ARM AS-VALVE RKR 10R1998 - Caterpillar

Introduction
The Hydraulic Control may have one, two or three control valves, dependant upon machine equipment.The dash-mounted hydraulic tank contains the filter and one control valve. The control valve consists of a control valve spool, relief valve and make-up valve. The control valve operates the tool bar in a three-valve system. The valve may be used to operate either a tool bar or a rear attachment in the one and two valve systems.One or two external control valves, mounted to the right fender, operate one or two rear attachments.
This is a view of the hydraulic pump. The components identified are: 1-Pump outlet line. 2-Pump. 3-Inlet supply line to pump.
This is a view of a machine equipped with a tool bar. The components identified are: 4-Tool bar control lever. 5-Hydraulic oil supply tank. 6-Tool bar cylinders (two).The valve in the tank has four positions: RAISE, HOLD, LOWER and FLOAT. The external valve in a two valve system (the rear external valve in a three valve system) has the same four positions. The front external valve in a three valve system has three positions: ROD RETRACT, HOLD and ROD EXTEND.Oil for the system is supplied by a single-section, insert vane-type pump. The pump is mounted on the left rear side of the timing gear cover and is driven by the engine camshaft gear.
This is a view of a machine equipped with a two valve system. The components identified are: 4-Tool bar control lever. 5-Hydraulic oil supply tank. 6-Tool bar cylinders (two). 7-Rear attachment control lever. 8-Filter. 9-Four position control valve for rear attachment. 10-Lines to rear attachment. 11-Return line to tank. 12-Supply line to external control valve.
This is a view of a machine equipped with a three valve system. The components identified are: 4-Tool bar control lever. 6-Tool bar cylinders (two). 7-Rear attachment control lever (four position valve). 10-Rear attachment lines (four position valve). 13-Control lines (three position valve). 14-Rear attachment lines (three position valve). 15-Rear attachment control valves (two).Operation
This is a schematic of a three valve system. The valve spools are in HOLD position. The components identified are: 1-Tank control valve. 2-Relief valve. 3-Check valve. 4-Filter. 5-Make-up valve. 6-Drain line to tank. 7-Front of hydraulic oil supply tank. 8-Tool bar cylinders (two). 9-Pump. 10-External control valve (four position). 11-Cylinder. 12-External control valve (three position). 13-Check valve. 14-Check valve. 15-Cylinder. 16-Drain passage. 17-Drain passage. 18-Float detents (four).Hold Position
The valve spools of the control valves are held in HOLD position by centering springs. The oil in the head ends and rod ends of all the cylinders is blocked.The oil flow through the three valve system when the control levers are in HOLD position is as follows:The pump draws supply oil from the tank. The oil is directed to the control valve in the tank, flows past the valve spool and is directed to the external control valves. The oil flows through the control valves, oil filter and into the supply oil in the tank.
This is a view of the front of the