Chevrolet Cobalt Service & Repair Manual: Cooling System Leak Test
| A visual inspection must always
be performed to confirm the presence of aftermarket components, potential
collision damage, or areas of concern. |
| Always clean all external cooling
system components, hoses and lines before starting the inspection. The origination
of an external leak can be narrowed down considerably during cleaning. |
| Caution: To avoid danger of
being burned, do not remove radiator or reservoir cap while engine and radiator
are still hot, as fluid and steam can be blown out under pressure. |
| Before using a radiator pressure
tester, wet relief valve and pressure valve with engine coolant or water. |
| When performing pressure tests,
keep tester at an angle of over 30° above horizontal. |
| Refer to published specifications
to determine proper cooling system operating pressures. |
| 1. |
Remove radiator or reservoir cap. |
| 2. |
Fill radiator and overflow to proper
level with coolant. |
| 3. |
Inspect overflow tube and overflow
bottle for dents, kinks, or internal obstructions. |
| 4. |
Wipe out inside of filler neck. Inspect
lower inside sealing seat of filler neck for nicks, dirt and solder
bumps. |
| 5. |
Inspect cams on outside of filler neck.
If cams are bent down or up, seating of pressure cap valve and tester
seal will be affected. If cams are damaged, have filler neck replaced
by a reputable radiator repair service facility. |
| 6. |
Attach a radiator pressure tester and
rotate tester head until locking ears contact stops on radiator. |
| 7. |
Operate pump until indicator on gauge
reaches just beyond color band for recommended pressure for vehicle,
Fig. 1. |
| 8. |
If pressure drops, inspect hoses, radiator
or water pump for leaks. If no external leaks are found and pressure
drops, inspect heater core, cylinder block and head. |
| 9. |
Once leak has been detected repair
system as required. |
|
Fig. 1 Cooling system pressure chart
Warning: To avoid being burned,
do not remove the radiator cap or surge tank cap while the engine is hot.
The cooling system will release scalding fluid and steam under pressure
if ...
A visual inspection must always
be performed to confirm the presence of aftermarket components, potential
collision damage, or areas of concern.
Always clean all external c ...
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Chevrolet Cobalt Owners Manual
Chevrolet Cobalt Service Manual
Coolant Drain, Flush & Refill
Cooling System Leak, Inspection