jcb JS200 Service Manual page 291

Section E
33 - 3
Assembly
*
Note:
1. During assembly, be careful when handling the 'O'-rings as follows.
a. Check for defects due to improper handling or from manufacturing.
b. Apply grease to the 'O'-ring and to the area where it is fitted.
c. Do not pull the 'O'-ring so hard that its shape is permanently changed.
d. Do not install the 'O'-ring in a twisted state. (It is difficult to return a twisted 'O'-ring to its original state and this can be the
cause of oil leakage).
2. Be careful when handling the spools and check the following.
a. Excessive torque causes defective operation of the spool so observe the set torque.
b. Be sure that each spring and spool are reassembled in the original state.
3. Applying adhesives. (Male and female screw parts requiring adhesive).
a. Cleansing (Degreasing)
Steam degrease with acetate or use alkaline cleansing agent. Do not use gasoline or kerosene as cleansers.
b. Drying
Blow with clean air or dry naturally and dry the adhesive surface. If not dried sufficiently, the adhesion effect diminishes.
c. Primer application
Spray (Loctite Primer T), hardening agent, lightly on the adhesion surface and wait 3~5 minutes for it to dry.
b. Applying adhesive
Apply a small amount to the spool end and 2~3 threads of the plug male screw. Be careful that this surface does not
come into contact with the spring seat when installing.
* Assembly, 5-spool control valve section
1. Assemble the poppet 20 and spring 19 into the spool 2. After completely degreasing the screw part of the plug (Hexagonal
24 A/F) 16 which has the 'O'-ring 17 and backup ring 18 attached (degrease the spool side too), apply adhesive (Loctite
271 or equivalent) and screw in the spool, with a torque of 9.8-12Nm (7.23-8.67lb/ft).
2. Assemble the spring seat 8 and spring 9, 68 in the spool end 10 (Hexagonal 22 A/F), apply adhesive to the thread and
screw into the spool 3, 4, 5, 6 with a torque of 9.8-12Nm(7.23-8.67 lb/ft).
3. Install the spool assembly into the valve housing 1 in the same position and direction as when disassembling.
4. Assemble the sleeve 51 fitted with the 'O'-ring 50 and backup ring 49 into the valve housing, assemble the poppet 52
and spring 53 and push in the plug 56 complete with the 'O'-ring 54 and backup ring 55 (Check direction of plug 56).
5. Fit the cap 11, 14 with 'O'-rings 7, 15 fitted and tighten socket head bolts (Hexagonal socket 8 A/F) to the valve housing,
with a torque of 39-44 Nm(28.93-32.53 lb/ft).
6. Install the port relief valve 45 (Hexagonal 31.5 A/F) to the valve housing, with a torque of 78-88 Nm (57.84-65.07 lb/ft).
7. Install the plug assembly 36 (Hexagonal 27 A/F), with a torque of 59-69 Nm (43.38-50.61 lb/ft).
8. Assemble the poppet 24, spring 23 into the valve assembly and install the 'O'-ring 22 to the plug 21 (Hexagonal 27 A/F) and
screw it in, with a torque of 83-93 Nm (61.45-68.68 lb/ft).
9. Assemble the poppet 28 and spring 27 into the valve assembly and install the 'O'-ring 25 to the plug 26 (Hexagonal 27 A/F)
and screw it in, with a torque of 267-275 Nm (195.21-202.44 lb/ft).
10. Assemble the poppet 28 and spring 31 to the sleeve 46 and assemble to the valve assembly. Install the poppet 47 and
spring 48. Assemble the sleeve 29, poppet 44 and spring 43 with the flange 70 71 and tighten with socket head bolt 72
(Hexagonal socket 8 A/F), with a torque of 57-65 Nm (41.93-47.71 lb/ft).
11. Install the 'O'-ring 66 to the plug 65 (Hexagonal 36 A/F) and screw it in, with a torque of 118-127 Nm (86.76-93.99 lb/ft).
12. Assemble the spring and piston 51 56 to the cap 2 and tighten the plug 49 (Hexagonal 38 A/F) with 'O'-ring 50
fitted, with a torque of 93-108 Nm (68.68-79.53 lb/ft).
9803/6400
Hydraulics
Control Valve JS200/JS240
Section E
33 - 3
Issue 2*