Procedures
Thread for the Threaded Brake Caliper Connection, Servicing
• For vehicles with aluminum wheel bearing housing.
• All activities while servicing the thread are performed by hand without any additional tools.
List of Individual Tools for Brake Caliper Repair Set (VAS 6627)
1 Drill template
2 Fitting bolt M12 x 1.5
3 Fitting bolt M14 x 1.5
4.1 Brass sleeve M12 for special drill and seat cutter
4.2 Brass sleeve M12 for thread drill
5.1 Brass sleeve M14 for special drill and seat cutter
5.2 Brass sleeve M14 for thread drill
6 Clamping tool
7 Container for cutting oil
List of Individual Tools for "Thread repair kit M12x1.5" (VAS 6627/8) for the Thread M12x1.5
1. Special drill
2. Seat cutter
3. Thread drill M12x1.5
4. Grooving tool M12x1.5
5. Threaded bushing M12x1.5
List of Individual Tools for "Thread repair kit M14x1.6" (VAS 6627/9) for the Thread M14x1.5
1. Special drill
2. Seat cutter
3. Thread drill M14 x 1.5
4. Grooving tool M14 x 1.5
5. Threaded bushing M14 x 1.5
Instructions
• The following instruction is for the rear brake caliper. There is little room to work here and it can be difficult to reach in this area.
• The thread repair for the front brake caliper is identical.
- Remove the wheel.
• Before pressing brake pads back, draw off brake fluid from reservoir using a bleeder bottle. Otherwise, especially if reservoir has been topped off, fluid will overflow and cause damage.
- Press the brake pads off the brake disc.
- Remove the brake caliper from the wheel bearing housing.
- Remove brake caliper and suspend with wire so that the weight of the caliper does not cause any stress or damage to the brake line.
- Move the parking brake motors into its installed position with the vehicle diagnosis, testing and information system (VAS 5051).
- Remove the brake disc.
- Tighten the drill template - 1 - with the previously mentioned fitting bolt (M12 rear or M14 front) - 2 -.
- Slide - arrow 1 - the brass sleeve - A - from behind on the special drill - B - so that the special drills cutting does not damage the brass sleeve.
- Then insert - arrow 2 - the special drill and brass sleeve in the drill template - C -.
- Install and tighten the grooving tool - 1 - on the special drill- 2 -.
• The special drill from the tool set has the mentioned length (when connected to the drill template) for the exact hole depth.
- Drill, by hand, until the grooving tool - 1 - is touching - arrows A - the brass sleeve- 3 -.
- Loosen the fitting bolt - 2 - slightly and then tip the drill template - 1 - on its side.
- Clamp the seat cutter - 2 - in the grooving tool- 1 - and drill all the way until it stops at the end of the seat cutter (see the following illustration N46-10330).
Stop Depth -A- on the Seat Cutter
- In order to check the depth, first place the seat - A - and then the surrounding threaded bushing - 1 - in the hole.
• The seat of threaded bushing must not be visible after having been placed in the hole.
- Remove the shavings, wear protective glasses.
- Tip the drill template - 1 - back over the hole and tighten it with the fitting bolt- 2 -.
- Now slide- arrow 1 - the brass sleeve - D - from behind off of the thread drill - E -, so that the thread drills cutting does not damage the brass sleeve.
- Put a little cutting oil on the thread drill.
- Insert - arrow 2 - the thread drill and brass sleeve in the drill template - C -.
• Even though in the beginning the brass sleeve is still somewhat outside of the drill template, it is still able to be guided.
- Install and tighten the grooving tool - 1 - on the thread drill- 2 -.
- Cut the thread so deep, until the grooving tool - 1 - is touching - arrows A - the brass sleeve- 3 -.
- Clean the hole, remove shavings and cutting oil, wear protective glasses.
- Turn the threaded bushing - 1 - by hand, on the grooving tool - 2 - until a light resistance can be felt.
The threaded bushing must not be completely tightened on the grooving tool, otherwise the threaded bushing will become deformed prematurely.
- Turn the threaded bushing - 1 - by hand with the grooving tool - 2 - until it is flush with the wheel bearing housing surface - A -.
The grooving tool - 2 - must not twist further in the threaded bushing - 1 - before the threaded bushing- 1 - is flush with the wheel bearing housing surfaces - A -.
The threaded bushing must be completely covered by the wheel bearing housing, otherwise the brake caliper will not fit securely.
- Clamp the clamping tool on the grooving tool - 2 - and twist the grooving tool through the threaded bushing - 1 -.
The resistance from the groove will be noticeably larger.
Press the threads of the threaded bushing - 1 - in the wheel bearing housing - A -.
The thread repair is finished if the grooving tool - 2 - turns easily through the threaded bushing- 1 -.
- Brake disc, brake caliper, and wheel installation.