Hypro Roller Pumps

New Pump Selector | Repair Kits & Parts | Operation Manual

Parts Lists: 4000, 6500, 7560, 7700, 1700, 1500, 1200

To Take the Pump Apart

1. Remove the adapter from the pump shaft.
2. File off any burrs on the pump shaft.
3. Using a screwdriver, pry off the bearing cover on the endplate and pump body
4. Remove the endplate bolts.
5. Support the pump at its ports in an endplate support fixture with the endplate down. Use wood blocks for Series 1500, 1700 and 4001/4101. Place on press bed. Center press on pump shaft and apply pressure to press the pump apart (See Figure 9).
6. With the rollers exposed, remove them - examining each one carefully for excessive wear. When replacing damaged rollers, always replace the full set.
7. To remove the rotor with shaft from the endplate - support the endplate in an endplate support fixture with the rotor down. Center the bearing disassembly tool or 3/8" bolt, on pump shaft. Apply pressure to press shaft out of ball bearing (See Figure 10).
8. To remove the ball bearing - place the endplate in a endplate support fixture with the front of the endplate down (See Figure 11). Center bearing support tool and
slowly press bearing out of casting. Repeat procedure to remove bearing from pump body (See Figure 12) using body support fixture.
9. After removing the ball bearing, check the seals in both endplate and pump body. If wear is evident or leakage has been noticed, punch the seals out with a screwdriver and hammer. Seals cannot be removed without damaging them.
10. To press the shaft out of the rotor, first carefully wash the rotor and shaft with kerosene - removing all traces of rust and other foreign matter. Use steel wool or emery cloth, rinsing parts afterward to wash off all emery dust. Remove the allen set screw. Support the rotor in the press through the slot in the base and press shaft through.

While the Pump is Apart

Carefully inspect all parts for wear, such as:

• Undersize or swollen rollers in both length and diameter.
• Worn seals.
• Worn shaft at drive end, and pitted or grooved at the seal area.
• Rough bearings and loss of grease from the bearings.
• Undersize rotor and/or worn roller slots.
• Excessive wear in body - both on inside diameter and at back face.
• Body cracks at the bolt holes and at the o-ring sealing area.
• End wear (body, endplate and rotor).
• Proper size o-ring in the endplate.

After the above parts have been checked and the various points have been considered, you can decide if the pump is repairable. When worn parts have been replaced, always take up the end clearance by lightly sanding the endplate and matching body surface (See Figure 13). NOTE: End clearance should not be more than .004 inches.
Inspect Inside of Endplate. If a groove is noticeable, the endplate should be resurfaced by rubbing it on a sheet of 80 grit emery paper (placed on flat surface) until all trace of wear has been removed. Rotate the endplate frequently to remove evenly the same amount of metal over the entire surface. NOTE: This surface of the endplate must be perfectly flat. If attempt has been made to pry pump apart with a screwdriver, file off all nicks, burrs and other damage marks around the bolt holes.

Re-Assembly

Replace Seals and Bearings. Carefully place the seal in the pump body with crimped side down. Press the seal to the bottom of the cavity, using the
stepped end of the bearing & seal assembly tool (Figure 14). Then put the bearing in position in the pump body and press into place with counter-bored end of bearing & seal assembly tool (Figure 15). Repeat the above procedure with the endplate. Seat the o-ring in the groove. If necessary, make sure the o-ring stays in place by stretching it.

Assemble Rotor and Shaft To Endplate
1. Install the shaft rotor assembly by carefully pushing the short end of the shaft rotor assembly through the shaft seal into the endplate. Place in the arbor press with the drive end of the shaft pointed down. Use the bearing support tool on top of the bearing and press the assembly together (Figure 16). Leave just enough clearance between the rotor and endplate so that rotor can be turned by hand. If it turns too freely, sand a little more off the body end that faces the endplate. You should notice a slight drag, but be able to turn shaft with an adapter on it, by hand. The “slight drag” will wear off after the pump has been used a short time. Installing new rollers, seals, bearings and shafts will not prove entirely satisfactory for volume and pressure unless end clearance is taken up.

NOTE: If the endplate has been resurfaced, the body face must also be resurfaced to allow for material taken off the endplate. Follow same procedure as above with emery cloth. Before new parts are installed, all burrs should be removed - particularly in the rotor slots and body.

Do not machine clean the body casting. A more satisfactory job can be done by hand cleaning with an emery cloth. Wettable talc powder mixture (5 lbs. powder to 5 gallons water) can be used for breaking in a repaired pump if pump appears to be binding. Run pump for about 5 minutes. This will also serve to clean and remove corrosion from the pump. Follow with a clear rinse and protect from rust. (See Maintenance.)
2. Remove the assembled portion from the arbor press and invert it on the press table with the bearing support tool under the bearing. Then place rollers in the roller slots as close to center of rotor as possible. Place the pump body over rotor and shaft, and carefully ease the end of the shaft past the lips of the seal in pump body (Figure 17). Center bearing support tool with counter-bored end down on inner race of ball bearing, and slowly press the pump body down to fit the endplate (Figure 18).
3. Turn pump over; line up bolt holes and replace assembly bolts. Alternately and evenly tighten the bolts as shown (Figure 19). NOTE: After bolts have been tightened, check to see if rotor is centered in pump case. Try to turn the pump shaft, using a crescent wrench on the shaft as a lever.

1. Place short brass rod (or hardwood dowel) against end of shaft (Figure 20). Center rod on shaft (not on bearing). Tap lightly with hammer. Try turning shaft again.
2. If this fails to center the rotor to where it can be turned freely - tap other end of shaft, protecting it as above. When the shaft can be turned by hand - using wrench as above - it is not binding.
3. If the pump binds within and tapping does not free it, it may be necessary to “run the pump in” to wear off high spots. Use talc solution mentioned earlier. Check pump frequently during run-in.

Full Instructions are in the Operation Manual.