Saab SONETT III Service Manual page 87

Disassembly
Ease the rubber dust cap back and remove the lock-ring,
using long-nosed pliers. It is now possible to remove the
push-rod and the cupped washer. Removal of the push-
rod reveals the piston and its seal. Remove the complete
piston assembly. The assembly can be disassembled by
lifting the retainer spring leaf over the tongued end of
the piston. Carefully take the piston seal off the piston
and remove the end seal.
Push down the piston-return spring, thus enabling the
valve spindle to slide through the key-shaped hole in the
retainer so that the spring lets go. Remove the valve
spacer, taking care not to damage the elastic washer lo-
cated under the valve head. Remove the seal from the
valve head.
Examine the cylinder bore and if it not scored or distor-
ted, and feels smooth to the touch, new seals may safely
be fitted. If, on the other hand, the slightest doubt is
entertained about the condition of the bore, a new cyl-
inder should be fitted.
If the old seals are loose on the piston and too big, con-
tamination by mineral oil may be suspected. This is the
commonest cause of cylinder trouble, and of ten sufficient
pains are not taken to prevent it. Seals of natural rubber
are highly susceptible, and even minute quantities of oil
can gradually cause considerable swelling. If the slightest
trouble in this respect is suspected, fit new seals through-
out the system and flush the system clean with pure brake
fluid.
MASTER CYLINDER, DISASSEMBLED
1. Cylinder housing 8. Spring retainer
2. Hose 9. Seal
3. Seal 10. Piston
4. Rod 11. Rubber dust cap
5. Elastic washer
12. Push-rod with cupped washer
6. Valve spacer
13. Lock ring
7. Spring 14. Clutch pedal
412-3
SAAB
June 1970