1979 Ford FiestaFACTORY OEM SERVICE PROCEDURE

Service Specifications

AMBIENT TEMPERATURE-PRESSURE

Ambient Temperature High Side Pressure (PSI)
60 95-115
65 105-125
70 115-135
75 130-150
80 150-170
85 165-185
90 175-195
95 185-205
100 210-230
105 230-250
110 250-270
115 265-285
120 280-310
(1) All temperatures given in Fahrenheit.
(2) Ambient temperature measured 2-6" in front of condenser, or same as room temperature.
Normal System Operating Pressures(1)

Application Low Side Gouge (Evap. Suction) High Side Gauge (Discharge)
American Motors
  1979 Therm. Switch 21 165-225
Chrysler
  1979 (EPR Valve) 22-30 140-240
  1979 (Therm. Switch) 15-30 140-240
Ford Motor Co.
  1979 27.5-29.5 175-185
General Motors
  1979 24-30 105-175
(1) Pressure readings are for system in good operating condition, at sea level and ambient temperature of 80°F.
EVAPORATOR TEMPERATURE-PRESSURE

Evap. Temp. Low Side Pressure (PSI)
2 10
6 12
10 14
14 16
18 18
20 20
22 22
24 24
27 26
29 28
32 30
36 32
42 40
48 45
53 50
58 55
62 60
66 65
70 70
(1) All temperatures given in Fahrenheit.
COMPRESSOR BELT TENSION

  (1)Tension (Lbs.)
Application New Belt Used Belt
American Motors 125-155 90-115
Chrysler Corp. 120 70
Ford Motor Co. 140 110
General Motors
  Buick 130 90
  Cadillac
    Exc. Seville 170 120
    Seville 110-140 60-120
  Chevrolet
    Exc. Chevette 135-145 90-100
    Chevette 125-150
  Oldsmobile
    5/16" Belt 80 50
    3/8" Belt 150 70
    15/32" Belt 165 90
  Pontiac
    4-Cyl. Models 120-130 70-80
    V6 & V8 Models 135-145 90-100
(1) Using standard strand tension gauge
O.E.M. REFRIGERANT CAPACITIES

Application Capacity (lbs.)
American Motors
  AMX, Concord & Spirit 2
  Pacer 2 1/8
Chrysler Corp.
  Horizon & Omni 2 1/8
  All Other Models 2 5/8
Ford Motor Co.
  Bobcat & Pinto 2 1/4
  Capri, Fairmont, Mustang & Zephyr 3 1/2
  Granada, Monarch & Versailles 4
  All Other Models 4 1/4
General Motors
  Buick
    Skyhawk 2 1/2
    Skylark 3 1/2
    All Others 3 3/4
  Cadillac
    Seville 3 1/2
    All Other Models 3 3/4
  Chevrolet
    Camaro 3 1/4
    Chevette 2 1/4
    Corvette 3
    Monza
      "S" Hatchback & Station Wagon 3
      All Other Models 3 1/2
    Nova 3 1/2
    All Other Models 3 3/4
  Oldsmobile
    Starfire
      A-6 Compressor 3
      R-4 Compressor 3 1/2
    Omega 3 1/2
    All Others 3 3/4
Pontiac
  Bonneville & Catalina 3 3/4
  Firebird 3 1/4
  Sunbird 2 1/2
  All Other Models 3 1/2
COMPRESSOR OIL CHARGE

Compressor Capacity
Chrysler
  2 Cyl. (1)10-20 oz.
  6 Cyl. 9-10 oz.
Frigidaire
  4 Cyl. 5.5-6.5 oz.
  6 Cyl. 10-5 oz.
Sankyo 5 Cyl. 8 oz.
Tecumseh 2 Cyl. 11 oz.
York 2 Cyl. 10 oz.
(1) Use dip stick method for final compressor oil check.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.