Relief Valve Maintenance - Doosan D35S-5 Disassembly/Assembly

Assembling Spool Section Assembly
The combination numbers shall in accordance with
the pertinent Parts List.
Tightening torques of each part must be in
compliance with the Parts List.
1. Assemble O-ring(4) and wiper(5) in the seal hole
on the spool head side of the valve hosing (1). Fix
the seal plate(3) with screw(15).
2. Insert the sub-assembled spool(2) from the
opposite side of the valve hosing(1). Cover with
cap(6) and fix with screw(13).
Confirmation of Assembly Work
【Cautions for Assembling Work】
Check if there is any unassembled, missing part
after assembling. Missing part may cause oil leak.
Pressure Adjustment after Assembling
As shown in the main relief valve and second relief
valve(Fig. 6-1), loosen the adjust kit(5) to release
pressure in all the circuits. Set the engine at the
rated rpm, block the circuit and slowly adjust the
pump port pressure to be the set pressure indicated
in the drawing, with the adjust kit(39). When
adjusted, tighten and lock with nut.
Vehicle Systems

Relief Valve Maintenance

Main Relief Valve, Second Relief Valve
Disassembling
The combination numbers shall be in accordance
with the attached Part List(P/N: C0003-30020) and
Fig. 6-1.
Loosen the lock nut on the adjust kit (5) and remove
Spring (3) and pilot poppet (2) from the plug (4).
Since the pilot seat (1) has a hole at the end of the
Plug, do not disassemble it.
【Cautions for Disassembling Relief Valve】
Relief valve has to be replaced in assembly unit, in
principle. Do not disassemble it unless necessary.
The main poppet is built in the unload valve, as
described in the paragraph 1.2.
20 Disassembly & Assembly