IMPLEMENT AND STEERING HYDRAULIC SYSTEM CONTINUED
d. Tilt Hold
When the control valve spools are in the HOLD position, pump oil flows to the inlet passage. Oil flows around the
flow control valve and into metering slots which moves the flow control valve against the spring. Pump oil also
flows through the inlet passage to the next control valve.
Since all the valve spools are in the HOLD position, pump oil fills the parallel oil passages of the control valves. The
pump maintains oil pressure at 525 psi (3,600 kPa). Signal oil passage, chamber, and resolver are drained. Rod
end passage, head end passage and passage are blocked.
Figure 31. Bulldozer Tilt Control Valve (HOLD).