Service Manual
Disassembly (Fig. 18)
1. Remove shaft seal (see Shaft Seal Replacement).
2. Remove relief valve (see Relief Valve Service).
3. Matchmark the gear housing with the stator for prop-
er orientation of these parts during reassembly.
IMPORTANT: Use caution when using a vise to
avoid distorting any pump components.
4. Secure flange end of pump in a vise with drive shaft
facing down.
5. Remove eight (8) screws.
6. Support gear housing (Item 18) and gently tap hous-
ing with a soft face hammer to loosen from stator (Item
24). Separate gear housing from stator
. Be careful not
to drop any parts or disengage gear mesh.
7. Before removing gears (Items 19 and 20), apply
marking dye to mating teeth to retain “timing” and loca-
tion for reassembly purposes.
8. Remove drive gear (Item 20) and woodruff key (Item
13) from drive shaft.
9. Remove idler shaft assembly (Items 12, 19, and 21)
from stator
. Remove crescent rings and then idler gear
(Item 19) from idler shaft.
10.Locate and remove dowel pins (Item 23) from stator
or gear housing.
IMPORTANT: When removing gasket (Item 22) from
pump, note gasket color
. Use new gasket of same
color for reassembly.
11. Remove gasket from between gear housing and sta-
tor.
12.Remove retaining ring (Item 1) from stator.
IMPORTANT: Do not try to pry seal out of stator.
This can damage the shaft seal bore.
13.Press drive shaft and bearing assembly (Items 2, 3,
14, 12, and 4) out of stator
. Remove and discard seal
(Item 2). Remove spacer (Item 3) from drive shaft.
IMPORTANT: When removing bearing and crescent
rings from drive shaft, do not slide bearing or cres-
cent rings over seal area of drive shaft.
14.Remove inner crescent ring, then remove bearing
and second ring from drive shaft.
Inspection
1. Wash all parts in cleaning solvent.
2. Check all parts for burrs, scoring, nicks, etc.
3. Clean seal bore and drive shaft of pump so they are
free of any foreign material.
4. Check needle bearings in stator and gear housing
for
excessive wear or damage. If gears (Items 19 and 20),
needle bearings (Item 15), gear housing, or stator are
excessively worn, scored, or damaged, replace pump.
5. Check bearing (Item 4) for smooth operation. Re-
place bearing if loose on shaft or noisy when rotated.
6. Inspect woodruff key (Item 11) and keyway in shaft
for wear or damage and replace parts as necessary
.
Reassembly (Fig. 18)
IMPORTANT: When installing bearing and crescent
rings o
n drive shaft, do not slide bearing or crescent
rings over seal area of drive shaft.
1. Install outer crescent ring on drive shaft (Item 14),
then install bearing (Item 4) and second crescent ring.
Slide
drive shaft and bearing assembly into stator.
2. Install spacer (Item 3) on drive shaft.
3. Use a seal sleeve or tape on drive shaft to protect
seal during installation. Position new seal (Item 2) onto
shaft with part number facing out.
4. Use a seal installation tool to install new seal. Make
sure seal is installed square with seal bore and that seal
is pressed just below retaining ring groove.
5. Install retaining ring (Item 1).
6. Install woodruf
f key (Item 13), then apply clean Dex-
ron III ATF to drive gear (Item 20), and install to drive
shaft.
7. Install one crescent ring to idler shaft
(Item 21), then
install idler gear (Item 19) and second crescent ring. Ap-
ply clean Dexron III ATF to gear and idler shaft assem-
bly, then install into stator maintaining the original timing
and locations.
8. Install new gasket (Item 22) onto stator. Use same
color gasket as the removed gasket.
9. Install dowel pins (Item 23). Assemble gear housing
to stator using the matchmark made during
disassem-
bly. Install screws and tighten in a crossing pattern from
1
14 to 150 in–lb (13 to 17 N–m).
10.Install relief valve (see Relief Valve Service).
11. Place a small amount of Dexron III A
TF in pump inlet
and rotate pump one revolution. If binding is noted, dis-
assemble pump and check for assembly problems.
Hydraulic
System
Multi Pro 1200/1250 Page 4 – 23 Hydraulic System