MD6250 Rotary Drill Systems Caterpillar

Main Control Valves

Illustration 1	g06414445

The Rotary Drill utilizes four main hydraulic control valves and two diverter valves to operate all functions. Each control valve is supplied oil from the auxiliary pump. Each diverter valve is supplied oil from either the left or right main pump.

Main Mast Valve One

Illustration 2	g06252978
(1) Main mast valve one (2) Rack swing (3) Pipe rack swing pin (4) Carousel index (5) Carousel lock (6) HOBO swing (7) HOBO clamp/rotate

Mast valve one is located at the base of the mast near the hydraulic breakout wrench.

Oil to the main mast valve (1) is supplied from the auxiliary pump. The main mast valve (1) directs the oil to each circuit as the operator activates a control lever in the cab. The mast valve bank contains sections for the following functions:

• Rack swing (2)

• Pipe rack swing pin (3)

• Carousel index (4)

• Carousel lock (5)

• HOBO swing (6)

• HOBO clamp/rotate (7)

Main Mast Valve Two

Illustration 3	g06252988
(8) Hydraulically operated bit basket (HOBB) (9) Deck wrench (10) Pipe positioner (11) Pipe catcher (12) Main mast valve two

The main mast valve two is located on the mast near the base of the mast.

Oil to the main mast valve (12) is supplied from the auxiliary pump. The main mast valve (12) directs the oil to each circuit as the operator activates a control lever in the cab. The mast valve bank contains sections for the following functions:

• HOBB (8)

• Deck wrench (9)

• Pipe positioner (10)

• Pipe catcher (11)

Auxiliary Valve Bank

Illustration 4	g06252998
(12) View hatch (13) Dust curtain (14) Mast lock (15) Cascading stairs (16) Auxiliary valve

The auxiliary valve is located under the cab near the rear of the machine.

Oil to the auxiliary valve (16) is supplied from the auxiliary pump. The auxiliary valve (11) directs the oil to each circuit as the operator activates a control lever in the cab. The auxiliary valve (11) contains sections for the following functions:

• View hatch (12)

• Dust curtain (13)

• Mast lock (14)

• Cascading stairs (15)

Jacks and Masts Raise Valve

Illustration 5	g06354093
(17) Jacks and mast raise valve (18) Winch (19) Left rear jack (20) Right rear jack (21) Front jacks (22) Mast raise (23) Dust collector / water injection

The jacks and mast raise valve is located near the base of the mast near the left side mast raise cylinder.

Oil to the jacks and mast raise valve (17) is supplied by the auxiliary pump. The jacks and mast raise valve (17) directs the oil to each circuit as the operator activates a control lever in the cab. The jacks and mast raise valve (17) contains sections for the following functions:

• Winch (18)

• Left rear jack (19)

• Left rear jack (20)

• Front jacks (21)

• Mast raise (22)

• Dust collector / water injection (23)

Diverter Valves

Illustration 6	g06253089
(24) Right diverter valve (25) Left diverter valve

The diverter valves are located at the base of the mast between the mast raise cylinders.

Oil to the right diverter valve (24) is supplied from the right travel and rotation main pump. Oil is diverted between the right travel motor or the rotation motor depending upon which position the drill travel switch is in. Oil to the left diverter valve (25) is supplied from the left travel and hoist/pulldown main pump. Oil is diverted between the left travel motor or the hoist and pulldown functions depending upon which position the drill travel switch is in.