Disassembly And Assembly Of Travel Ppc Valve Assembly - Komatsu PC88MR-10 Shop Manual

Disassembly and assembly of travel PPC valve assembly

Disassembly
(PC88MR-C6V0-530-K-00-A)
1. Remove screws (20), and remove damper
assembly (19).
2. Remove mounting bolt (17), and remove case
(16), shaft (15), and lever (13) together as a unit.
3. Remove mounting bolt (11), and remove plate
(10).
a Check and record the thickness and
installing position of washer (12).
a Pull out pin (22) from body (1).
4. Remove seal (9) and collar (8).
5. Pull out piston (7) and remove retainer (6),
springs (5), (4), and shim (3).
a Check the thickness and quantity of the
shims at each installing position, and store
them.
6. Pull out valve (2) from body (1).
Assembly
(PC88MR-C6V0-710-K-00-A)
Only precautions for assembly is described.
a Carefully clean and inspect the parts to prevent
failure due to dust, rust, and scratch, etc., and
then take extreme care when assembling them.
a When assembling piston (7), apply grease (G2-
L1) to the piston periphery and inner periphery of
body (1) hole.
a When installing spring (4), install the end surface
of the smaller end turn diameter to shim (3) side.
End turn diameter of spring (inside diameter)
Small diameter side: 4.9 mm, large diameter
side: 5.55 mm
Apply grease (G2-LI) to the sliding surface of
shaft (15), to the contact surfaces of lever (13)
and piston (7) and to the contact surfaces of
damper (19) and pin (18).
PC88MR-10
50 Disassembly and assembly
Grease (G2-LI)
Contact surfaces of lever and piston: 0.3
to 0.8 cc/place
Contact surfaces of damper and pin: 0.3
to 0.8 cc/place
If difference between right and left at lever full
stroke is larger than 0.7 deg. when installing
washer (12) (t = 1.6), change the washer
thickness to reduce the difference to 0.7 deg. or
less. (By reducing washer thickness by 0.3 mm,
full stroke angle increases by 0.39 deg.)
Washer type and thickness = 1.0, 1.3, 1.6, 1.9,
2.2 mm
a Tightening torque of each part is as following.
Bolt (17): 25 to 30 Nm {2.5 to 3.2 kgm}
Bolt (11): 27 to 34 Nm {2.8 to 3.5 kgm}
Hydraulic system
(PC88MR-C6V0-926-K-00-A)
50-157