Tadano TR-800XXL4, Service Manual

Page: 286 / 402

T - 4 T - 4
Booster (Brake)
21
W404-0012E
2. Function
This booster receives pressurized air from the
relay valve into the air cylinder, and outputs
hydraulic pressure in proportion to the pneumatic
pressure to the wheel cylinders and other
members of the brake system. It comprises the
following three major components.
1. Air cylinder
The air cylinder incorporates air piston assy 8,
return spring 11. The return spring side is always
open to the atmosphere, and the opposite side is
subject to the output pressure of the relay valve.
2. Oil cylinder
Oil piston 14-1 is connected to air piston assy 8 by
piston pin 16, via valve 15, and pin holder 17
prevents the pin from coming off. The pressurized
oil in the oil cylinder is sealed by a tight fit
between the valve in valve 15 and oil piston 14-1.
3. Relay valve
This valve serves to make the brake applied and
released quickly.