Shock Absorber Leaks

Vehicles with Coil Springs

Shock absorbers are frequently rejected and replaced because of leaks. Examinations on the test stand and on the vehicle have shown that the replacement of a large number of rejected shock absorbers was not justified.

Slight leaking of oil ("sweating") at piston rod seal is no reason to replace a shock absorber. A shock absorber damp with oil is OK under the following circumstances:

NOTE:

Minor oil excretion is an advantage, since the piston rod oil seal gets lubricated, which thus increases service life. This applies to shock absorbers on the front and rear axles.

Oil leakage (shaded in illustration -arrow-) is visible, but dull, matte and possibly dry due to dust.

Fig 1: Identifying Oil Sweating
Courtesy of AUDI OF AMERICA, LLC
One-sided oil or dirt film formation, no dripping.

A shock absorber is not OK under the following conditions:

Fig 2: Identifying Oil Leakage

Courtesy of AUDI OF AMERICA, LLC

Dripping -arrow-, completely coated with oil film.
A wet oil film that runs down the pipe indicates a leaky shock absorber. A replacement is required in this instance.