Volkswagen Golf/Jetta 2 manual

Brake calipers - removal, overhaul and refitting
Braking system / Brake calipers - removal, overhaul and refitting


Warning: Brake hydraulic fluid may be under considerable pressure in a pipeline, take care not to allow hydraulic fluid to spray into the face or eyes when loosening a connection.

Warning: Never refit old seals when reassembling brake
system components
Front calipers
1 Jack up the front of the vehicle and support it on axle stands (see Jacking and vehicle support). Apply the handbrake and remove both front wheels. Unbolt and remove the caliper from the wheel bearing housing.

2 If available, fit a hose clamp to the caliper flexible brake hose. Alternatively, remove the fluid reservoir filler cap and tighten it down onto a piece of polythene sheet in order to reduce any loss of hydraulic fluid.

3 Loosen and detach the brake hose union at the caliper, allowing for a certain amount of fluid spillage. Plug the hose union to prevent ingress of dirt.

4 Clean the external surfaces of the caliper with paraffin and wipe dry. Plug the fluid inlet during this operation.

5 Prise free and remove the dust seal from the piston (see illustration).

3.5 Removing the dust seal
3.5 Removing the dust seal

6 Using air pressure from a foot pump in the fluid inlet, blow the piston from the cylinder whilst taking care not to drop the piston. Prise the sealing ring from the cylinder bore. Take care not to scratch the cylinder bore.

7 Clean all components with methylated spirit and allow to dry. Inspect the surfaces of the piston, cylinder and frames for wear, damage and corrosion. If necessary, renew the caliper.

If all components are in good condition then obtain a repair kit of seals.

8 Dip the new sealing ring in brake fluid and locate it in the cylinder bore groove using the fingers only to manipulate it.

9 Manipulate the new dust cap into position on the piston, engaging the inner seal lip in the piston groove. Use a suitable screwdriver to ease it into position whilst taking care not to damage the seal or scratch the piston (see illustration).

3.9 Dust seal location on caliper piston
3.9 Dust seal location on caliper piston

10 Smear the piston with brake fluid and press it into position in the caliper bore.

11 Check that the brake hose union is clean, then unplug it and refit it to the caliper. Do not fully tighten it at this stage.

12 Refit the caliper to the wheel bearing housing.

13 Tighten the brake hose union so that the hose is not twisted or in a position where it will chafe against surrounding components.

14 Remove the hose clamp or polythene sheet from the reservoir. Top-up the brake fluid and bleed the brakes.

Rear calipers
15 Chock the front wheels, jack up the rear of the vehicle and support it on axle stands (see Jacking and vehicle support). Remove both rear wheels and remove the brake pads.

16 If available, fit a hose clamp to the caliper flexible brake hose. Alternatively, remove the fluid reservoir filler cap and tighten it down onto a piece of polythene sheet in order to reduce any loss of hydraulic fluid.

17 Loosen and detach the brake hose union at the caliper. Allow for a certain amount of fluid spillage and plug the hose union to prevent the ingress of dirt.

18 Unscrew and remove the lower caliper retaining bolt (where applicable) and remove the caliper (see illustration). This self-locking bolt must be removed.

3.18 Rear brake caliper components
3.18 Rear brake caliper components

19 Clean the external surfaces of the caliper with paraffin and wipe dry. Plug the fluid inlet during this operation.

20 Secure the caliper in a soft-jawed vice.

Using an Allen key or angled circlip pliers, unscrew the piston from the cylinder (see illustration).

3.20 Removing the piston from the cylinder
3.20 Removing the piston from the cylinder

21 Using a screwdriver, carefully ease out the O-ring from the cylinder bore (see illustration).

3.21 Removing the O-ring seal from the cylinder
3.21 Removing the O-ring seal from the cylinder

22 Prise free the protective cap from the piston.

23 Clean the components with methylated spirit and allow to dry. Inspect the surfaces of the piston, cylinder and frames for wear, damage and corrosion. If necessary, renew the caliper. If the components are in good condition then obtain a repair kit of seals.

24 Dip the new O-ring in brake fluid and locate it in the cylinder bore groove using the fingers only to manipulate it.

25 Smear the piston with brake fluid then manipulate the new protective cap into position on the inner end of the piston with the outer seal lip on the piston (see illustration).

3.25 Protective cap on piston
3.25 Protective cap on piston

26 Hold the piston at the entrance to the cylinder housing and carefully manipulate the inner seal lip of the protective cap into the groove in the cylinder bore using a suitable screwdriver (see illustration).

3.26 Manipulating inner seal lip of protective cap into cylinder bore groove
3.26 Manipulating inner seal lip of protective cap into cylinder bore groove

27 Locate the Allen key or angled circlip pliers into the piston and pressing firmly down, screw the piston fully home into the cylinder so that the outer seal lip of the protective cap springs into the location groove in the piston (see illustration).

3.27 Screwing piston downwards through protective cap and into position in
3.27 Screwing piston downwards through protective cap and into position in cylinder

28 Caliper reassembly is now complete but before refitting it to the vehicle, it must be topped up with brake fluid and bled. To do this, unscrew the bleeder valve then support the caliper in the upright position. Connect a suitable union, hose and fluid supply applicator to the bleed valve connection in the caliper. Apply fluid and top-up the caliper until fluid is seen to emerge from the brake hose connection without air bubbles. Tighten the bleed valve and plug the brake hose connection aperture (see illustration).

3.28 Bleeding rear brake caliper unit prior to refitting
3.28 Bleeding rear brake caliper unit prior to refitting

Arrows indicate brake bleed valve and brake hose connection point

29 The caliper can now be refitted to the vehicle.


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