Removing and installing brake caliper piston, floating caliper disc brake 2FNR — VW

Removing and installing brake caliper piston, floating caliper disc brake 2FNR
Special tools and workshop equipment required
Removal wedge
3409
Piston resetting appliance
T10145
Assembly tool for protective caps
T10146/5
Removing
Note
Removal and installation of brake pistons are described for one of the two brake pistons only. Proceed in the same way when removing and installing the second brake piston.
Front brake caliper is removed
Position
piston resetting appliance
T10145
1
on one of the two brake pistons.
Place a piece of wood in brake caliper shaft in front of other brake piston to prevent it from being damaged when pressing out.
Press out brake piston from brake caliper housing using compressed air.
Lever off protective cap from brake caliper using
removal wedge
3409
1
.
Remove
piston resetting appliance
T10145
1
from brake caliper.
Remove seal from brake caliper housing using
removal wedge
3409
2
.
Note
When removing, ensure that the surface of the brake piston is not damaged.
Installing
Installation is performed in reverse sequence; note the following:
Note
The surfaces of the piston and oil seals must be cleaned only with methylated spirits and then dried.
Apply thin coat of assembly paste to brake piston and seal before installing.
Insert seal into groove of brake caliper housing.
Press protective cap into brake caliper housing using
piston resetting appliance
T10145
2
and
assembly tool for protective caps
T10146/5
1
.
Push protective cap onto brake caliper housing so that it comes into contact all around housing
arrow
.
Check seat of protective cap:
Make sure that protective cap
1
can no longer be pulled off brake caliper housing
2
by hand.
Apply thin coat of assembly paste to brake piston and seal before installing.
Position
piston resetting appliance
T10145
3
on second brake piston and preload tool.
Press brake piston lightly onto protective cap e.g. using a commercially available extension
1
. When doing this, do not cant piston (keep straight) to prevent damage to protective cap.
Inflate protective cap with compressed air (maximum 3 bar)
2
. The protective cap will then locate around the brake piston.
Slowly press brake piston into brake caliper housing by hand.
Note
The inner sealing lip on the protective cap
1
will then slip into the brake piston groove
2
.
Install brake caliper
Chapter
.
Specified torques
Chapter
“
Assembly overview - front brake caliper, floating caliper disc brake 2FNR
”