Brake Valve Service - BRADEN CH400B Installation Maintenance And Service Manual

BRADEN CH400B hoist is supplied with one of two
BRADEN brake valves, depending on the hydraulic mo-
tor used. Both are reliable hydraulic valves with internal
components manufactured to close tolerances. Because
of these close tolerances, several individual parts are not
available as replacement parts and are noted in the fol-
lowing parts list as NSS (not serviced separately).
Before disassembling the brake valve, be sure you have
conducted all applicable troubleshooting operations and
are certain the brake valve is causing the malfunction.
Thoroughly clean the outside surfaces of the valve and
work in a clean dust free area, as cleanliness is of utmost
importance when servicing hydraulic components.
1-1/4 INCH BRAKE VALVE
17 18
19
1
SEC. A-A
DRAIN
PORT
8
7
2
10
ITEM DESCRIPTION
1 Brake valve housing
2 Valve spring retainer
3 Spring retainer
4 Plug
5 Spool
6 Damper piston
7 O-ring
8 Check valve poppet
9 Pilot orifice
10 Check valve spring
11 Spool spring
12 O-ring
13 O-ring
14 O-ring
15 Backup ring
16 Backup ring
17 Steel ball
18 Compression spring
19 Elbow fitting
22 Shim, valve spring

BRAKE VALVE SERVICE

3
22
12
A
11
A
6
14
16
5
9
"BR"
13
PORT
15
4
QTY.
NSS
1
1
1
NSS
NSS
2
NSS
1
1
1
1
1
1
1
1
1
1
1
AR
20 11 10
19
4
5
15
ITEM DESCRIPTION
1 Valve Housing
2 Check Valve Retainer
3 Spring Retainer
4 Plug
5 Main Piston
6 Damper Piston
7 Damper Piston Extension
8 Check Valve Poppett
10 Reducer
11 Check Ball
12 Check Valve Spring
13 Main Piston Spring
14 O-ring
15 Back-up Ring
16 O-ring
17 Back-up Ring
18 O-ring
19 Pipe Plug
20 Check Spring
21 Shim
22 Spring Seat
NSS- NOT SERVICED SEPARATELY - REPLACE
COMPLETE VALVE ASSEMBLY
1-1/2-INCH BRAKE VALVE
1-1/2-inch brake valves built after mid-March 1997 contain
a spring seat (Item 22 above) between the spool spring
and the spool. This provides a slightly larger, more uni-
form area for the spring to seat against the spool. The
result is increased spring service life and improved repeat-
ability of the pressure/flow modulation over the full com-
pression range of the spring.
The spring retainer has been modified to allow for the
additional thickness of the spring seat and a groove
31
19
1 12
2 14
18 17
16 22 6 7
QTY.
NSS
1
1
1
NSS
NSS
1
NSS
1
1
1
1
1
1
1
1
1
1
1
1
1
8
13
3
21
14