JHCBC AUTO A/C PERFORMANCE TESTING CHAPTER 3 Page 50-53

JHCBC AUTO PREPARATION Develop a consistent routine. Use Common Sense Approach Consult Service Manuals Cleanliness Safety Windows Down

JHCBC AUTO VISUAL INSPECTION Inspect under hood for SIGNS OF LEAKAGE/HOSE CONDITION Inspect CONDENSER for signs of damage Inspect COMPRESSOR BELT condition Inspect COOLING SYSTEM condition Inspect A/C Controls Function

JHCBC AUTO STABILIZE SYSTEM Make sure Manifold Gauge set valves are shut before hooking up to system Connect to the system Start Engine and Run rpm Let Engine get to full operation temp Turn on A/C and set blower to high and set A/C system to max A/C Put thermometer in A/C duct inside car.

JHCBC AUTO Manifold Gauge Set A Manifold Gauge Set 3 Pressure Hoses Low Side (blue hose) Compound Gauge - vacuum to approx. 250 PSI High Side (red hose) Gauge - 0 to approx PSI Two separate Hand Valves Some Gauges can be calibrated

JHCBC AUTO Manifold Gauge Set Operation Pressure Check of System - both valves closed Charging with Refrigerant - Low side open Evacuation - Both valves open Page 5L

JHCBC AUTO GAUGE PRESSURE CHECK Low side average: 20 to 30 PSI High side average: 160 to 220 PSI High side “rule of thumb”: Add 100 PSI to ambient temperature example: It’s 80 degrees outside, add 100 PSI. approximate high side pressure should be 180 PSI Discharge temperature should be within specified range for system. (35 to 50 degree)

JHCBC AUTO “HAND FEEL CHECK” RULE OF THUMB: –All high side hoses and components should be warm to touch –All low side hoses and components should be cool to the touch Note condition of TXV or FOT –Is is frosted on inlet side = bad valve or orifice or moisture in system

JHCBC AUTO QUICK “FEEL” CHECK If ambient temp above 70 degrees F Engine warm and at idle Max A/C and High Blower feel evaporator inlet pipe and accumulator –Both same temp and cooler than ambient - OK –inlet pipe cooler than accumulator - Low charge –Inlet pipe warmer than evap outlet - overcharge

JHCBC AUTO Hand Tools You Will Use Thermometer Leak Detector Vacuum Pump Snap Ring Pliers Seal Installers/Removers Safety Glasses Can Taps and Hose Adapters (pg.. 49L) Shut Off Valve Service Hose (pg. 46L)

JHCBC AUTO TEST CONTROL DEVICES Refer to Service Manual Relative Humidity Pg. 8C and 53L Make sure if FOT system that clutch is cycling (norm temp) Can test Expansion Valve if accessible Condenser Fan Operation

JHCBC AUTO

JHCBC AUTO Be Cool Out There!!!