Parts of brake master cylinder with small reservoir
1. Cork and strainer; 2. Tank; 3. Retaining ring; 4. Primary piston with spring; 5. Secondary piston with spring; 6. Locking bolt; 7. Plug; 8. Fitting
Large reservoir brake master cylinder parts
The brake master cylinder is mounted in the engine compartment on a vacuum booster.
Removing
1. Use a syringe to remove some of the liquid from the tank.
2. Place a pallet or a rag under the cylinder.
3. Loosen the tubing fittings on the master cylinder.
4. Disconnect and plug the pipes.
5. Disconnect connector from tank (if provided), unscrew the 2 nuts securing the cylinder to the vacuum booster and remove the cylinder.
Disassembly
Cylinders with a large or small tank are installed on cars, the disassembly and assembly procedures for these units are almost the same, with the exception of reservations.
Purchase a cylinder repair kit before disassembly.
1. On a cylinder with a small reservoir, remove the reservoir mounting bolt.
2. Loosen tank clamps (A) and fitting (IN) and remove the tank.
3. On a cylinder with a large reservoir, unscrew the screw and remove the reservoir.
4. Check the condition of the gasket.
5. Clamp the cylinder in a vise, squeeze the pistons and unscrew the locking bolt. Replace bolt gasket.
6. Depress the pistons again and remove the circlip.
7. Disassemble the cylinder, paying attention to the order of installation of the parts.
8. Remove the primary piston.
9. After knocking on the bar, remove the secondary piston, avoiding distortion, otherwise the cylinder will be scratched.
10. Pay special attention to the springs, which differ for different pistons.
11. Check the condition of the cylinder.
12. If scratches or painted areas are found, replace the cylinder. The cylinder must not be honed.
13. Replace all parts by installing new ones from the repair kit in the same order. Dip the parts in brake fluid before assembling.
14. Collect pistons, enter into the cylinder, wring out and wrap a locking bolt.
15. Install a new retaining ring, making sure that the ring fits into the groove.
16. Install reservoir gaskets and reservoir.
17. When installing, fill the cylinder with liquid.
18. Clamp the cylinder in a vise by the flange, fill the tank with liquid, wrap the plugs and press the piston with a large Phillips screwdriver.
19. Open the plug to let the air out.
20. Close the plug and release the piston.
21. Repeat these steps until fluid starts to come out of the fitting hole. Maintain the fluid level in the reservoir at all times.
22. Repeat the bleed steps for the other hole.
23. Instead of a plug, you can close the hole with your finger.
24. Release your finger after pressing the pistons, after fluid flows out, close the hole with your finger and release the pistons.
25. After a few seconds, press the plunger again and remove your finger.
26. Repeat the procedure and do the same for the other hole.
27. After only liquid begins to flow out of the holes, wrap the plugs.
Installation
1. Reinstall the cylinder and tighten the nuts by hand.
2. Screw the fittings without distortions, manipulating the cylinder.
3. Tighten nuts and fittings.
4. Add liquid to the tank to the upper division and wrap the plug.
5. The air from the cylinder can also be removed by car, working together. To do this, ask the assistant to press the pedal and hold.
6. Unscrew the fitting and release the air.
7. Wrap the fitting and ask the assistant to release the pedal.
8. Continue until liquid begins to flow from the cylinder.