Lexus SC300 / Lexus SC400. Manual — part 10

SERVICE SPECIFICATIONS

SERVICE DATA

Idle speed

Magnetic clutch no engaged

Approx. 700 rpm

Magnetic clutch engaged

Approx. 700 rpm

Magnetic clutch clearance

0.5

±

0.15 mm

0.020

±

0.006 in.

TORQUE SPECIFICATIONS

Part tightened

N

⋅

m

kgf

⋅

cm

ft

⋅

lbf

Suction hose X Compressor

25

250

18

Discharge hose X Compressor

25

250

18

Compressor X Engine

Bolt

49

500

36

Nut

29

300

22

Liquid tube X Receiver

10

100

7

Liquid tube X Condenser

10

100

7

Discharge tube X Condenser

10

100

7

Expansion valve X Evaporator

5.4

55

48 in.

⋅

lbf

Suction tube X A/C Unit

10

100

7

Liquid tube X A/C Unit

10

100

7

Equalizer tube X EPR

25

250

18

Pressure switch X Liquid tube

10

100

7

–

AIR CONDITIONING SYSTEM

Service Specifications

AC–141

Lexus Supports ASE Certification

Page 1 of 4

Title:

R-12 AIR CONDITIONER SYSTEM

RETROFIT

Models:

’90–’93 ES 250/300, SC 400/300, LS 400

Technical Service

Information Bulletin

April 3, 1998

A

C

001–98

The following information should be used for guidance when retrofitting vehicle air
conditioning systems from R–12 to R134a refrigerant.

S

1990–1992 model year LS 400, 1990–1991 model year ES 250, 1992–1993 model
year ES 300, 1992–1993 model year SC 300, 1992–1993 model year SC 400

All parts required for retrofit are available through the normal parts system:

IDENTIFICATION

REQUIRED PARTS & MATERIALS

MODEL

COMPRESSOR

RETROFIT SET

RECEIVER

ND OIL 8

CHARGE

LS 400

10PA20

88471–16050

170 cc

1000 g

ES 250

10PA17V

88840–33020 (1)

l

88471–12040

100 cc

650 g

ES 300

plus

90099–14044 (2)

SC 300

10PA17

90099–14044 (2)
90099–14045 (1)

88471–16050

150 cc

900 g

SC400

90099 14045 (1)

g

NOTE:

Retrofit Set 88840–33020 includes:

88374–33010

Low pressure side service fitting adaptor (7/16–20 UNF)

88374–33020

High pressure side service fitting adaptor (3/8–20 UNF)

88723–20040

R134a “USE ONLY” label (ND Oil 8 for 10P, 10PA compressor)

88723–33050

Retrofit Caution Label

90099–14046

Piping O–rings for discharge hose (quantity 2)

Required for all models (not included in set):

90099–14044

Receiver O–rings (quantity 2)

08885–09107

ND–Oil 8

Also available as needed:

88374–33040

L–shaped low pressure side service fitting adaptor

88374–33050

L–shaped high pressure side service fitting adaptor

OP CODE

NWC

DESCRIPTION

TIME

OPN

T1

T2

Not Applicable to Warranty

Affected Vehicles

page 1

. . . . . . . . . .

Service Precautions

page 3

. . . . . . . .

Retrofit Kit Parts

page 1

. . . . . . . . . . .

Required Parts

page 2

. . . . . . . . . . . . .

Required Tools & Materials

page 2

. . .

Retrofitting Overview

page 2

. . . . . . . . .

Repair Procedures

page 3

. . . . . . . . . . .

Warranty Information

page 1

. . . . . . . . .

HEA

TING

& AIR CONDITIONING

Introduction

Affected
Vehicles

Parts

Information

Warranty

Information

Table of

Contents

R–12 AIR CONDITIONER SYSTEM RETROFIT – AC001–98

April 3, 1998

Page 2 of 4

A. Required Equipment:

1. R–12 recovery/recycling/recharging equipment
2. R134a recovery/recycling/recharging equipment
3. Measuring cylinder (for compressor oil)
4. Valve core remover for service valves
5. Air conditioner service tool set
6. Torque Wrench Set, P/N 00002–50284–01, includes the following*:

S

14 mm

00002–51410–01

S

17 mm

00002–51710–01

S

22 mm

00002–52216–01

S

27 mm

00002–52724–01

B. Required Parts & Materials: **

1. R134a Refrigerant
2. Service Fitting Adaptors
3. Caution Labels
4. ND–OIL 8 compressor oil (PAG type oil)
5. Receiver
6. O–Rings for compressor, line & hose connections ***
7. Loctite 262 or equivalent

*

required size dependent upon model.

**

see parts information section of this bulletin on page 1.

***

it is not necessary to replace any O–rings on ES 300, SC 300 and SC 400 models.

A. Refrigerant and Oil Charges

S

Oil and refrigerant charge amounts are different after the R–12 system has been
retrofitted to R134a. Refrigerant charge amounts are less, while oil charge
amounts are greater, compared to R–12 system requirements. Refer to the

ND

OIL

8

and

CHARGE

columns in “Parts Information” table on page 1 for proper amounts.

B. System Performance

S

A slight decrease in system performance may be noticed on some vehicles under
certain operating conditions.

C. Refrigerant Pressures

S

R134a high side pressures are greater than that of R–12 above ambient
temperatures of 68

°

F.

D. Flushing Requirements

S

There is no need to remove or flush R–12 mineral oil from the system. Simply
charge the system with the specified amount of ND–Oil 8 to provide proper
lubrication.

E. Use of Sight Glass

S

Mineral based R–12 oil remains and circulates in the A/C system and does not
dissolve in R134a refrigerant. This results in a cloudy appearance at the sight
glass making it impossible to judge the refrigerant charge amount by using the
sight glass method. To prevent misdiagnosis on retrofit vehicles, apply black
paint to the sight glass on block–joint (FF) type Receivers. Union–nut joint (BAG)
type retrofit Receivers are manufactured without a sight glass.

Required

Tools &

Materials

Retrofitting

Overview

R–12 AIR CONDITIONER SYSTEM RETROFIT – AC001–98

April 3, 1998

Page 3 of 4

A. Refrigerant handling

1. Do not handle refrigerant in an enclosed area or near an open flame.
2. Always wear eye protection.
3. Avoid getting liquid refrigerant in your eyes or on your skin.
4. Never heat a container with an open flame.
5. Keep containers below 104

°

F.

6. When heating a refrigerant can with water, keep the valve above water.
7. Never reuse empty service cans.

B. Replacing parts

1. Plug off any open connections to prevent the entry of moisture and dust.
2. Do not remove plugs from Receiver ports until it is ready for installation.

C. Tightening connecting parts

1. Apply a few drops of ND–Oil 8 compressor oil to O–ring fittings before tightening.
2. Avoid twisting refrigerant piping when installing R134a service fitting adapters.
3. Tighten all fittings to specified torque.

D. Recharging with A/C “on”

1. Never open the high side valve with the engine running.
2. Never run the A/C system when low on refrigerant as compressor damage may

occur.

3. Never charge the system with liquid refrigerant with the engine running.
4. Be careful not to overcharge the system.

NOTE:

Oil removed during R–12 evacuation should not be used with an R134a System.

A. Vehicle Inspection:

S

Ensure the integrity of the A/C system before proceeding with retrofit.

B. Recover R–12 using R–12 recovery/recycling/recharging equipment:

S

Follow Lexus recommended procedure.

C. Install R134a service fitting adapters:

1. Remove valve cores from R–12 service fittings and discard.
2. Clean external threads of the R–12 service fittings.
3. Apply adhesive to threads (Loctite 262 or equivalent), screw on R134a adapter

fittings, and tighten to 13 ft–lb.

NOTE:

Vehicles with more than 2 service fittings will require the installation of additional
adaptors. All service fittings must have R134a adaptors installed.

D. Replace piping and hose O–rings:

1. Disconnect discharge hose from compressor.
2. Remove and discard old O–rings.
3. Lubricate with ND–Oil 8 and install new O–rings.
4. Disconnect discharge hose from condenser.
5. Lubricate and install retrofit O–rings with ND–Oil 8.
6. Reconnect hoses and torque to specification. (Specifications can be found in

applicable manuals/guides.)

Service

Precautions

Repair

Procedure