contents

Wiring diagrams Section: Air Conditioning

A/C refrigerant system (R-134a), safety measures

A/C refrigerant system, general repair guidelines

Commercial designation

Color

Airborne properties

Solubility of refrigerant oil

Effects on the environment

Toxicity

Temperature/pressure relationship

Effects on plastics

Effects on metal

Critical temperature/critical pressure

Water solubility

Flammability

Refrigerant containers

Leak detection

A/C refrigerant oil (PAG), properties

Refrigerant system with restrictor and accumulator

A/C compressor

A/C condenser

Evaporator

Accumulator

Restrictor

O-rings

Hoses and lines

A/C refrigerant system (R-134a), valves and switches

Pressure relief valve

Function

A/C refrigerant high pressure switches -F23- and -F118

Function of -F23

Function of -F118

Valve connections for pressure switches

Connections for quick coupling adapter on refrigerant circuit

High pressure service connection with Schrader valve

A/C refrigerant system (R-134a), pressure & temperature relationships

Refrigerant circuit with restrictor and accumulator

Contact corrosion!

A/C system refrigerant system, servicing

Switch -F23

Switch -F118

Removing and installing

A/C pressure switch -F129-, functions

Switching pressures (in bar)

Testing

O-rings for refrigerant system

A/C compressor from mounting bracket, removing and installing

Nippondenso compressor

Removing and installing clutch plate bolt

Pulling off clutch disc

Installing magnetic coil

Checking and adjusting gap

Automatic Climate Control components in engine compartment, servicing

Sensor for air quality -G238-, function

Test requirements

Preparation

Sensor for air quality -G238-, removing and installing

Air flow flap motor -V71-, removing and installing

Recirculation flap motor -V113-, removing and installing

Control module for fresh air blower -J126-, removing and installing

Pump valve unit, removing and installing

Pump valve unit, replacing

Dust and pollen filters, removing and installing

Automatic Climate Control components in passenger compartment, servicing

A/C control head -E87-, removing and installing

Changes to model year 2000 vehicles

For A/C control head with part numbers beginning with Index "M"

Checking

Heater cores, removing and installing

Special tools and equipment

Passenger-side heater core, removing and installing

Version "1" heater core, removing

Version "2" heater core, removing

Version "1" heater core, installing

Cleaning

Version "2" heater core, installing

Driver-side heater core, removing and installing

Flap and vent motors, servicing

Left center vent motor -V110- and right center vent motor -V111-, removing and installing

Center vent adjusting motor -V102-, removing and installing

Defroster flap motor -V107-, removing and installing

Left footwell flap motor -V108- and rear footwell vent motor -V112-, removing and installing

Temperature regulator flap motor -V68- and right footwell flap motor -V109-, removing and installing

Instrument panel interior temperature sensor -G56-, removing and installing

Center air outlet in instrument panel, removing and installing

Making special tool

Side window air outlet in right (left) of instrument panel, removing and installing

Climate Control Components in passenger compartment, updates from m.y. 2000

Air distribution, schematic diagram

Preparatory work

Automatic Climate Control System heating performance and operation of pump valve unit, testing

A/C refrigerant system (R-134a), components

A/C condenser, removing and installing

Restrictor, removing and installing

A/C refrigerant lines from Nippondenso compressor, removing and installing

A/C compressor, removing and installing

A/C evaporator, removing and installing

Removing

Removing version "2" evaporator

Installing

Air conditioner housing, removing and installing

Air conditioner housing, disassembling and assembling

Screen, fresh air blower, evaporator and covers in plenum, removing and installing

Disassembling And Assembling Cover With Recirculating Air Flap

Disassembling And Assembling Intake Shaft

Air conditioner housing (lower) and air distribution housing, disassembling and assembling

Air distribution housing, disassembling and assembling

A/C refrigerant system (R-134a), leak testing

A/C refrigerant system (R-134a), testing with pressure gauges

Measuring pressure and temperature in a "switched-on" refrigerant system

Measuring pressure and temperature in a closed container or "switched-off" refrigerant system

A/C refrigerant system (R-134a), checking pressures

Preparation work

If A/C refrigerant system base pressure is less than specified on chart, system is low on refrigerant

If A/C refrigerant system pressure corresponds to or is higher than base pressure specified on chart

Pressure in refrigerant circuit corresponds to chart or is higher

Refrigerant R-134a

Refrigerant (PAG) oil

A/C refrigerant system (R-134a), discharging

Discharging

A/C refrigerant system (R-134a), evacuating & recharging

Evacuating & recharging

A/C refrigerant system (R-134a), flushing with compressed air and nitrogen

A/C does not cool (cooling has stopped completely)

Insufficient cooling during all driving or engine speed (RPM)

A/C compressor noisy

A/C compressor noisy immediately after switching A/C ON and/or when driving around corners or braking "refrigerant shock" -refrigerant system Overcharged

With an otherwise properly operating A/C system, water sprays out of instrument panel vents

A/C refrigerant system (R-134a), replacing components

All sections

Pump valve unit, replacing Audi A8 D2

Air Conditioning 1 illustration

Pump valve unit, replacing

WARNING

The cooling system is pressurized when the engine is warm. Wear gloves and other appropriate protection, and slowly and carefully release system pressure, if necessary, before performing repairs.

Remove pump valve unit. See «PUMP VALVE UNIT, REMOVING AND INSTALLING»(/audi/a8/d2-1994-1999/remont/automatic-hvac-system/#air-conditioning__pump-valve-unit-removing-and-installing).
Remove screws -A-. (Scheme 65)
Remove bracket -B-.
Remove coolant hoses (hoses -C- to heater core on passenger side, hoses -D- to heater core on passenger side, hoses -D- to heather core on driver side).

Scheme 50

Scheme 50

Scheme 50

Note. Replace O-rings -E-. Insert rubber mounts -F- in the pump valve unit and in the bracket -G- as shown in the figure.