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MudMaster Diesel-Powered Pump Units

We are the original designers and manufacturers of the MudMaster MM420DT and MM435DT mud pumps. For over 35 years, we have built and supported the best pump packages in the industry. With over 1,000 units in service, you are assured of a quality product and after-sales support.

MudMaster Models MM420BT, MM420DT, MM435DT, and MM450DT


  • 12V electric starting and charging.
  • Manual throttle and stop levers.
  • Fuel transfer pump.
  • 4 speed transmission with integral reduction gear provides ratios of approximately 13:1, 9:1, 5:1, and 3:1.
  • Pressure relief valve.
  • Fuel/water separator.
  • Battery rack and cables.
  • Single point lifting bail.
Model Specifications
 Features Belt-drive Transmission drive
420BD 420DT 435DT 450DT
Flow Rates per minute (US gpm (L))
Ball  valves:
First gear n/a 5.5 (21)  11.3 (43) 12.2 (46.4)
Second gear n/a 7.9 (30) 16.4 (62) 17.7 (66.9)
Third gear n/a 14.2 (54) 29 (112) 31 (120.9)
Fourth gear n/a 20 (77) 37 (141) 40 (152)
Disc valves:
First gear n/a 7.7 (29) 15 (57)  22 (83)
Second gear  n/a 11 (42) 22 (83) 33 (125)
Third gear  n/a 19.9 (75.6) 39 (147) 59 (223)
Fourth gear  n/a 28 (106.8) 50 (190) 75 (284)
Kubota three cylinder, liquid-cooled diesel engine.  Yes
Intermittent BHP at 3000 rpm. 23 25
12 volt electric starting and charging system.  Yes
Glow plug assisted starting.  Yes
Replaceable spin-on tube and fuel filters.  Yes
Primary fuel/water separator.  Yes
Dry type replaceable air filter.  Yes
Fuel transfer and priming pump.  Yes
Exhaust silencer. Yes
Throttle control. Yes
Gear selector. Yes
Clutch actuator. Yes
MudMaster transmission with integral 3:1 reduction. n/a Yes
Four forward speeds to provide pump input speeds of 169, 244, 440 and 733 rpm at 2200 engine rpm. n/a Yes
8″ automotive clutch assembly directly connected. n/a Yes
Spicer output flange positively aligned to heavy duty pump coupling with guard. n/a Yes
FMC (Bean Royal) core drill style ball valve model (standard). L0918 W1122 L1122
Features Belt-drive Transmission drive
420BD 420DT 435DT 450DT
Other Features
Welded structural steel base frame with coped ends for ease of transport and installation. n/a Yes
Heavy construction, removable radiator guard. Yes
Bolt-on, structural steel, single point lift ball. Yes
Full flow, replaceable lube, fuel and air filters. Yes
Primary fuel filter/water separator. Yes
Fuel transfer and priming pump.  Yes
Guarded coupling. n/a Yes
Easy access for service and maintenance.  Yes
Adjustable pressure relief valve with steel plumbing.  Yes
Fully load tested and serviced including lube oil and antifreeze.  Yes
Enamel paint finish.  Yes
Owner’s manual  Yes
Fuel storage tank.  Yes
Starting battery (Group 24).  Yes
Custom paint colours.  Yes
Spare parts kit.  Yes

MudMaster 420DT Pump Unit Spec Sheet PDF-Icon 1 darkback 2

MudMaster 435DT Pump Unit Spec Sheet PDF-Icon 1 darkback 2

Model Images
Left hand side view
  1. Heavy gauge removable radiator guard.
  2. Exhaust silencer shown in vertical position.
  3. Dry type air cleaner with replaceable element.
  4. Bolt-on single point lifting bail.
  5. Gear selector.
  6. Clutch actuator.
  7. Transmission assembly, four speeds.
  8. Adjustable pressure relief valve.
  9. FMC (Bean Royal) L0918B-CD (420) pump assembly.
  10. Welded structural tube skid base.
Right hand side view.
  1. Spin-on replaceable fuel filter.
  2. Primary fuel filter/water separator.
  3. Start/Stop water resistant panel.
  4. Kubota three cylinder diesel engine.
  5. 12V DC battery.
  6. Throttle control.
  7. Coupling with guard.
Front view
Rear view
Left hand side
  1. Heavy gauge removable radiator guard.
  2. Exhaust silencer shown in vertical position.
  3. Gear selector.
  4. Clutch actuator.
  5. Bolt-on single point lifting bail.
  6. Transmission assembly, four speeds, with integral reduction gear.
  7. Adjustable pressure relief valve.
  8. FMC (Bean Royal) W1122B-CD (435) pump assembly.
  9. Welded structural tube skid base.
Right hand side
  1. Coupling with guard.
  2. Throttle control.
  3. Dry type air cleaner with replaceable element.
  4. Start/Stop water resistant panel.
  5. Kubota 3 cylinder diesel engine.
  6. Spin-on replaceable fuel filter.
  7. Primary fuel filter/water separator.
Front view
Rear view

MudMaster MM315

20 US gpm at 700 psi (78 L at 48.2 bar)

MM315 04 1.3

  • Single cylinder Kubota OC95 diesel engine rated 9.5 hp.
  • Close coupled 6:1 reduction gear box.
  • Driving an FMC E0413C pump.
  • Grid style coupling between reduction and pump.
  • Key start.
  • Battery rack and cables.
  • Throttle control.
  • Relief valve.
  • Steel tube skid and protective cage.

MudMaster Hydraulic-Powered Pump Units


  • Axial piston hydraulic motor for pressure and flow compensated systems.
  • Skid base.
  • Inline drive.
  • Guarding.
  • Pressure relief valve.
  • Marine enamel paint.
  • Lifting bail.
  • Plumbing and controls for hydraulic circuit not included.
  • Requires 14 GPM hydraulic flow.
Model Specs
Features 420HB and 420HD 435HB and 435HD 450HB and 450HD
Pump FMC (Bean) L0918B-CD triplex piston. FMC (Bean) W1122B-CD triplex piston. FMC (Bean) L1122B-CD triplex piston.
Pump output rating 25 US gpm at 800 psi.
  • 435 HB (ball valves): 37 US gpm at 1000 psi (140 L at 69 bar).
  • 435 HD (disc valves): 50 US gpm at 1000 psi (190 L at 69 bar).
  • 450 HB (ball valves): 40 US gpm at 1000 psi (152 L at 69 bar).
  • 450 HD (disc valves): 75 US gpm at 1000 psi (284 L at 69 bar).

MudMaster AC Motor Driven Pump Units


Standard build includes TEFC motor. “Explosion proof” motors are also available. This belt driven unit is easily adjusted and permanently aligned. The triplex piston type pump is simple, rugged and reliable. 50 Hz or 60 Hz motors are available at any common three-phase voltage input. A preset, adjustable pressure relief valve is standard equipment.

Rating is 25 US gpm (95 L) with disc type valves or 20 US gpm (76 L) with ball valves. Disc valves are intended for use with clean fluids and ball valves are suited to drilling mud solutions. The pumps are available with optional materials of construction to suit special applications.

Other pressure and flow ratings are available using the wide range of FMC piston and plunger pumps.

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