WELD ON HYDRAULIC THUMB INSTALLATION 

1.1 - POSITION THE BUCKET IN FULL CURL AND CLAMP ON THE BOTTOM MOUNTING PLATE AS SHOWN IN F2. (ALLOW 1”-1.5" INCH CLEARANCE BETWEEN THE MOUNTING PLATE AND THE BUCKET EARS.)

PRO TIP: Lay a 2x4 on its 2" side across the ears of the bucket to create a 1.5" space between the bucket ears and the bottom mounting plate. 

1.2 - SQUARE UP,  CLAMP AND TACK WELD THE BOTTOM MOUNTING PLATE IN PLACE. (MAKE SURE THE TACK WELD OR CLAMP IS STRONG ENOUGH TO HOLD THE MOUNTING PLATE AND THUMB IN PLACE. DO NOT FULLY WELD MOUNTING BRACKET UNTIL THE THUMB FITMENT HAS BEEN TESTED.)

1.3 - INSTALL  THE THUMB PART TO THE MOUNTING PLATE WITH THE MAIN PIN

1.4 - CHECK BOTTOM MOUNTING PLATE CLEARANCE AND THUMB POSITION AS SHOWN IN D1.

2.1 - PIN THE CYLINDER TO THE THUMB PART ( CHROME TIE ROD END ATTACHES TO THE THUMB.CYLINDER SHOULD BE IN RETRACTED POSITION. ) 

2.2 - PIN THE CYLINDER MOUNT TO THE STATIONARY SIDE OF THE CYLINDER 

2.3 - LAY THE CYLINDER AND THUMB PART AGAINST THE STICK OF THE EXCAVATOR MAKING SURE THE TOP MOUNT BACKING PLATE IS TOUCHING THE EXCAVATOR ARM

2.4 - LOWER THE CYLINDER TOP MOUNTING BRACKET DOWN THE ARM BY MOVING THE THUMB PART OUT OFF THE ARM OF THE MACHINE UNTIL THE BACK OF THE THUMB TINE CLEARS THE BOTTOM CYLINDER PORT CLOSEST TO THE THUMB PART. 

PRO TIP: ***( ALLOW FOR A MINIMUM CLEARANCE OF 1/2" FROM THE BACK OF THE THUMB TINNE TO THE FRONT OF THE FITTING FOR THE HYDRAULIC PORT. FAILURE TO DO SO WILL CAUSE THE THUMB TO COME BACK TO FAR AND DAMAGE THE FITTING.***

2.5 - SQUARE UP,  CLAMP AND TACK WELD THE CYLINDER TOP MOUNTING PLATE IN PLACE. ***(MAKE SURE THE TACK WELD OR CLAMP IS STRONG ENOUGH TO HOLD THE MOUNTING PLATE AND CYLINDER IN PLACE. DO NOT FULLY WELD MOUNTING BRACKET UNTIL THE THUMB FITMENT HAS BEEN TESTED.)

3.1 - WITH THE  MOUNTING BRACKETS TACKED SECURELY IN PLACE AND THE THUMB PINNED TO THE BOTTOM MOUNTING BRACKET AND CYLINDER TIE ROD END; AND THE CYLINDER PINNED TO THE TOP CYLINDER MOUNT . OPEN ONE TOP AND ONE BOTTOM PORT OF THE CYLINDER TO LET AIR IN AND OUT.

3.2 - BY HAND MOVE THE THUMB TO MINIMUM AND MAXIMUM CYLINDER STROKE, CHECK THAT CYLINDER IS FREE AND THAT THERE IS NO CONTACT THAT COULD CAUSE DAMAGE. 

3.3 - POSITION THE THUMB 90 DEGREES TO THE FLAT PART OF THE STICK AS SHOWN IN FIGURE D2. ( THUMB SHOULD CONTACT BUCKET CUTTING EDGE OR TEETH TO PREVENT BINDING). THE BUCKET SHOULD ONLY CONTACT THE THUMB IN THIS AREA. THUMB SHOULD BE 15-20 DEGREES OFF STICK WHEN RETRACTED AND EXTEND OUT TO 135 DEGREES, )

PRO TIP: MOVING THE TOP CYLINDER MOUNTING BRACKET UP OR DOWN WILL CHANGE THE EXTENSION AND RETRACTION IF NEEDED 

4.1 INSTALL HOSES AND FITTINGS -  ONE LINE IN TOP PORT OF CYLINDER (FEED LINE) ONE LINE IN BOTTOM PORT (RETURN LINE)

PRO TIP: FOR EASE OF REMOVAL GET QUICK DISCONNECT FITTINGS FOR MACHINE AUX PORT

4.2 REDUCE AUX HYDRAULIC PRESSURE TO 2500PSI ( SOME MACHINES HAVE AN AUX VALVE SELECTOR, THIS IS DONE IN THE CONTROL SETTINGS OR WITH A MANUAL SWITCH ON SOME MACHINES OTHERWISE THERE MAY BE A PRESSURE RELIEF VALVE BLOCK ON THE AUX PORT OF MACHINE. IF YOUR MACHINE DOES NOT HAVE THIS YOU CAN GET AN IN LINE PRESSURE RELIEF VALVE)

5.1 FINISH WELDING MOUNTING PLATES TO BOOM USING 70-18 ELECTRODE. (***FULLY WELD BRACKETS IN PLACE ON TOP & SIDES, LEAVE 1" SPACE  AT BOTTOM MIDDLE OF BRACKETS FOR RELIEF) 

5.2 TEST RETRACTION AND EXTENSION FUNCTION UNDER PROPER PRESSURE FAILURE TO DO SO MAY CAUSE TIE ROD DAMAGE

5.3 REMOVE AND GREASE PINS PRIOR TO USE>

5.4 THUMB IS READY FOR USE.