4.1 Technical data
Model
Master pump
Wheel-type brake
type
IV. Brake System
Front two wheel brake, hydraulic type
TCM3t, cylinder bore 0.75in
Separated pump cylinder bore
Brake drum inner diameter
TCM self-enforcing shoe-type brake with parking brake
(TCM,
21/31 brake)
1.13in
12.2in(2t,2.5t);12.36(3t)
4.2 Overview
The brake system is two-front-wheel brake type which consists of master pump, brake and brake
pedal mechanism.
4.3 Master Pump
The master pump includes one valve seat, one single-way valve, one return spring and seal cup,
piston and assisting seal cup. The ends are fixed by thrust ring and thrust steel wire. The outside part
is protected by rubber dust-proof cap. The master pump piston type, moves through push rod by
operating the brake pedal. When stepping on the brake pedal, the push rod pushes forward the piston,
the brake liquid of the pump body flows back to oil storage tank though the oil return port, till the
main seal cup block the oil return port. After the main seal cup pushes over the oil return port, the
brake liquid of master pump front chamber will be compressed and open the single-way valve, and
flow to separated pump through brake pipeline, so that each separated pump piston will extend out to
make brake shoe friction plate contact the brake drum and realize the speed-down and stop the
Forklift. At this time, the return spring of piston rear chamber presses backward, in the meantime,
all the brake liquid inside each separated pump will be compressed by brake shoe return spring, and
will flow back to mast pump (piston front chamber) through single-way valve. The piston will
return to original position. The brake fluid of master pump flows to oil tank through oil return
port. The single-way valve pressure is adjusted in proportion to the balance pressure inside the
brake separated pump, which put the separated seal cup in right place to avoid oil leakage, and
remove the possible air blocking during emergency brake. (Fig. 4-1 brake master pump)
105
4.4 Wheel brake (Fig. 4-2)
The wheel brake is of inner expansion and fluid type, it consists of brake shoe, spring, separated
pump, regulator and bottom plate. The two brakes are installed on each end of front axle. When
stepping on the foot brake pedal, the push rod pushes brake master pump piston and presses the brake
liquid of master pump cylinder into brake separated pump cylinder, then pushes separated pump
piston, and makes the brake shoe pressed on the brake drum to stop the wheel.
Fig. 4- I Master brake pump
1 � valve body
1
2
,
thrust ring
3� piston
4,
front seal cup
5,
bush seal cup
6,
main sealcup
1
7
,
spring seat
8, spring
9,
cut-off valve
10,
valve seat
IL
protection cover
112,
push rod
13,
support lug
14,
nutM8
15,
rubber bush
16, connector
I
4.4.1 Change the brake shoe
A� Stop the
F
orklift on flat concrete ground.
106
Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
