Tools Required
Most oil leaks are easily located and repaired by visually finding the leak
and replacing or repairing the necessary parts. On some occasions a fluid leak may
be difficult to locate or repair. The following procedure may help in locating and
repairing most leaks.
Finding The Leak
- Identify the fluid, determine whether it is engine oil, automatic transmission
fluid, power steering fluid, etc.
- At what point is the fluid leaking from? After running the vehicle at
normal operating temperature, park the vehicle over a large sheet of paper. After
a few minutes, you should be able to find the approximate location of the leak by
the drippings on the paper.
- Visually check around the suspected component. Check around all gasket
mating surfaces for leaks. A mirror is useful for finding leaks in areas that are
hard to reach.
Notice: Do not use solvents or degreasers to clean the area. These chemicals can cause
seals to swell and make the leak difficult to locate.
- If the leak still cannot be found, clean and dry the area with a shop towel.
Operate the vehicle for several miles at normal operating temperature and varying
speeds. After operating the vehicle, visually check the suspected component. If you
still cannot locate the leak, try using the powder or black light and dye method.
Powder Method
- Clean the suspected area.
- Apply an aerosol-type powder, such as foot powder, to the suspected area.
- Operate the car under normal operating conditions.
- Visually inspect the suspected component. You should be able to trace
the leak path over the white powder surface to the source.
Black Light and Dye Method
A SA9175NE
and SA9176NE
or equivalent are available for finding leaks.
Refer to the manufacturer's directions when using the kit.
- Pour the specified amount of dye into leaking component.
- Operate the vehicle under normal operating conditions as directed in the
kit.
- Direct the light toward the suspected area. The dye fluid will appear
as a yellow path leading to the source.
Repairing The Leak
Once the leak has been pinpointed and traced back to its source, the cause of
the leak must be determined in order for it to be repaired properly. If a gasket
is replaced, but the sealing flange is bent, the new gasket will not repair the leak.
The bent flange must be repaired also. Before attempting to repair a leak, check
to make sure that the following conditions are correct as they may cause a leak.
Gasket Leaks
Inspect the gaskets for leaks:
• | High fluid level or high oil pressure. |
• | Plugged ventilation filter or valve. |
• | Improperly tightened fasteners or dirty/damaged threads. |
• | Warped flanges or sealing surface. |
• | Scratches, burrs or other damage to the sealing surface. |
• | Damaged or scratched vibration damper retaining bolt/washer. |
• | Damaged or worn gasket. |
Seal Leaks
Inspect the seals for leaks:
• | High fluid level or high oil pressure. |
• | Damaged seal bore, scratched, burred or nicked. |
• | Shaft surface scratched, nicked or damaged, refer to illustration below. |
• | Loose or worn bearing causing excess seal wear. |
Valve Guide O.D. Leaks
Inspect for:
Oil leaking between the outside diameter of the valve guide and the cylinder
head casting. To help identify an oil leak between the outside diameter of the guide
and the cylinder head casting, apply several drops of engine oil dye SA9176NE around
the outside diameter of the valve guide and allow to sit for a minimum of 3 minutes.
Inspect the gaskets for leaks: minutes. Use SA9175NE to identify oil
leak location.
Oil leaking between the outside diameter of the valve guide and the cylinder
head casting can be caused by a damaged cylinder head casting valve guide bore.
If oil is leaking between the outside diameter of the valve guide and the cylinder
head casting, install an oversize valve guide.