A/C - System Revisions for R-12/R134 Retrofit

HEATING & AIR CONDITIONING
AC93-001
FEBRUARY 26, 1993
LS 400 & ES 300

Title:
HFC134a INFORMATION





Because of the significant chemical differences between R-12 and HFC134a refrigerant, many A/C system components have been revised.

Under no circumstances should the refrigerant, O-rings or oil be interchanged between R12 and HFC134a A/C systems.

O-RINGS:

HFC134a system O-rings are manufactured from an entirely new material. In addition, sealing surfaces have been redesigned thereby requiring the HFC134a O-rings to be slightly thicker than the equivalent R-12 O-ring:

^ 0.4 mm thicker for liquid tubes.
^ 0.6 mm thicker for discharge and suction tubes & hoses.

OIL:

HFC134a systems utilize polyalkylene glycol (PAG), a synthetic lubricant in place of the mineral oil used in R-12 systems, which is identified as ND-Oil 8. PAG type lubricants have a significantly higher moisture absorption rate than the mineral oils currently used in Lexus R-12 systems.

In general, PAG oil can be stored in a cool, dry place for up to two years if it has not received excessive exposure to the atmosphere. It is necessary to properly seal the ND-Oil 8 container immediately after each use. If ND-Oil 8 is left exposed to the atmosphere for more than 24 hours, it MUST be discarded. Proper disposal procedure for any oil should always be used.

Take care not to spill or pour any ND-Oil 8 onto a vehicle's body or any painted surface. If this should occur, wipe the surface immediately with a soft cloth.

Currently, the oil is available in 2 sizes:

SIZE PART NUMBER
40cc 08885-09109
250cc 08885-09107