The Berkeley B87336 B3JRMBMS high-pressure hydraulic water truck pump replaces the legacy B73403. It combines 4-inch suction and 3-inch discharge female NPT connections with clockwise rotation, a mechanical seal, and an SAE C 4-bolt mount with a 1-1/4-inch, 14-tooth splined drive. Choose it when replacing an existing B73403 or specifying a hydraulic-drive water truck pumping system.
The B87336 retains the predecessorβs external mounting arrangement while updating the impeller inlet eye, wear ring, and internal volute machining. That preserves the replacement fit without treating the new internal components as interchangeable service parts. For repairs, identify the pump by its current B/M number rather than ordering internal parts solely from the older B73403 listing.
Hydraulic drive with a familiar replacement fit
A matched hydraulic drive lets the pump serve a water truck installation without a direct PTO-to-pump driveshaft connection. The motor, hydraulic supply, and controls must still be sized for the selected water-side duty; matching the mounting flange alone does not establish adequate power.
| Feature |
Benefit |
| B73403 replacement |
Retains the existing SAE C mounting arrangement for replacement planning. |
| 4-inch suction Γ 3-inch discharge |
Accepts matching male-NPT piping or adapters at the suction and discharge ports. |
| SAE C hydraulic interface |
Supports a matched hydraulic motor rather than a direct pump driveshaft. |
| Mechanical seal |
Maintains the mechanical-seal configuration of the predecessor. |
Technical specifications
| Specification |
Configuration |
| Manufacturer / part number |
Berkeley / B87336 |
| Model / legacy number |
B3JRMBMS / replaces B73403 |
| Pump type |
Single-stage centrifugal; hydraulic drive |
| Suction / discharge |
4-inch / 3-inch, female NPT |
| Mount / drive |
SAE C 4-bolt / 1-1/4-inch, 14-tooth spline |
| Rotation / seal |
Clockwise (CW) / mechanical seal |
Approximate performance at 2,600 RPM
Use these three operating examples to compare a higher-pressure duty with a higher-flow duty. All three points are at the same 2,600 RPM pump speed; they are not simultaneous maximum ratings.
| Water flow |
Approximate differential pressure |
| 600 GPM |
185 PSI |
| 900 GPM |
165 PSI |
| 1,200 GPM |
125 PSI |
The figures are approximate readings from the manufacturer-supplied performance curve for fresh water at 68Β°F. Pressure is the pumpβs differential head expressed in PSI, not a guaranteed nozzle or discharge-gauge pressure. Inlet pressure and downstream losses affect gauge readings and delivered nozzle performance. The curveβs 266 PSI maximum working-pressure rating is a separate limit, not an advertised output pressure or a rating for every component in your system.
Match the pump to your water truck
At a fixed speed, the operating point depends on the complete system, not just the discharge port. Nozzle orifice size, valve position, hose and pipe losses, and elevation all affect the flow and pressure the installation delivers. Select the nozzle and piping for the required duty instead of assuming the pump produces one fixed GPM/PSI combination.
| System element |
Selection guidance |
| Existing B73403 installation |
Check mounting, shaft engagement, rotation, and plumbing before replacement. |
| Hydraulic motor and supply |
Match the SAE interface, required speed, torque, flow, and available power. |
| Nozzles, valves, and piping |
Select for the required operating point and the pressure each component can encounter. |
| Suction arrangement |
Check available inlet supply and suction losses to avoid inadequate inlet conditions. |
Before ordering
Specify the pump and drive components separately in your system plan. Confirm the supplied assembly and any required motor, adapters, fittings, hoses, and controls with UnitedBuilt; do not assume that this pump listing supplies a complete hydraulic-drive package.
| Check |
What to confirm |
| Pump identification |
B87336 or the B73403 being replaced; provide a nameplate photo when available. |
| Mounting and rotation |
SAE C 4-bolt, 1-1/4-inch 14-tooth spline, and correct drive rotation. |
| Required duty |
Desired GPM and pressure together, plus available hydraulic power. |
| Operating limits |
Keep hydraulic-drive pump operation within the applicable 1,400β2,700 RPM range; do not use the 3,000 RPM SAE-engine-drive curve. |
| Installation and pressure |
Verify component ratings, inlet conditions, and manufacturer installation requirements. |
Need help confirming the pump for your water truck? Contact UnitedBuilt through online chat, email parts@unitedbuilt.com, or call 602-253-7750 with your application, drive arrangement, and required flow and pressure.
