| Symptom | Probable Cause |
|---|---|
| Brake pedal feels soft or spongy with increased travel | Worn internal seals; hydraulic leakage or internal bypass |
| Visible brake fluid leakage (under pedal, around master cylinder) | Damaged/worn master cylinder seals; external fluid leak |
| Brake pedal fails to return or returns slowly | Failed return spring or stuck piston inside master cylinder |
| Vehicle pulls to one side during braking | Uneven pressure between circuits; imbalanced front/rear braking force |
| Increased stopping distance | Master cylinder unable to provide adequate hydraulic pressure |
| Brand | Model | Compatible Engine | Notes |
|---|---|---|---|
| ISUZU | 100P | 4JB1 | Light-duty truck |
| ISUZU | NPR94 | 4JB1 | Light/medium-duty truck |
| ISUZU | NPR | 4HG1, 4HF1, 4HE1, 4HK1 | Light/medium-duty truck |
| ISUZU | NQR | 4HG1 | Medium-duty truck |
| ISUZU | NKR | 4JB1 | Light-duty truck |