Contents: Rear O-ring ↓ Front O-ring ↓
Rear O-ring
Scheme for checking the condition of the rear sealing ring for leaks
1 – master cylinder; 2 – vessel; 3 – adapter with seal; 4 – pressure gauge; 5 – tee; 6 – adjusting screw; A – air from the compressor; B – air release
Leak test
1. Install the master cylinder on the stand (see fig. Scheme of checking the condition of the rear sealing ring for tightness), while ensuring a good seal between the cylinder flange and the mating surface of the stand.
2. Attach vessel 2 with hydraulic fluid to the cylinder.
3. Open the compressed air valve with the adjusting screw 6 unscrewed, then slowly close the adjusting screw until air comes out of the vessel 2.
4. Check the air pressure using a pressure gauge; it should be at least 0.05–0.08 MPa (0.5–0.8 kgf/cm²). If the pressure is lower, replace the rear sealing ring.
Front O-ring
Scheme of checking the condition of the front sealing ring for tightness
1 – bleed screw; 2 – tap; 3 – pressure gauge with a division value of 0.2 MPa (2 kgf/cm²); 4 – pressure gauge with a division value of 0.005 MPa (0.05 kgf/cm²); 5 – vessel; 6 – pusher; 7 – master cylinder
Leak test
1. Install the master cylinder on the stand and connect it to a vessel filled with hydraulic fluid and pressure gauges (see fig. Scheme of checking the condition of the front sealing ring for tightness).
2. Close the pressure gauge valve 3 and, by moving the master cylinder pusher, ensure a stable pressure of 0.2 MPa (2 kgf cm²).
3. With the plunger secured and no fluid leaking, the pressure should remain constant for 2 minutes.
4. Close the pressure gauge tap 4 and open the pressure gauge tap 3. By moving the pusher, set a stable pressure of 10 MPa on the pressure gauge (100 kgf/cm²).
5. With the pushrod secured and no fluid leaking, the specified pressure should remain constant for at least 2 minutes. Otherwise, replace the front sealing ring.