Repairs (cont'd)
High-Pressure Inlet Check Ball Travel
The amount of allowable ball travel is critical to the
optimum high pressure output (flow rate). Refer to Figure
A5-1. Carefully and accurately measure (depth "mike")
the "A" dimension (top of pump block to seated ball)
and "B" dimension (top of pump block to head of plug—
at center). Carefully and accurately set the "C" dimension
(overall length of assembled plug and pin) of a
new plug and pin equal to "A" minus "B" minus
.305 ± .050 mm (.012 ± .002 inches).
42
Low Pressure Pump Drive Pin
Assemble with cone point end in half-round keyway.
Greenlee Textron Inc. / Subsidiary of Textron Inc.
980 Hydraulic Power Pump
TOP OF
79
105
PUMP BLOCK
B
A
C
TRAVEL
.305 mm
(.012 inch)
Figure A5-1
5
Figure A6
78
Ball Seat Refinishing
Refer to Figures B2, B3, and B4 for the proper drill size
to refinish the conical seat and finish ream size. These
operations must be performed with the pump or valve
block properly held and using a drill press. Only a very
small amount of material should be removed.
3.175 mm (.125) Ø REAM
4.76 mm (.187") Ø BALL SEAT
(P.O. VALVE)
7.14 mm (.281") Ø DRILL
11.51 mm (.453") Ø DRILL
6.35 mm (.250") Ø BALL SEAT
(LO-P RELIEF VALVE)
4.76 mm (.187") Ø REAM
Figure B2
Figure B3
7.94 mm (0.312") Ø BALL SEAT
(LINE CHECK VALVE)
23
4455 Boeing Dr., Rockford, IL 61109-2988 815/397-7070
3
7
COVERPLATE
8.43 mm ("Q" 0.332") Ø DRILL
4.76 mm (0.187") Ø BALL SEAT
(INTAKE CHECK)
3.45 mm (#29 0.136") Ø REAM
4.76 mm (0.187") Ø REAM
7.14 mm (0.281") Ø BALL SEAT
(DISCHARGE CHECK)
9.35 mm ("U" 0.368") Ø DRILL
9.35 mm ("U" 0.368") Ø DRILL
7.14 mm (0.281") Ø BALL SEAT
(BYPASS CHECK)
4.76 mm (0.187") Ø REAM
4
5
7.14 mm (0.281") Ø REAM
9.53 mm (0.375") Ø DRILL
Figure B4
8