niu N-GT, Service Manual

Page: 49 / 144

V1.0.0 49
Failure diagnosis
No Yes
Yes No
Failure of the hydraulic disc brake
Check the brake liquid level in the main brake pump
reservoir.
The brake liquid level is below the lower
limit scale in the reservoir. The brake liquid level is above the lower
limit scale in the reservoir.
Add the brake liquid to
the upper limit scale in
the
reservoir. Check
the brake caliper, brake
hose and hose joint for
air leakage.
There is air left in the
brake system oil circuit.
Check the brake pad for wearing to the limit
mark. Check the brake disc for excessive
wearing.
Replace the brake pad and brake
disc. 1. Check the main brake pump piston surface and the oil cylinder wall surface for
excessive wearing or damages.
2. Check the main brake pump piston cup for damages, cracks or aging.
3. Check the brake caliper seal ring for damages, cracks or aging.
4. Check the brake caliper piston surface and the oil cylinder wall surface for
excessive wearing or damages.
Is there a "sponge-like" feeling when
operating the brake handle?