Master Cylinder (ATE Type) — Inspection and Repair (Opel Ascona C)

There are two types of repair kits available for repairing the master cylinder assembly. One is a kit with "loose" seals, and the other, newer kit, is a kit that includes a secondary piston already assembled in a special tube that is used to install the piston. Proceed according to what type of set you have.

1. After removing the unit from the machine, clean off any external dirt.

2. Remove the fluid reservoir from the cylinder body.

3. Remove the snap ring from the end of the cylinder housing. To do this, it is necessary to press lightly on the primary piston using a rod in order to relieve the tension of the spring ring.

4. Remove the primary piston, paying attention to how the seals are installed.

5. Insert the rod and push the secondary piston so that the lock screw can be removed from the cylinder body (Figure 9.33).



6. Remove the secondary piston by tapping the end of the cylinder on a wooden block. Pay attention to how the seals are installed.



7. Inspect the piston surfaces and cylinder bore for rust, scratches, or metal-to-metal friction. If this is the case, replace the entire master cylinder.

8. If the components are in good condition, clean them in hydraulic fluid or methylated spirits - and nothing else.

9. Get a repair kit that contains all the necessary spare parts.

Procedures for working with a set of "free" seals.

10. Install new seals on the pistons, using only your fingers to push them into place. It is important that the new seals are installed in exactly the same way as the old ones; they are cone shaped and will only function properly if installed in the correct order.

11. Assembly is carried out in reverse order. Be extremely careful when driving the pistons into the cylinder bores to avoid cutting the seal lips. Before assembly, soak each component in clean hydraulic fluid. Always install a new snap ring from the repair kit.

12. Install new rubber sealing rings and place the fluid reservoir in its place on the cylinder body.

13. Pour some clean fluid into the reservoir and prepare the master cylinder for operation before installation by pressing the primary piston several times with a rod. Naturally, a large amount of liquid will be ejected from the open ports of the cylinder.

Procedures for working with a set of ready-made assembly.

14. Lubricate the cylinder with brake fluid.

15. Clamp the cylinder in a vice with soft jaws so that the barrel is more or less horizontal. Tighten the locking screw slightly, but not so far that it protrudes into the barrel.



16. Remove the large plug from the tube. Remove all components from the short section of the tube and push the short section into the long section until they are flush.

17. Insert the tube into the cylinder barrel up to the flange on the short cuff. Using a blunt rod, push the secondary piston into the barrel until it reaches the end of the cylinder. Tighten the lock screw, remove the rod and collar, and fully tighten the lock screw.

18. Change the position of the master cylinder in the vice so that the barrel opening faces upward.

19. Lubricate the primary piston skirt and seal grooves with the special grease included in the repair kit. Install the retaining gasket onto the piston.

20. Adjust the tube so that the end of its long section is flush with the inner flange of the short section.

21. Install the front oil seal onto the primary piston with the open end of the oil seal facing the front of the master cylinder. Place the tube over the cylinder to compress the seal, insert the piston and tube into the barrel some distance and remove the tube.

22. Place the middle ring on the piston, then install the other seal using the tube in a similar manner.

23. Place the end gasket on the primary piston, then press the piston lightly and install the snap ring. Make sure the snap ring is in place and that the piston can move freely.

24. Install new sealing rings and put the fluid reservoir back in place.

25. Prepare the cylinder for operation by pouring clean brake fluid into the reservoir and pressing on the pistons with a rod so that fluid flows out of all the holes.