Centurion P8 Belt Drive Triplex 3500 PSI 5.5 GPM Pressure Washer Bare Pump – 85.120.190B

Built for power, endurance, and precision — the professional-grade pump designed for heavy-duty cleaning and long-life performance.

Heavy-Duty Power Meets Long-Lasting Reliability

The Centurion P8 Belt Drive Triplex Pressure Washer Pump (85.120.190B) is engineered by CP, one of the world’s most respected pump manufacturers, to deliver industrial-grade performance and durability. Combining 5.5 gallons per minute of steady water flow with a maximum pressure of 3,500 PSI, this belt-driven powerhouse provides unmatched cleaning capability and longevity.

Built for gas or electric motors, the Centurion P8 (Model CTB4S) is a favorite among professionals in construction, agriculture, and industrial maintenance. Its low-RPM belt drive system reduces friction and heat, while the nickel-plated brass manifold, ceramic plungers, and external unloader ensure long-term durability, smooth performance, and easy serviceability.

This is the pump you choose when your business depends on consistent, all-day performance — engineered to clean harder, last longer, and run cooler than standard direct drive units.

Technical Overview

• PMR PART #: 85.129.190B

• BARE PUMP PART #: 85.120.190B

• PUMP MANUFACTURER: CP

• PUMP MODEL: CTB4S

• DRIVE TYPE: Belt Drive (Gas / Electric)

• SHAFT SIZE: 24 mm

• PUMP STYLE: Triplex

• MAX PSI: 3,500

• MAX GPM: 5.5

• UNLOADER TYPE: External

• PLUNGER (PISTON): Ceramic

• INLET SIZE: 3/4" GHF

• DISCHARGE SIZE: 3/8" Brass QC

• SOAP INJECTOR: Adjustable

• MANIFOLD TYPE: Nickel-Plated Brass

• RPM: 1,450

• MAX INLET TEMP: 60°C / 140°F

• THERMAL RELIEF VALVE: 85.300.024

• OIL CAPACITY: 32 fl oz

• OIL TYPE: 30W Non-Detergent

• WEIGHT: 27.5 lbs

• WARRANTY: 7 Years

Built for the Demands of Professional Cleaning

The Centurion P8 represents the pinnacle of industrial-grade pump engineering. Its triplex plunger design ensures smoother water flow, consistent pressure, and quieter operation. With 3,500 PSI of power and a generous 5.5 GPM flow rate, this pump can tackle large-scale cleaning jobs — from fleet washing and building exteriors to industrial equipment and concrete restoration.

Its belt drive system allows the pump to run at a controlled 1,450 RPM, significantly lower than the 3,400+ RPM typical in direct drive pumps. This slower operation reduces heat and mechanical stress, dramatically extending the life of seals, bearings, and plungers.

When performance and durability matter most, the P8 stands above the rest.

Key Features

Triplex Ceramic Plunger Design

The P8’s triplex plunger configuration features three precision-ground ceramic pistons that move in perfect synchronization. Ceramic provides outstanding hardness and low friction, reducing heat buildup and preventing scoring or corrosion. The result: a smoother, more efficient pump stroke and a longer service life under high pressure.

Nickel-Plated Brass Manifold

The nickel-plated brass manifold is built for the harshest environments. Nickel plating adds a layer of protection against oxidation and chemical corrosion, ensuring the manifold remains strong and leak-free even after thousands of operating hours. Unlike cast aluminum, brass maintains structural integrity and tight sealing under high thermal and mechanical loads.

External Unloader System

The external unloader provides easy access for adjustments, service, or replacement. It allows precise control of system pressure and helps protect the pump and engine from pressure spikes. External unloaders also improve cooling during bypass operation, keeping the pump running safely during idle cycles.

Adjustable Soap Injector

The adjustable chemical injector allows for flexible detergent application, giving you control over flow and concentration. Apply cleaning agents precisely when you need them, then switch back to high-pressure rinse with ease.

Thermal Relief Protection

The thermal relief valve (85.300.024) protects the pump from overheating by automatically releasing heated water during bypass operation. This simple yet essential safeguard prevents damage to seals and plungers, ensuring consistent performance over years of use.

High Oil Capacity for Longer Service Life

With 32 fl oz of 30W non-detergent oil, the P8’s oil-bath crankcase provides continuous lubrication and efficient cooling for internal components. The large capacity reduces maintenance frequency and extends service intervals, keeping your operation running smoothly.

Belt Drive Design: Power and Precision

The belt drive configuration separates the engine or motor from the pump, allowing for lower operating speeds and reducing vibration and heat transfer. This design extends the life of both pump and power source while delivering smoother performance.

Benefits of Belt Drive Pumps:

• Low RPM Operation (1,450 RPM): Reduces wear and noise.

• Cooler Running: Lower internal temperatures mean longer seal and bearing life.

• Less Vibration: Protects internal components and engine mounting hardware.

• Increased Lifespan: Typically lasts twice as long as direct drive units.

• Flexible Power Compatibility: Works with both gas engines and electric motors.

The Centurion P8’s 24 mm shaft is designed for standard pulley fitment, allowing seamless integration into new builds or pump replacements.

High-Flow Performance for Heavy-Duty Cleaning

At 5.5 gallons per minute, the P8 provides enough flow to cover large surface areas quickly while maintaining steady pressure for tough cleaning jobs. This flow-to-pressure balance makes it versatile enough for everything from delicate rinsing to stripping paint and grime from industrial equipment.

Common Applications Include:

• Fleet & Vehicle Washing: Removes heavy dirt, grease, and oil from trucks and buses.

• Concrete & Masonry Cleaning: Strips away grime, mold, and construction residue.

• Industrial Maintenance: Ideal for factory floors, equipment, and facility upkeep.

• Agricultural Equipment: Keeps tractors, sprayers, and harvesters clean and corrosion-free.

• Property & Building Exteriors: Restores brick, siding, and pavement with precision control.

The P8’s 3500 PSI / 5.5 GPM rating hits the sweet spot for professionals who need powerful, continuous-duty performance with efficiency and reliability.

Built to Run Cool and Quiet

Heat is the enemy of longevity. That’s why the P8’s low-RPM, belt-driven design, combined with ceramic plungers and high-quality seals, ensures optimal thermal efficiency. The pump runs cooler for longer, even during full-day use.

This results in:

• Reduced risk of thermal expansion or seal fatigue.

• Quieter operation — ideal for professional environments.

• Extended oil life and fewer service intervals.

The thermal relief valve further enhances protection, automatically venting hot water to maintain safe internal temperatures.

Maintenance and Serviceability

The Centurion P8 was engineered for minimal downtime and easy maintenance. Its external unloader and accessible fittings make it simple to inspect, adjust, or replace key components.

Recommended Maintenance Routine:

• Check oil level before each use; replace after the first 50 hours, then every 500 hours.

• Inspect drive belts for proper tension and wear.

• Clean or replace inlet filters regularly to prevent debris damage.

• Flush chemical injector after use to prevent clogging.

• Ensure thermal relief valve operates correctly to maintain cooling efficiency.

With regular care, the P8 delivers thousands of hours of consistent, high-performance operation.

Installation and Compatibility

The P8’s 24 mm shaft and compact design make it compatible with a wide range of gas engines and electric motors. It mounts easily in belt-drive configurations using standard pulleys and keyways.

Installation Steps:

1. Secure the pump to a stable mounting base.

2. Align the belt pulleys for proper tension and tracking.

3. Attach the 3/4" GHF inlet and 3/8" brass QC discharge fittings.

4. Fill the crankcase with 32 fl oz of 30W non-detergent oil.

5. Adjust the external unloader for desired operating pressure.

6. Test for leaks and ensure proper rotation direction before full operation.

Once installed, the P8 delivers consistent, smooth performance with minimal vibration — the hallmark of Centurion reliability.

Built for Professionals

From the materials used to the engineering precision, the Centurion P8 CTB4S is built for serious professionals who need dependable performance. Its features reflect real-world demands:

• 5.5 GPM flow for faster cleaning and rinsing.

• Nickel-plated manifold to resist corrosion and extend service life.

• Ceramic plungers for heat resistance and durability.

• External unloader and adjustable injector for operational flexibility.

• Thermal relief protection to safeguard seals and bearings.

• 7-year warranty for peace of mind.

When uptime and efficiency matter, the P8 delivers — day after day, job after job.

Built to Outlast the Competition

The Centurion P8’s belt drive, low-RPM design, and industrial-grade construction make it one of the most durable pumps in its class. Unlike direct drive models, which can overheat during extended operation, the P8’s reduced friction and lower operating speed enable continuous-duty performance in professional applications.

Each pump undergoes precision testing at the factory for flow, pressure stability, and seal integrity — ensuring consistent results straight out of the box.

Backed by a 7-Year Warranty

Every Centurion pump is built to meet the highest industry standards. The P8 Belt Drive Triplex Pump comes with a 7-year manufacturer’s warranty, reflecting CP’s confidence in their design and materials. This warranty covers manufacturing defects and guarantees that your pump will perform as expected through years of heavy use.

Professionals choose Centurion because reliability isn’t optional — it’s engineered into every component.

Product Highlights

• Model: CTB4S (Centurion P8)

• PMR Part #: 85.129.190B

• Bare Pump #: 85.120.190B

• Drive Type: Belt Drive (Gas / Electric)

• Pressure / Flow: 3,500 PSI @ 5.5 GPM

• RPM: 1,450

• Manifold: Nickel-Plated Brass

• Plungers: Ceramic

• Unloader: External Adjustable

• Soap Injector: Adjustable

• Thermal Relief Valve: 85.300.024

• Oil Capacity: 32 fl oz (30W Non-Detergent)

• Weight: 27.5 lbs

• Warranty: 7 Years

The Centurion P8 Belt Drive Triplex 3500 PSI 5.5 GPM Pressure Washer Pump (85.120.190B) is a professional-grade powerhouse engineered for high-demand applications. With its nickel-plated brass manifold, ceramic plungers, belt drive system, and external unloader, it delivers exceptional performance, reliability, and longevity.

Running at a cool, efficient 1,450 RPM, the P8 provides smooth, steady power for gas or electric pressure washer systems, with the durability to withstand long daily use. Backed by a 7-year manufacturer’s warranty, it’s the ultimate choice for contractors, facility maintenance crews, and industrial professionals who demand the best.

Centurion P8 — Industrial strength, professional precision, and a lifetime of performance.