Suzuki UY125 Service Manual page 26

2-14 PERIODIC MAINTENANCE
FRONT BRAKE FLUID REPLACEMENT
• Remove the handlebar cover. (!5-5)
• Place the motorcycle on a level surface and keep the handle-
bar straight.
• Remove the front master cylinder reservoir cap and dia-
phragm.
• Suck up the old brake fluid as much as possible.
• Fill the reservoir with new brake fluid.
' Specification and classification: DOT 4
• Connect a clear hose 1 to the air bleeder valve and insert the
other end of the hose into a receptacle.
• Loosen the air bleeder valve and pump the brake lever until
the old brake fluid is completely out of the brake system.
• Close the air bleeder valve and disconnect the clear hose. Fill
the reservoir with new brake fluid to the upper end of the
inspection window.
% Air bleeder valve: 7.5 N·m (0.75 kgf-m)
AIR BLEEDING FOR THE FRONT BRAKE FLUID CIRCUIT
Air trapped in the fluid circuit acts like a cushion to absorb a
large proportion of the pressure developed by the master cylin-
der and thus interferes with the full braking performance of the
brake caliper. The presence of air is indicated by "sponginess"
of the brake lever and also by lack of braking force. Considering
the danger to which such trapped air exposes the machine and
rider, it is essential that, after remounting the brake and restor-
ing the brake system to the normal condition, the brake fluid cir-
cuit be purged of air in the following manner:
• Fill up the master cylinder reservoir to the "UPPER" line.
Place the reservoir cap to prevent entry of dirt.
• Connect a clear hose 1 to the air bleeder valve, and insert
the free end of the pipe into a receptacle.
• Front brake: Bleed the air from the air bleeder valve.
http://mototh.com