Product Description
Cummins 4988807 — Fuel Injection Line (Cylinder #5), 5.9L ISB
MPN: 4988807 | Also Known As: injector fuel supply tube, high-pressure injector line | Application: Ram 5.9L ISB common-rail (’03–’07); see industrial note below
Why This Part
- ✓ OE high-pressure line for cylinder #5—restores factory fuel delivery.
- ✓ Direct-fit formed steel line with OE tube ends for proper sealing.
- ✓ Eliminates leaks from fatigue, vibration, or corrosion.
- ✓ Built to Cummins specs for durability under rail pressure.
Quick Specs
| Type | High-pressure injector fuel supply tube / line |
|---|---|
| OE Part # | 4988807 (cylinder #5) |
| Qty Required | 1 per engine (sold individually) |
| Material | Formed steel line with OE tube ends |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 2003–2007 | Ram 5.9L ISB (24V Common-Rail) | Ram 2500/3500 |
Industrial/Off-Highway: Used primarily on Tier 3 ISB/QSB 5.9 applications—verify by ESN before ordering.
Often Paired With
- Matching lines: #1 (3957081), #2 (4988810), #3 (4988809), #4 (5289447), #6 (4988806)
- Line retainers/clamps and new injectors as needed
What’s In The Box
- (1) Genuine Cummins Fuel Injection Line — Cylinder #5 (4988807)
- Retainers/hardware sold separately (reuse or replace as needed).
Install Tips
- Route exactly like OE; do not bend the line. Start tube nuts by hand.
- Torque to factory spec per service manual; recheck for leaks after warm-up.
- Keep connections surgically clean to protect injectors and pump.
FAQ
WILL THIS FIT MY 2003–2007 5.9L CUMMINS RAM?Yes—this is the OE high-pressure line for cylinder #5 on 2003–2007 5.9L ISB common-rail Ram 2500/3500 (verify by VIN/ESN).
WHICH CYLINDER IS “#5” ON THE INLINE-6?Cylinders are numbered front to rear (1–6). #5 is the second from the rear. Confirm routing in the factory service manual.
DOES THIS COME WITH FITTINGS?The OE line arrives pre-formed with integrated tube nuts. Reuse your clamps/retainers or replace if damaged.
SHOULD I REPLACE ALL LINES AT ONCE?Not required, but recommended if corrosion, vibration damage, or injector replacement suggests multiple lines are compromised.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 4988807 for proper fit and sealing under common-rail pressure.
