Brake Valve - Komatsu WA250-6 Shop Manual

SEN03828-00

Brake valve

P1: From HST pump
T1: To hydraulic tank
T2: To steering pump (suction side)
PA: From accumulator (rear side)
1. Rod
2. Inching valve spool
3. Inching valve body
4. Brake valve spool (for rear)
No. Check item
Clearance between inching valve
8
spool and body
Clearance between inching valve
9
guide and body
Clearance between inching valve
10
spool and guide
11
Inching valve control spring
12
Brake valve control spring
13
Inching valve return spring
14
Brake valve return spring
8
10-400
A: To Rear brake
PB: From accumulator (front side)
B: To front brake
5. Brake valve body (for rear)
6. Brake valve spool (for front)
7. Brake valve body (for front)
Tolerance
Standard
size
Shaft
–0.022
22.4
–0.053
–0.022
22.4
–0.053
–0.050
12
–0.093
Standard size
Installed
Free length
length
34.7 16.7
35.6 24.0
50.0 49.5
114.9 52.4
Criteria
Standard Clearance
clearance
Hole
+0.033 0.020 –
0 0.086
+0.033 0.020 –
0 0.086
+0.050 0.050 –
0 0.143
Repair limit
Installed
Free length
load
24.5 N
—
{2.5 kg}
113 N
—
{11.5 kg}
19.6 N
—
{2.0 kg}
147 N
—
{15.0 kg}
400 Brake system

Brake valve

Unit: mm
Remedy
limit
0.096
0.096
0.157
Replace
Installed
load
20.8 N
{2.1 kg}
96 N
{9.8 kg}
16.7 N
{1.7 kg}
125 N
{12.7 kg}
WA250, 250PZ-6
1