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Standard procedures
Removing the pump
Before working on the pump, clean the outside of the pump. If the pump has an auxiliary pump attached,
remove both pumps as a single unit. Tag and cap all hydraulic lines as they are disconnected and plug all
open ports to ensure that contamination does not enter the system.
C
Caution
Contamination can damage internal components and void your warranty. Take precautions to ensure
system cleanliness when removing and reinstalling system lines
Disassembly
1. With the prime mover off, thoroughly clean the outside of the pump.
2. Tag, cap, and disconnect each hydraulic line connected to the pump. As hydraulic lines are
disconnected, plug each open port, to ensure that dirt and contamination do not enter the system.
3. Remove the pump and its auxiliary pump (if applicable) as a single unit.
Inspection
1. Ensure the work surface and surrounding area are clean and free of contaminants.
2. Inspect the system for contamination.
3. Look at the hydraulic fluid for signs of system contamination, fluid discoloration, foam, sludge, or
small metal particles.
Reassembly
1. Before replacing the pump on the machine, replace all filters and drain and fill the hydraulic system
with the correct hydraulic fluid.
2. Flush the lines before replacing the hydraulic fluid.
Shaft seal and shaft replacement
You can replace the shaft and seal without major disassembly of the unit. Clean pump and surrounding
area thoroughly. Disconnect and remove the pump from the unit, and clean it thoroughly before starting
repairs. Mark all connections for later reassembly.
Shaft removal
1. Position the pump with the shaft facing up.
If the unit is positioned horizontally, or moved or jarred while the shaft is out, the cylinder block could
move out of place, making shaft installation difficult.
2. Remove the three or four screws (L70) holding the retainer plate (L60) and seal carrier (L30) to the
housing, using a 10 mm hex wrench (042 unit), a 5 mm internal hex wrench (055 through 100 units),
or a 6 mm internal hex wrench (130 through 250 units). Remove the retainer plate.
Certain earlier production units use a one piece retainer plate and seal carrier.
3. After removing the screws, the spring force on the shaft may move the seal carrier out of its bore by
approximately 5 mm [1/4 inch]. If the seal carrier does not move from its bore, pry it from its bore
and/or lightly tap the end of the shaft with a soft mallet.
4. Remove the O-ring (L50) from the seal carrier and discard.
5. Place seal carrier and seal in an arbor press and press out the seal (L40).
Service Manual
Series 90 Pumps
Minor repair
42
520L0818 • Rev 0101 • August 2015