Preparation For Testing

Attach Low and High Side gauges to system.
Start engine and warm to operating temperature.
Set system to Cool and blower to High.
Open car doors and hood.
Run at fast idle for 2-3 minutes before check.

Air Conditioning System Performance Check

PERFORM TESTS;	SHOULD BE	IF:
Temperature Check		Temperature Check is:
Switch to Low Blower.
Close Doors.
Check Outlet Air Temperature.	35-45°F	Too warm, check function of control levers, heater water valve, cooling system and gauge readings.
Visual Check		Visual Check Shows:
Compressor	No excess noise; no leaks	Noisy, check belts, oil level, seals, gaskets, bearing, reed valves.
Condenser	Free of obstructions	Blocked, clean off debris, Plugged, flush with R-12 or replace.
Receiver-Drier	Dry; warm to touch	Frosty, check for restriction or moisture saturation. Replace desiccant.
Sight Glass	Clear or few bubbles	Bubbly, foamy or streaky, check reference manual and gauge readings.
High Side Lines	Dry; warm to touch; no leaks	Frosty or very hot, check for restriction condenser malfunction or R-12 overcharge.
Expansion Valve	Dry	Frosty, check for moisture or restriction. Check sensing bulb.
Evaporator	Dry; cold to touch	Freezing or warm, check for expansion valve, thermostatic switch or STV malfunction.
STV	Dry; cool to touch	Frosty or warm, check for valve malfunction. Check gauge readings.
Low Side Lines	Dry; cool to touch; no leaks	Frosty or warm, check for restriction, low R-12 charge, or valve malfunction.
Gauge Readings		Gauge Readings are:
High Side Gauge	See Pressure Chart.	Above or below normal, refer to "Air Conditioning Diagnosis " chart.
Low Side Gauge	See Pressure Chart.	Above or below normal, refer to "Air Conditioning Diagnosis " chart.
NOTE: For diagnosis with gauges, refer to chart on following page.

Fig 1: AMBIENT TEMPERATURE/PRESSURE

Courtesy of NOT AVAILABLE

Fig 2: EVAPORATOR TEMPERATURE/PRESSURE

Courtesy of NOT AVAILABLE

Air Conditioning Diagnosis With Gauges For Systems With Insufficient Or No Cooling

Low Side Gauge

High Side Gauge

Other Symptoms ⁽¹⁾

Diagnosis

NORMAL

No or few bubbles in sight glass.
High side gauge may go high.
Low side gauge does not fluctuate with compressor on/off cycle

Some Air and Moisture in System

NORMAL

Cools okay in morning, but not during hot part of day.
Tiny bubbles in sight glass.
Discharge air warm when low side gauge drops into vacuum.

Excessive Moisture in System

NORMAL

Thermostatic switch system only: Compressor cycles on and off too rapidly.

Defective Thermostatic Switch

NORMAL to HIGH

NORMAL

Cycling clutch systems only: Compressor doesn't turn on soon enough.
Discharge air becomes warm as low side pressure builds.

Misadjusted Thermostatic Switch or Defective Pressure Sensing Switch

LOW

Bubbles in sight glass.
Outlet air slightly cool.

Low R-12 Charge

LOW

Sight glass clear.
Outlet air very warm or same as outside air temp.

Excessively Low R-12 Charge

LOW

Outlet air slightly cool.
Sweating or frost at expansion valve.

Expansion Valve Stuck Closed, Screen Plugged or Sensing Bulb Malfunction

LOW

Outlet air slightly cool.
High side line cool to touch.
Sweating or frost on high side.

Restriction in High Side

LOW

HIGH

Evaporator outlet pipe cold.
Low side goes into vacuum when blower is disconnected.

STV Stuck Open

HIGH

LOW

Evaporator outlet pipe worm.
Outlet air warm.

STV Stuck Closed

HIGH

LOW

Noise from compressor.

Compressor Malfunction (Internal Leak)

HIGH

Outlet air warm.
Liquid line very hot.
Bubbles in sight glass

Condenser Malfunction or R-12 Overcharge

HIGH

Outlet air slightly cool.
Bubbles in sight glass

Large Amount of Air and Moisture in System

HIGH

Outlet air warm.
Evaporator and outlet pipe show sweating and frost.

Expansion Valve Stuck Open

⁽¹⁾	if equipped with a Low Refrigerant Charge Protection System, compressor operation may hove stopped in some cases.

O.E.M. REFRIGERANT CAPACITIES

Application			Capacity (Lbs.)
American Motors			2
Chrysler Corp.
	Aries & Reliant		2 1/8
	Horizon & Omni		2 1/8
	All Other Models		2 1/2
Ford Motor Co.
	Ford & Mercury		3 1/4
	Mark VI & Town Car		3
	All Other Models		2 1/2
General Motors
	Buick
		Electro & LaSabre	3 1/2
		Regal & Riviera	3 1/4
		All Other Models	2 3/4
	Cadillac
		Cimarron	2 3/4
		All Other Models	3 3/4
	Chevrolet
		Camaro & Corvette	3
		Cavalier, Celebrity & Citation	7 3/4
		Caprice & Impala	3 1/2
		Chevette	2 1/4
		All Other Models	3 1/4
	Oldsmobile
		Ciera, Firenza & Omega	2 3/4
		88-98	3 1/2
		All Other Models	3 1/4
	Pontiac
		Bonneville & Grand Prix	3 1/4
		Firebird	3
		6000	2 3/4
		J2000	2 1/2
		T1000	2 1/4

COMPRESSOR BELT TENSION

⁽¹⁾ Tension (Lbs.)

Application

New Belt

Used Belt

American Motors

Regulator Belt

125-155

90-115

Serpentine Belt

180-200

140-160

Chrysler Corp

120

Ford Motor Co.

110-140

110-130

General Motors

Buick

140-160

90-100

Cadillac

4 Cyl. V6 & Diesel

170

200

Chevrolet

140-160

90-100

Oldsmobile

140-160

90-100

Pontiac

140-160

90-100

⁽¹⁾	Using standard strand tension gauge.

COMPONENT OIL REPLACEMENT QUANTITIES

Component

Qantity

Accumulator

⁽¹⁾

Condenser

1 oz.

Evaporator

American Motors Systems

1 oz.

Chrysler Corp. Systems

2 oz.

All Other Systems

3 oz.

Receiver-Drier

1 oz.

⁽¹⁾	Amount drained plus 2 oz. for G.M. models, 1 oz. for all others.

COOLING SYSTEM CAPACITIES

Application					Quantity
AMERICAN MOTORS
		Concord & Spirit			6.5 qts.
		Eagle
				Heater Only	11.0 qts.
				A/C	14.0 qts.
CHRYSLER
		Horizon & Omni			6.0 qts.
		Aries & Reliant			8.7 qts
		Le Baron, Rampage & 400			8.7 qts.
		Cordoba & Mirada
			3.7L 6-Cyl.
				Heater Only	11.5 qts
				A/C	14.5 qts.
		Cordoba, Mirada & Imperial
			5.2L V8
				Heater Only	15.0 qts.
				A/C	17.5 qts.
		Diplomat, Gran Fury & New Yorker
			3.7L 6-Cyl.
				Heater Only	1.5 qts.
				A/C	16.5 qts.
FORD MOTOR CO.
		Escort, EXP Lynx & LN7			8.1 qts.
		Cougar, Fairmont, Granada & Zephyr
			2.3L 4-Cyl.
				Heater Only	8.6 qts.
				A/C	9.4 qts.
			3.3L 6-Cyl		8.5 qts.
			3.8L V6		8.5 qts.
		Capri & Mustang
			2.3L 4-Cyl.
				Heater Only	8.6 qts.
				A/C	9.4 qts.
			3.3L 6-Cyl.		8.4 qts.
			4.2L V8		15.0 qts.
			5.0L V8		13.4 qts.
		Thunderbird & XR7
			3.3L 6-Cyl.		8.5 qts.
			3.8L V6		15.0 qts.
			4.2L V8		15.0 qts.
	Ford & Mercury
		4.2L V8			15.0 qts.
		5.0L V8			13.4 qts.
	Lincoln Continental, Town Car & Mark VI
		3.8L V6			11.1 qts.
		5.0L V8			13.4 qts.
GENERAL MOTORS
	Buick
		Century & Skylark
			2.5L 4-Cyl		9.9 qts.
				H.D.	12.1 qts.
			2.8L V6		11.3 qts.
				H.D.	12.1 qts.
			3.0L V6		14.0 qts.
		Regal
			3.8L V6		13.0 qts.
			3.8L V6 Turbo		13.8 qts.
			4.1L V6		13.1 qts.
			4.3L V6 Diesel		14.7 qts.
			5.7L V8 Diesel		17.3 qts.
		LeSabre & Electra
			3.8L & 4.1L V6		13.1 qts.
			5.0L V8
				Heater Only	15.4 qts.
				A/C	16.2 qts.
			5.7L V8 Diesel		17.9 qts.
		Riviera
			3.8L & 4.1L V6		13.1 qts.
			3.8L V6 Turbo		14.1 qts.
			5.0L V8		16.3 qts.
			5.7L V8 Diesel		18.0 qts.
	Cadillac
		Cimarron			9.6 qts.
		Seville, Eldorado, DeVille & Brougham
			4.1L V6		13.1 qts.
		Seville & Eldorado
			4.1L V8		11.8 qts.
			5.7L V8 Diesel		18.4 qts.
		DeVille & Brougham
			4.1L V8		10.8 qts.
			5.7L V8 Diesel		23.7 qts.
	Chevrolet
		Chevette			9.0 qts.
		Cavalier			9.7 qts.
		Celebrity
			2.5L 4-Cyl.		9.7 qts.
			2.8L V6		11.7 qts.
			2.8L & 4.3L Diesel V6		13.9 qts.
		Citation
			2.5L 4-Cyl.
				Heater Only	9.4 qts.
				A/C	9.8 qts.
			2.8L V6		11.7 qts.
		Camaro
			2.5L 4-Cyl		13.0 qts.
			2.8L V6		12.8 qts.
			5.0L V8
				VIN 7	15.8 qts.
				VIN H	17.0 qts.
		Corvette
			5.7L V8		22.0 qts.
		Impala, Caprice, Malibu, Monte Carlo, El Camino
			3.8L V6
				(229")	15.0 qts.
				(231")	12.0 qts.
			4.3L V6 Diesel		13.4 qts.
			4.4L V6		18.6 qts.
			5.0L V8		16.3 qts.
			5.7L V8		18.3 qts.
	Oldsmobile
		Firenza			9.7 qts.
		Ciera & Omega
			2.5L 4-Cyl		9.8 qts.
				H.D.	12.1 qts.
			2.8L V6		11.8 qts.
				H.D.	12.1 qts.
		Cutlass & Cutlass Cruiser
			3.8L V6		13.0 qts.
			4.3L V6		16.0 qts.
			4.3L V6 Diesel		15.0 qts.
			4.4L V6		18.0 qts.
			5.0L V8		15.2 qts.
			5.7L V8 Diesel		17.5 qts.
		88, 98, Custom Cruiser & Toronado
			3.8L & 4.1L V6		13.0 qts.
			4.3L V6 Diesel		13.4 qts.
			4.3L V6		16.5 qts.
			4.4L V6		15.7 qts.
			5.0L V8		16.2 qts.
			5.7L V8 Diesel		18.2 qts.
	Pontiac
		T1000
			1.6L 4-Cyl		9.0 qts.
			1.9L 4-Cyl. Diesel		9.0 qts.
		J2000			9.7 qts.
		Phoenix & 6000
			2.5L 4-Cyl		9.7 qts.
			2.8L V6
				Heater Only	11.3 qts.
				A/C	11.7 qts.
				H.D.	12.1 qts.
			4.3L V6 Diesel		13.9 qts.
		Firebird
			2.5L 4-Cyl.		13.0 qts.
			2.8L V6		12.8 qts.
			5.0L V8
				VIN 7	15.8 qts.
				VIN H	17.0 qts.
		Bonneville & Grand Prix
			3.8L & 4.1L V6		13.1 qts.
			5.7L V8 Diesel		17.3 qts.