Bosch remanufactured CP3 high-pressure injection pumps for the 5.9L and 6.7L Cummins and the LB7, LLY, LBZ and LMM Duramax, in stock from $899 with free UPS Ground shipping to the lower 48. Rebuilt to OEM specification with new seals and fuel pressure regulator, backed by a 1-year unlimited-mileage warranty, and shipped as an exchange unit so your truck is not waiting on a rebuild.
In stock · Exchange unit
Order the reman CP3, install it, and send your old pump back with the prepaid label for the refundable core deposit. No downtime waiting on a bench. How the exchange program works
Not sure it is the pump?
Low rail pressure has three usual causes and only one of them is the CP3. Read the symptoms section below, or call and describe what the truck is doing: 530-668-0818.
CP3 failure symptoms, and how to tell it from injectors or the lift pump
The CP3 builds the rail pressure the injectors need. When it wears, the engine cannot hold pressure under demand, and the symptoms overlap with two other problems. Sort them before you buy.
- Points at the CP3: long cranking or a no-start with no smoke (pressure never reaches the threshold to fire), a low rail pressure code such as P0087, power that falls off under load or at higher RPM as actual rail pressure drops away from desired, and a truck that starts fine cold but struggles hot.
- Points at the injectors instead: excessive injector return flow bleeding pressure off the rail. A return-flow test takes twenty minutes and separates the two. Smoke, haze and balance-rate spread are injector signs, not pump signs.
- Points at fuel supply: a weak lift pump or a clogged filter starves the CP3, which then cannot build pressure through no fault of its own. Check supply pressure and the filter first; it is the cheapest fix and a common cause of a “bad” CP3 that was not bad. See the lift pump guide.
If you replace a CP3 without ruling out return flow or supply, you can end up with the same symptom and a new pump. When in doubt, call: describing the symptoms usually gets it sorted in a few minutes.
Bosch reman CP3 pumps in stock: fitment, part numbers and prices
| Application | Years | Bosch # | Replaces OEM # | Price |
|---|---|---|---|---|
| 6.6L Duramax LB7 | 2001–2004 | 0 986 437 303 | GM 97720662 / 97208073 | $899 |
| 6.6L Duramax LLY | 2004.5–2005 | 0 986 437 308 | GM 97303762 / 97780091 | $947 |
| 6.6L Duramax LBZ / LMM | 2006–2010 | 0 986 437 332 | GM 97361351 / 97780161 | $949 |
| 5.9L Cummins ISB (Ram 2500/3500) | 2003–2007 | 0 986 437 304 | Mopar R5143425AA / Cummins 3972814 | $949 |
| 6.7L Cummins ISB (Ram 2500/3500) | 2007.5–2018 | 0 986 437 334 | Mopar 68002013AA / Cummins 5264247 | $949 |
Prices are live from our store and include free UPS Ground shipping in the lower 48. Each pump ships with a refundable core deposit; return your old CP3 with the prepaid label and it comes back to you.
Shop all CP3 pumps Duramax injectors
2011–2016 LML Duramax: that is a CP4, not a CP3
GM moved to the Bosch CP4.2 on the LML, and it is the pump behind the LML’s reputation. When a CP4 fails it grinds itself apart and pushes metal downstream through the rails, lines and all eight injectors. We stock the reman LML CP4 for $699, and for a truck that has already had a failure, the fuel contamination kits replace the whole contaminated circuit at once. Thinking about swapping to a CP3? Our CP4-to-CP3 conversion guide covers what is involved.
Why buy your CP3 here
- Bosch factory-authorized diesel center since 1993. We are not a drop-shipper; the pumps come off our own shelf and we can talk you through the install.
- Rebuilt to OEM spec with new seals and fuel pressure regulator, tested before it goes in the box.
- 1-year, unlimited-mileage warranty. No mileage cap for work trucks.
- Free UPS Ground in the lower 48, most in-stock orders out the same or next business day.
- Fitment checked before it ships. Give us the year, engine and the number on your old pump and we will confirm.
CP3 questions
Is the Duramax CP3 the same as the Cummins CP3?
Same Bosch family, different pumps. Mounting, drive, fittings and calibration differ between the Duramax and Cummins applications, and between Duramax generations. Order by engine and year, and match the Bosch number on your old pump if you can read it.
Do I need to prime a new CP3?
Yes. Fill the fuel filter, cycle the lift pump (on trucks that have one) and crank in short bursts until pressure builds. Running a dry CP3 will damage it. Ask us for the procedure for your engine when you order.
What is the core charge?
A refundable deposit added at checkout. Return your old CP3 within 30 days using the prepaid label and it is refunded in full. Any complete, rebuildable core qualifies.
Can you rebuild my CP3 instead?
For the CP3 the faster path is the exchange unit above. If you have a pump you specifically want rebuilt, or an application not listed here, use our mail-in rebuild service and we will tell you whether it makes sense.
Talk to a diesel injection tech
Monday–Thursday 7:00–4:30, Friday until 4:00 PST. Bosch factory-authorized since 1993. Tell us the year and engine and we will confirm the exact part before it ships, or send a message.
