Unibloc Lobe Pump 4551AF1-10-10AF30H-82-30B-12a-V

4.0 Gearbox Maintenance and Service

1. Disconnect power and disengage hydraulic or PTO motor before servicing.

2. Depressurize system and close valves on suction and discharge sides.

3. Disconnect piping and remove the pump from the system.

4. If flange-mounted to motor, remove four bolts (9) and unmount the pump.

5. Remove the wet end components (cover, rotors, housing, shaft seals) before gearbox disassembly.

Reference: Figure 4.1 (Items 7, 8, 10, 11a, 12, 13, 21, 23)

1. Drain oil by removing drain plug or cover (7).

6.0 Relief Valve Cover Settings and Maintenance

1. UNIBLOC pumps may come with relief valve covers to prevent over-pressurizing the pump.

2. Cover 3237 works in one direction and must have discharge side at inlet.

3. Cover 3239B works in both directions and adjusts pressure via spring compression.

4. Adjustments must be made while pump is running at desired flow rate.

5. Use caution when handling hot pumps or valves — wear protective gear.

6.1 Setting the Relief Valve Cover

6.1.1 Setting Relief Valve Cover: P/N 3237

1. Unscrew housing (10) to expose adjusting mechanism.

Step 1: Preparation for Shaft Seal Removal

Reference: Figure 3.0, Items 1, 2, 3a, 3b, 14a, 14b, 16

Shut down and disconnect the hydraulic or PTO drive.

Ensure all energy sources are locked out.

Close suction and discharge valves.

Depressurize the pump and remove it from the system if necessary.