Description
R12T Fuel Filter Water Separator — Complete Combo Kit
R12T Marine Fuel Water Separator — 10 Micron, 30 GPH, Replaces Racor S3240 / 120AT, NPT ZG1/4-19. Fits gas & diesel engines on boats, trucks, tractors, and generators. Complete combo kit includes the spin-on filter housing, two inlet/outlet fittings, two plugs, and a reusable clear nylon collection bowl with self-venting drain valve.
📋 Key Takeaways
- ✅ Complete combo kit — no separate parts to buy
- ✅ 10-micron filtration — removes water and particles down to 10 microns
- ✅ 30 GPH flow rate — supports engines up to 300HP
- ✅ NPT ZG1/4-19 ports with M18×1.5 center thread
- ✅ Reusable nylon collection bowl with self-venting drain valve
- ✅ Replaces Racor S3240, 120AT, Sierra 18-7987, RK10222
Features & Benefits
| Feature |
Benefit |
| 10-Micron Filtration Media |
Captures emulsified water and fine particles before they reach your injectors — prevents injector seizure and CP4 pump failure |
| 30 GPH Flow Rate |
Supports high-performance and fleet diesel engines without fuel starvation |
| Clear Nylon Collection Bowl |
Visual inspection of water accumulation at a glance — no guesswork needed |
| Self-Venting Drain Valve |
Tighten to seal, release to drain — service in under 2 minutes without tools |
| Dual-Sided Port Configuration |
Inlet/outlet can run same-side or opposite-side to fit any engine bay layout |
| Powder-Coated Steel Housing |
Electrostatic coating resists corrosion from saltwater, road salt, and diesel fuel |
| Spin-On Design |
Tool-free filter replacement — just spin off the old, spin on the new |
Compatibility & Cross-Reference
| Part Number |
Brand |
| R12T / 120AT |
Racor / Parker |
| S3240 |
Racor |
| 18-7987 |
Sierra Marine |
| RK10222 |
Sierra |
Common Applications
-
Diesel trucks — Duramax, Powerstroke, Cummins fuel system protection
-
Marine engines — Yanmar, Volvo Penta, Mercury, Yamaha outboard/inboard
-
Agricultural equipment — Kubota, John Deere, CAT, Case IH tractors
-
Generators — Cummins Onan, CAT standby generators
-
Off-road equipment — excavators, skid steers, bulldozers
Specifications
| Part Number |
FJ-R12T (iFJF) |
| Filter Type |
Spin-On Fuel Filter / Water Separator |
| Micron Rating |
10 Micron |
| Flow Rate |
30 GPH (114 LPH) |
| Port Size |
NPT ZG1/4-19 (M18×1.5 Center Thread) |
| Bowl Material |
Clear Nylon (Reusable, Self-Venting) |
| Housing Material |
Powder-Coated Steel (Corrosion Resistant) |
| Includes |
1× Filter Assembly, 2× Fittings, 2× Plugs, 1× Nylon Bowl |
Why Choose iFJF?
We built the R12T to match — and in many ways exceed — the OEM Racor specification. Every unit is:
- 🔍 Factory-tested for 10-micron filtration efficiency and 30 GPH flow rate
- 🛡️ Powder-coated inside and out for rust-free service life in marine environments
- 📦 Ready to install — includes fittings, plugs, and drain bowl in one box
- 💰 Priced for boat and fleet owners — premium filtration without the OEM markup
Want to see how the R12T stacks up against the genuine Racor? Read our R12T vs Racor 120A comparison review →
Looking for the upgradable R12H system (replace only the filter element, not the whole housing)? Check out the R12H Filter Element here →
Frequently Asked Questions
What's the difference between R12T and R12H?
The R12T is a complete disposable filter assembly — when it clogs, you replace the entire unit including the housing. The R12H system is upgradeable: you keep the aluminum housing and only swap the filter cartridge. If you do frequent filter changes, the R12H upgrade pays for itself within 2-3 services.
Does this fit my boat/diesel engine?
The R12T fits any engine with NPT ZG1/4-19 (M18×1.5 center thread) ports. It's commonly used on Yanmar, Volvo Penta, Mercury, Cummins, and Kubota engines. The 30 GPH flow rate supports engines up to approximately 300HP. If you're unsure about fitment, contact us with your engine model.
How often should I replace the R12T filter?
Replace every 100-200 hours of engine operation, or annually — whichever comes first. In marine environments or if you use biodiesel, inspect the clear bowl at every fill-up and drain water as needed. Visual inspection: if the bowl shows more than 1/2" of water or the filter media appears dark/saturated, replace immediately.
How do I drain water from the R12T bowl?
Simply loosen the drain valve at the bottom of the clear nylon bowl — water and contaminants will drain out by gravity. Tighten the valve to seal. No tools required. Pro tip: keep a small catch cup under the bowl before opening the valve to avoid diesel on your bilge or garage floor.
Can I use this with biodiesel?
Yes — the R12T is compatible with B5-B20 biodiesel blends. However, biodiesel tends to hold more dissolved water than petroleum diesel, so we recommend more frequent bowl draining (every 25-50 hours) when running biodiesel. The powder-coated steel housing resists the higher corrosion potential of biodiesel blends.
What cross-reference replacements match this filter?
This R12T replaces: Racor S3240 / 120AT, Sierra 18-7987 / RK10222. It shares the same 10-micron rating, NPT ZG1/4-19 port size, and 30 GPH flow rate as the OEM Racor unit — at a more competitive price point.
How do I install the R12T fuel filter assembly?
- Remove the old filter by spinning it counterclockwise (have a catch pan ready for residual fuel)
- Clean the mounting bracket surface and apply a thin film of diesel to the new filter's gasket
- Screw in the two inlet/outlet fittings (choose same-side or opposite-side configuration)
- Install the two plugs in the unused ports
- Spin the new R12T onto the mounting head clockwise until the gasket contacts, then tighten 3/4 turn by hand — do not overtighten
- Prime the system using the manual primer pump and check for leaks at all four ports
Package Includes
- 1 × R12T Fuel Filter / Water Separator Complete Assembly
- 2 × NPT ZG1/4-19 Inlet/Outlet Fittings
- 2 × NPT ZG1/4-19 Plugs
- 1 × Clear Nylon Collection Bowl with Self-Venting Drain
