Overhaul Seal Kit Instructions - Gravely Promaster 100 Service Manual

12.8 OVERHAUL SEAL KIT INSTRUCTIONS

Use seal kit P/N 58800300 to overhaul pump.
The procedure below is for the disassembly and
replacement of the BDP-10L variable pump end cap
gasket, O-rings, and shaft seal.
Cleanliness is a primary means of assuring satisfactory
hydraulic unit life on either new or repaired units.
Cleaning parts by using a clean solvent wash and air
drying is usually adequate. As with any precision
equipment, all parts must be kept free of foreign
materials and chemicals. Protect all exposed sealing
surfaces and open cavities from damage and foreign
material.
During assembly of the pump all surfaces which have
relative motion between two parts must be coated with
a film of clean oil. This will assure that these surfaces
will be lubricated during start-up.
All gasket sealing surfaces must be cleaned prior to
installing new gaskets.
Charge Pump
The charge pump rotation is determined by the
orientation of the charge pump cover on the end cap.
The cast offset on the charge pump cover indicates the
orientation.
1. Make note of the correct orientation prior to
removing the charge pump cover. Marking the
cover and end cap is the easiest way to insure
proper orientation.
2. Using a 5 mm hex wrench, remove the two screws
holding the charge pump cover to the end cap.
3. Remove the charge pump cover and O-ring.
Remove the charge pump gerotor assembly. Then
remove the charge relief valve spring and ball.
4. Inspect the gerotor assembly, charge pump cover,
and end cap for abnormal wear, damage or foreign
material.
Figure 27 - Charge Pump Components
Disassembly Procedures for the End Cap
1. Using a 6 mm hex wrench, remove the 4 screws
which retain the end cap to the pump housing. The
internal springs should separate the end cap from
the housing. Remove the end cap from the
housing.
CAUTION: The pump cylinder block will stick
to the surface of the end cap. A small
screwdriver between the block and end cap
will aid in separation. Exercise caution to
prevent damage to the end cap and cylinder
block sealing surfaces.
2. Remove the old gasket from the housing.
CAUTION: Do not damage the running
surfaces of the cylinder block.
3. Install a new end cap gasket onto the housing.
4. Lubricate the running surfaces of the end cap and
cylinder block. Position the end cap with the
housing dowel pins, and install the end cap onto
the housing.
CAUTION: Be certain all parts are properly
aligned. Do not force the end cap into position
on the housing. Caution must be exercised to
prevent damage to the end cap and cylinder
block seating surfaces.
5. When the end cap is properly installed, the internal
springs will hold it away from the housing
approximately 3/8" (10 mm).
6. Install the 4 screws which retain the end cap to the
variable pump housing. Torque the screws evenly
to 138-180 in-lbs (16-20 Nm).
Prior to installing the charge pump, apply a small
quantity of clean oil to the ID, OD and side faces of the
gerotor assembly.
Figure 28 - Install Gerotor Assembly and Charge
12 - 42
Relief Valve