HF Repair Manual Ref 300623 Rev.
GENERAL PUMP INDEX 1. 2. 3. 4. 5. A member of the Interpump Group HF SERIES INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 3 REPAIR INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 2.1 Crank Mechanism Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 2.1.1 Crank Mechanism Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL PUMP A member of the Interpump Group 1. INTRODUCTION HF SERIES This manual describes the instructions for Repairing HF Series pumps, and must be carefully read and understood before performing any repair intervention on the pump. Correct use and adequate maintenance is fundamental for the pump’s regular operation and long wear. General Pump declines any responsibility for damage caused by the misuse or the non-observance of the instructions described in this manual. 2. REPAIR INSTRUCTIONS 2.
GENERAL PUMP A member of the Interpump Group HF SERIES 2.1.1 Crank Mechanism Disassembly The correct sequence is the following A) Disassemble: • pump shaft key • rear cover • connecting rod cap • side covers using 3 wholly threaded M6 x 50 screws, inserting them in the opposite holes as shown in fig. 2 B) Push the plunger guides and connecting rods forward in order to facilitate the lateral extraction of the pump shaft. Two marks are visible on the crankshaft, as shown in fig.
GENERAL PUMP A member of the Interpump Group HF SERIES 2.1.2 Crank Mechanism Assembly After cleaning the crankcase, reassemble the crankcase mechanism as follows: A) Thoroughly fit the plunger guide seals into their seat on the crankcase as shown in fig. 5a, using the appropriate tool (p/n F27904900).
GENERAL PUMP A member of the Interpump Group HF SERIES Before assembling the cover (sight glass side), be sure that the shim rings have been inserted. To help the covers fit onto the crankcase, we advise to use 3 screws M6 x 40, and then finish the operation with the screws supplied (M6 x 18) as shown in fig. 6. D) Install the connecting rod cap respecting numbering, and fasten the relevant bolts (lubricating both the head and the threaded stem (proceeding in three different steps. See fig. 7: 1.
GENERAL PUMP A member of the Interpump Group HF SERIES A) Assembly / Disassembly of the crankshaft without replacing the bearings After removing the side covers, as indicated in paragraph 2.1.1, check the rollers and their races for wear; if all parts are in good condition, fully clean the components with a suitable degreaser and grease them again evenly using the same oil in the crankcase. The same shims can be used again, being careful to fit them under the cover on the site glass side.
GENERAL PUMP A member of the Interpump Group HF SERIES The shim pack must be reassembled as follows: A) Insert the crankshaft in the crankcase, being sure that the P.T.O. shank comes out of the correct side. B) Fit the P.T.O. side flange to the crankcase paying close attention to the seal lip as indicated in paragraph 2.1.2, section C. C) Position the flange on the sight glass side as indicated in paragraph 2.1.2. D) Use a thickness gauge (see fig. 10).
GENERAL PUMP 2.2 Fluid End Repair A member of the Interpump Group HF SERIES 2.2.1 Disassembly of the Head - Valve Units Service operations are limited to valve inspection or replacement if needed, and in any case within the intervals indicated in the table in fig. 14, Chapter 11 of the Owner’s Manual. The valve units are assembled inside the head in a vertical position. For their extraction proceed as follows: Unfasten the 8 M14 x 40 valve cover screws (fig.
GENERAL PUMP A member of the Interpump Group HF SERIES Disassemble the inlet and outlet valve units by screwing on an M8 screw long enough to act on the valve and extract the valve guide from the valve seat (4, fig 17). If the inlet valve seats remain glued to the head (for example due to incrustation caused by prolonged pump inactivity), operate as follows: For HF18A version, use tool p/n’s F26019400, F27513700 and F27513400 (fig. 18 and fig. 19).
GENERAL PUMP A member of the Interpump Group 2.2.2 Head Assembly - Valve Units HF SERIES Pay careful attention to the state of wear of the various components; replace them when necesary, and in any case within the invervals indicated in the table in fig. 14, Chapter 11 of the Owner’s Manual. At each valve inspection, replace all valve unit and valve plug O-rings and anti-extrusion rings. Before repositioning the valve units, clean and completely dry the relevant seats in the head as indicated in fig.
GENERAL PUMP A member of the Interpump Group HF SERIES 2. Furthermore, for the HF18A version be careful not to invert the sperical inlet valve with the “A” outlet valve (fig. 23 and fig. 24), exploded view position #46, as indicated in Chapter 16 of the Owner’s manual Insert the inlet and outlet valve units with their related bushings checking that they are thouroughly inserted in their seat on the head.
GENERAL PUMP B) A member of the Interpump Group HF SERIES Extract the high pressure seals from the head, and the low pressure seals from their related support by using standard tools as shown in 5, fig. 26; be careful not to damage the seats. Pay careful attention to the order of sealing pack disassembly as shown in fig. 27 for HF22A and HF25A version pumps, and fig. 27a for HF18A version composed of: 1. 2. 3. 4. 5. 6. 7, 8.
GENERAL PUMP A member of the Interpump Group HF SERIES 2.2.4 Plunger Unit Disassembly The plunger unit does not require periodic maintenance. Service interventions are limited to visual inspections only. for plunger unit extraction operate as follows: Unfasten the M7x1 plunger screws as shown in fig. 28. Check them for wear; replace if necessary. At each disassembly, all the O-rings of the plunger unit must be replaced. 2.2.
GENERAL PUMP A member of the Interpump Group 3. SCREW CALIBRATION HF SERIES Screw calibration by means of a torque wrench only. Exploded View Position Fastening Torque Fastening Torque (From Owner’s Manual) (Ft. Lbs.) (Nm) Cover fastening screws 9 7.4 10 Plunger fastening 29 14.8 20 Conrod caps fastening screws 16 28 38* Head fastening screws 39 59 80** Valve cover screws 41 132.8 180*** Lifting bracket fastening screws 63 73.8 100 Oil discharge plug 11 29.
GENERAL PUMP A member of the Interpump Group 4. REPAIR TOOLS HF SERIES Pump maintenance may be carried out using simple tools for assembling and disassembling components. The following tools are available: For Assembly: • • • • • • • • • Gasket Bushing Ø 32; HP alternative seal ring Ø18x32x7/4.5 . . . . . . . p/n Gasket Bushing Ø 35; HP alternative seal ring Ø22x35x7/4.5 . . . . . . . p/n Gasket Bushing Ø 38; HP alternative seal ring Ø25x38x7/4.6 . . . . . . .
GENERAL PUMP MAINTENANCE LOG A member of the Interpump Group HF SERIES HOURS & DATE OIL CHANGE GREASE PACKING REPLACEMENT PLUNGER REPLACEMENT VALVE REPLACEMENT GP Companies, Inc. 1174 Northland Drive Mendota Heights, MN 55120 Phone:651.686.2199 Fax: 800.535.1745 www.generalpump.com email: sales@gpcompanies.com Ref 300623 Rev.
