Product Description

Cummins 3969698 — Genuine P7100 Injection Pump–to–Timing Case O-Ring Seal

MPN: 3969698  |  Also Known As: P7100 pump mounting gasket, timing case O-ring  |  Common Cross-Refs (ID): Cummins 3924605 (family interchange)

Stop fuel seepage at the pump flange. The genuine Cummins 3969698 O-ring seals the joint between the Bosch P7100 injection pump and the gear housing (timing case) on 1994–1998 Ram 2500/3500 5.9L 12-valve trucks. OE elastomer, OE profile—exactly what you need any time the P-pump is removed or reinstalled.

Features & Benefits

• OE sealing profile for the P7100 pump flange to prevent leaks and air intrusion.
• Direct-fit replacement—no trimming or sealant globbing required.
• Maintains case vacuum/pressure integrity for stable fueling and clean starts.
• Genuine Cummins part for consistent material quality and longevity.

Verified Fitment (Automotive)

Industrial/Off-Highway: Cummins catalogs 3969698 as an O-Ring Seal used primarily on Euro II 5.9-liter B-engines. If ordering for equipment or non-automotive engines, verify by ESN.

Specifications

• Type: O-ring (pump mounting / timing case seal)
• OE Part Number: 3969698
• Mates: Bosch P7100 pump flange to gear housing
• Material: OE elastomer (round cross-section)
• Quantity Required: 1 per pump install

Often Paired With

• P7100 rear support bracket: Cummins 4003580 (brace)
• Block-side support: Cummins 3928898
• P7100 mounting hardware/seal kit (studs, nuts, ancillary seals)
• Front cover/timing case gasket set (if the housing is serviced)

What’s In The Box

• (1) Genuine Cummins P7100 Pump–to–Timing Case O-Ring Seal (3969698)

Installation Tips

• Mark pump timing before removal; avoid rotating the pump shaft relative to the gear.
• Clean the groove and mating face; lightly oil the new O-ring. Do not use RTV on the sealing land.
• Seat the pump squarely to prevent pinching; torque fasteners to spec and re-verify timing marks.
• Prime the fuel system and check for leaks after first start.

FAQ

WILL THIS FIT MY 1994–1998 5.9L 12-VALVE RAM?

Yes—3969698 is the OE P7100 pump mounting O-ring for 1994–1998 Dodge/Ram 5.9L 12-valve applications.

DOES THIS FIT 1998.5–2002 24-VALVE (VP44) TRUCKS?

No—VP44 systems use different seals and hardware. This O-ring is specific to the Bosch P7100.

WHERE DOES THIS O-RING INSTALL?

Between the P7100 pump mounting flange and the gear housing (timing case).

ARE THERE ALTERNATE/LEGACY IDS?

Many catalogs cross-list 3924605 (and related family numbers). Match by pump type and ESN when in doubt.

SHOULD I REPLACE THIS ANY TIME THE PUMP IS REMOVED?

Yes—always install a new OE O-ring to ensure a leak-free reassembly.