How to Solve the Problem of No Oil Coming from the Brake Pump?

[CatherineLee]

If there is oil in the pump but no oil comes out when the oil pipe is removed, it may be due to a blockage in the oil hole at the bottom of the upper pump. You can disassemble the upper pump for thorough cleaning and check if there are any issues with the upper pump plunger, etc. If necessary, the upper pump can also be replaced separately. Below are common faults of disc brakes: 1. Brake problems caused by the quality of the upper pump: Some manufacturers make the piston of the upper pump out of plastic, and the quality of the oil seal is also average. Such upper pumps will soon experience oil leakage from the oil seal or loss of pressure. 2. The impact of oil quality on disc brakes: If the disc brake loses pressure again soon after repair, and releasing air can restore normal function, but the same problem reappears after a night, it is likely an issue with the disc brake oil. 3. Rear wheel lock-up: In this case, you need to open the lower pump to vent and observe the oil flow. If the oil spurts out and the rear wheel becomes lighter, it indicates a pressure issue, and the fault may lie with the upper pump or oil pipe. If the oil flows out slowly and the rear wheel remains heavy, it suggests a mechanical problem with the lower pump.