Product Overview
Reliable custom rubber parts for industrial applications
Quick Answer
The Johnson 09-842B rubber impeller is a flexible vane pump component for replacement, maintenance service and compatible fluid handling applications. Dimensions, blade profile, hub structure, shaft connection, rubber compound, Shore A hardness, tolerance and packaging must be confirmed by drawing, official specification or physical sample before production.
The Johnson 09-842B rubber impeller is a flexible vane pump component used as a replacement reference for compatible pump systems. This page does not assume unconfirmed dimensions, blade quantity, material grade, hardness, color or insert details. Outer diameter, height, hub structure, shaft connection, blade profile and rubber compound should be confirmed by drawing, official specification or physical sample.
Product Overview
The Johnson 09-842B Rubber Impeller is a large-format flexible Neoprene impeller manufactured as a direct-fit replacement for Johnson Pump F98 series engine cooling pumps used across heavy-duty marine diesel engine applications. It is one of the largest impellers in the Johnson Pump flexible impeller range, reflecting its use in high-volume raw-water cooling circuits for larger marine diesel engines. The impeller is manufactured with SPX Flow’s precision tolerances and is available in both standard Neoprene and the specialized MC97 rubber compound for optimized cold-start cooling performance.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 09-842B |
| Pump Model | Johnson Pump F98 |
| Material | Neoprene (MC97 compound also available) |
| Outer Diameter | 95 mm (3.74″) |
| Width | 180 mm (7.09″) |
| Hub Insert Type | Splined (no metal insert — solid spline drive) |
| Approx. Weight | 3.0 kg (~6.6 lbs) |
| Kit Contents | Impeller, O-ring, glycerine/lubricant |
What Is the Johnson 09-842B Impeller?
The Johnson 09-842B is a flexible Neoprene rubber impeller with a solid splined bore, designed for use in Johnson Pump F98 series bronze flexible impeller pumps that circulate large volumes of raw seawater for marine diesel engine cooling. As the pump shaft rotates, the flexible Neoprene blades deform and re-expand within the pump housing to draw in and discharge cooling water — a self-priming action characteristic of flexible impeller pump design. Its large 180 mm width reflects the high-flow cooling demands of the bigger diesel engines it services, making it one of the widest impellers in the standard Johnson Pump impeller range (which spans 0.50″ to 3.48″ in width for smaller models).
Manufacturer Design Features
According to SPX Flow (manufacturer of Johnson Pump), impellers in this series are engineered with the following performance characteristics:
- MC97 rubber compound option — a proprietary rubber formulation offering correct cooling performance at engine start-up and during continued running
- Exact OEM dimensional tolerances — manufactured to strict tolerances for optimal fit and function versus generic aftermarket copies
- Stable pressure delivery over time — designed to maintain consistent cooling flow throughout the service interval, minimizing material failure and swelling
- Excellent self-priming capability — ensures sufficient cooling flow immediately at start-up, even after periods of engine inactivity
- Optimized for infrequent-use applications — engineered to provide maximum impeller life especially where the end user doesn’t run the engine on a regular basis
Related Impeller in Same Family
| Part Number | Pump | Material | Diameter | Width |
|---|---|---|---|---|
| 09-842B | F98 | Neoprene | 3.74″ (95mm) | 7.09″ (180mm) |
| 09-802B | F9 | Neoprene | 3.74″ (95mm) | 3.48″ |
Note: A Nitrile version is generally offered across this impeller family for oil-resistant applications, while Neoprene and MC97 compounds are used for standard cooling duty.
Why Neoprene (and MC97) Is Used for This Impeller
- Wide chemical resistance — Neoprene tolerates prolonged exposure to raw seawater and freshwater typical of heavy-duty engine cooling circuits
- Industry-standard flexibility — Neoprene remains the benchmark material for Johnson Pump’s F98 series large-format flexible impeller family
- Large blade surface area — the 180 mm width provides substantial displacement per rotation, matching the high-volume cooling demands of larger marine diesel engines
- MC97 compound advantage — the specialized compound is engineered specifically to reduce material failure and swelling over long service life, particularly valuable in engines that see intermittent or seasonal use
- Solid spline bore — provides secure, slip-free torque transfer directly from the pump shaft without a separate metal insert
Installation & Maintenance Notes
- Dry-running caution — like all flexible impeller pumps, this impeller must never be run dry, even briefly, as the Neoprene blades can overheat and deform without water lubrication and cooling
- Recommended replacement interval — the manufacturer recommends yearly replacement to ensure the impeller maintains sufficient pumping pressure for reliable engine cooling
- Service kit availability — commonly supplied as a complete kit including O-ring and glycerine lubricant for a full service installation
- Installation orientation — blade curvature must be installed in the correct rotational direction per the pump housing orientation to ensure proper self-priming function
Applications
- Heavy-duty marine diesel engine raw-water cooling circuits using Johnson Pump F98 series pump bodies
- Larger displacement marine diesel engines requiring high-volume cooling water flow
- Commercial marine vessels and larger recreational yacht engine cooling systems
- Applications with intermittent engine use where extended impeller shelf/service life is valued
Custom & OEM Manufacturing Capability
- Material options — Neoprene, MC97-equivalent proprietary compound, NBR (Nitrile) for oil resistance, NR, EPDM, Silicone, HNBR, SBR
- Hardness range — 30–95 Shore A
- Temperature range — -40°C to +300°C depending on compound selection
- Dimensional tolerance — ±0.05 mm
- Hub options — solid spline bore, brass spline drive, key drive, or custom insert configuration
- Certification — ISO 9001 compliant manufacturing available
- Custom branding — OEM and ODM orders accepted with customer logo and packaging
Why Source from Julong Rubber?
- Full dimensional cross-reference matching for Johnson Pump F98 series impellers
- ISO 9001 certified manufacturing and inspection
- Full elastomer range — Neoprene as standard, plus NBR, NR, EPDM, Silicone, and custom compounds
- Precision solid-spline hub molding for secure, high-torque transfer in large-format impellers
- Low MOQ with tiered volume pricing
- Fast delivery for stock cross-reference parts
- OEM/ODM capability — custom logo, packaging, and specification accepted
- Heavy-duty marine diesel application experience across commercial vessels
FAQ
Can this impeller be supplied as a Johnson 09-842B replacement?
Yes, the product can be reviewed as a replacement reference for Johnson 09-842B applications. However, the part number alone is not enough for production approval. Dimensions, blade profile, shaft connection, rubber compound and pump compatibility must be confirmed before manufacturing.
Why are exact dimensions not listed on this page?
Exact dimensions are not listed because no confirmed drawing, official specification or measured sample data has been provided. For rubber impellers, unsupported dimensions can cause installation problems, reduced flow, excessive friction or early blade damage. Confirmed data is required before production.
Can the impeller be manufactured from an old sample?
Yes. A physical sample can be used for reverse engineering when the original drawing is unavailable. The sample should be checked for wear, deformation and blade damage. Critical dimensions, pump chamber clearance and operating conditions should still be confirmed before tooling.
How should buyers select the rubber material?
Rubber material selection depends on the working liquid, temperature, rotation speed, dry-running risk, oil exposure and chemical contact. Buyers should provide the exact media and service conditions. Material selection depends on the application conditions.
Is tooling required for this rubber impeller?
Tooling is usually required for molded rubber impellers with custom blade geometry, hub structure or insert design. Tooling cost depends on the drawing and product structure. Prototype samples can be reviewed before batch production.
Are samples available before bulk production?
Samples are available upon request. Sample preparation depends on the confirmed dimensions, rubber compound, Shore A hardness, insert structure, tooling status and inspection requirements. Please provide a drawing, official specification or physical sample for review.
Request a Custom Quote
Send your Johnson 09-842B rubber impeller drawing, official specification, pump model or physical sample for review. Please include dimensions, shaft connection, blade profile, rubber material, hardness, working liquid, temperature, speed, rotation direction, quantity and packaging requirements.
