Chevrolet Cobalt Service & Repair Manual: Leak Test
| Before beginning any leak test,
attach a manifold gauge set and note pressure. If little or no pressure
is indicated, a partial charge must be installed. Inspect all connections,
compressor head gasket, oil filler plug and compressor shaft seal for leaks. |
Electronic Leak Detectors
| Current versions of electronic
leak detectors have three settings, one for R-12, one for R-134a and one
for gross. The gross setting is for isolating very large leaks already found
in one of the other two settings. Refer to operating instructions for the
unit being used and observe these general procedures. |
| 1. |
Move detector probe one inch per second
in areas of suspected leaks. |
| 2. |
Position probe below test point, as
refrigerant gas is heavier than air. |
| 3. |
Inspect service access gauge port valve
fittings, particularly when valve caps are missing, as dirt accumulations
can destroy sealing area of valve core when manifold gauge set is
attached. Replace missing valve caps after cleaning valve core area.
Valve caps should only be finger tightened. Using pliers to tighten
valve caps may distort sealing surface of valve. |
| 4. |
Inspect for leaks in manifold gauge
set and hoses, as well as rest of system. |
|
Fluid Leak Detectors
| Apply leak detector solution around
joints to be tested. A cluster of bubbles will form immediately if there
is a leak. A white foam that forms after a short while will indicate an
extremely small leak. In some confined areas such as sections of the evaporator
and condenser, use of an electronic leak detector is recommended. |
Fluorescent Leak Detectors
| The high density black light tool
No. J2848-E, tracer dye injector tool No. J41436 and tracer dye tool No.
J41447, or equivalents, were developed to detect refrigerant leaks on R-134a
systems. Do not use any other tracer dye in these systems. Another type
dye may cause premature compressor failure. Use only a 1/4 ounce
charge of dye, larger amounts may effect system performance. After adding
tracer dye, clean service valves and all affected surfaces of the dye with
GM engine degreaser part No. 1050436, or equivalent, to prevent any false
leak diagnosis. |
1.
Remove expansion tube, if equipped.
2.
Remove air compressor.
3.
Install flush adapter to air compressor
...
Add the recommended refrigerant
oil in the amount listed if you replace any of the parts listed. To avoid
contamination, do not return the oil to the container once dispensed, and
n ...
Chevrolet Cobalt Owners Manual
Chevrolet Cobalt Service Manual
Flushing
Oil Change