Owner's Manual

Tru Pointe
Instruction 0019-9328
10
False Refrigerant Indication
False refrigerant indications are usually caused by abnormal changes in
sensor temperature. These temperature changes are typically due to a sud-
denchangeinairowpastthesensor,orthesensorbeingheatedorcooled
by an outside source. To avoid false refrigerant indications, DO NOT . . .
•allowtheprobetiptobecomecloggedwithdirt,
•allowtheprobetosuckinhotgases.
SAE Leak Detection Tips
ThefollowingwasderivedfromSAESurfaceVehicleStandardJ1628,
Technician Procedure for Using Electronic Refrigerant Leak Detectors for
Service of Mobile Air-Conditioning Systems:
•Theelectronicleakdetectorshallbeoperatedinaccordancewiththe
equipment manufacturer’s operating instructions.
•Leaktestwiththeenginenotinoperation.
•Theairconditioningsystemshallbechargedwithsufcientrefrigerant
tohaveagaugepressureofatleast340kPa(49psi)whennotinopera-
tion.Attemperaturesbelow15°C(59°F),leaksmaynotbemeasurable,
since this pressure may not be reached.
•Takecarenottocontaminatethedetectorprobetipifthepartbeing
tested is contaminated. If the part is particularly dirty, it should be
wiped off with a dry shop towel or blown off with shop air. No cleaners
or solvents shall be used, since many electronic detectors are sensitive to
their ingredients.
•Visuallytracetheentirerefrigerantsystem,andlookforsignsofair-
conditioning lubricant leakage, damage, and corrosion on all lines, hos-
es, and components. Each questionable area shall be carefully checked
withthedetectorprobe,aswellasallttings,hose-to-linecouplings,
refrigerantcontrols,serviceportswithcapsinplace,brazedorwelded
areas, and areas around attachment points and hold-downs on lines and
components.
Operation