Porsche 928 - WORKSHOP MANUAL 1977 Workshop Manual page 55

928
Front Wheel Suspension
40
Testing Dampers
Dampers can only be tested properly
on a testing machine. Dampers which
no longer perform adequately cannot
be identified by visual inspection
or function testing, which will,
however, identify completely
defective units.
Note:
Differences between dampers, P.
40 - 51
Boge Pressureless
Damper
With damper in installation posi-
tion, extend and compress by hand.
The damper must move smoothly and
with uniform resistance throughout
its travel. The extension and com-
pression stage damping must be
clearly perceptible up to the limit
positions. Dampers which have been
stored for an extended period
should be operated several times in
their installation oosition. Renew
leaking dampers
Boge Gas-press
Dampers
ure
With damper in installation
position, extend and compress by
hand. The damper must move smoothly
throughout its travel. The
expansion and compression stage
damping must be clearly perceptible
up to the final position.
Because of the gas pressure, resis-
tance increases as the piston rod
moves further into the damper.
Dampers which have been stored for
lengthy periods should be operated
several times in their installation
position.
Renew leaky dampers.
Dampers in which the gas pressure
has diminished (damper does not
return automatically to the
extension-stage stop), but which
bear no indication of oily leaks
and which fulfill all other
requirements can be reused.
Dampers which show traces of oil
loss and which have depressurized
must be renewed.
Bilstein Dampers
WornBilstein Dampers
can be identified with ease.
Measure distance X with damper
fully compressed (i.e. as far as
possible). If distance X exceeds
35 mm (29.5 mm when new), the
damper must be replaced.
Printed in Germany - XIII,
1986
Disassembling and Assembling
40 - 43
Adjustable and Non-Adjustable
Spring Struts