Caterpillar 3406 Injection Pump Rebuild Service
The Caterpillar 3406 scroll-type inline injection pump is the big cam-driven pump bolted to CAT’s 14.6L 3406A, 3406B, and 3406C, the engine that pulled a generation of on-highway trucks and still runs gensets, boats, and heavy ag equipment today. Valley Fuel Injection has been rebuilding these pumps the right way for decades. When one wears out, a proper CAT 3406 injection pump rebuild is almost always faster, cheaper, and better than hunting down a replacement pump for a mechanical engine CAT stopped building. We rebuild your own core and calibrate it on the bench to the Caterpillar test plan, so you get a pump matched to your engine’s own rating instead of a mystery exchange unit or a throw-together parts swap.
The Valley Fuel Injection Difference
We are a rare breed. There are not many shops left in the country with the training, the certification, and the test equipment to rebuild a diesel injection pump to factory standard, and fewer still that do it at our level. This is not a cheap imported knockoff and it is not a throw-together seal-kit job. It is a genuine, certified, factory-spec rebuild, done by hand and proven on the bench before it ever leaves the building.
When you send a pump to Valley Fuel Injection, it is rebuilt by licensed, factory-certified diesel technicians, to the same standard the pump held the day it left the factory, and it is backed by a real warranty. That is the whole point of what we do.
Applications We Rebuild
The 3406 went into everything from Class 8 sleepers to standby power. The most common we see:
| Engine / Equipment | Typical Applications |
|---|---|
| On-highway trucks | Peterbilt, Kenworth, Freightliner and other Class 8 trucks running the 3406B and 3406C |
| Gensets & industrial | 3406 stationary power, standby generators, irrigation, and industrial power units |
| Marine | 3406 marine propulsion and auxiliary engines |
| Heavy ag & construction | Large tractors, harvesters, scrapers, and off-highway equipment with the 3406 |
Common 3406 Pumps We Rebuild
Caterpillar ran the mechanical 3406 across a long production life and several ratings. These are the versions that come across our bench:
3406A: Earlier 14.6L 3406 truck and industrial engines
3406B: The classic 3406B on-highway and industrial engine
3406C: Later mechanical 3406C, shares the 3406B pump mount
Important: this service covers the mechanical 3406 only. The 3406A, 3406B, and 3406C use the cam-driven scroll-type inline pump we rebuild here. The 3406E is a different animal. It is electronic, it fuels through electronic unit injectors, and it has no injection pump of this type, so there is nothing here for us to rebuild on one. If you are not certain which 3406 you have, read the tag on the engine and the pump, call 530-668-0818, and we will sort it out with you and quote your rebuild.
Landed here with a different Caterpillar? A CAT customer often lands on the wrong pump page, because the engines get talked about interchangeably and the pumps are not interchangeable at all. If you have the 10.4L V8, you want our CAT 3208 injection pump rebuild service, which uses a sleeve-metering pump. If you have the smaller 3300-series engines, go to our CAT 3304 and 3306 injection pump rebuild page instead. We rebuild all of them, so if you are on the wrong page, call us and we will point you to the right one.
Signs Your 3406 Injection Pump Needs a Rebuild
- Hard starting or long cranking before the engine catches
- Low power under load, or an engine that will not pull the hill the way it used to
- Black smoke under load
- Surging or hunting at governed speed, and governor instability that will not settle down
- External fuel leaks at the pump
- Fuel showing up in the engine oil
- Uneven cylinder-to-cylinder fueling, or a pump that never ran right again after a load of contaminated fuel
How We Rebuild Your 3406 Pump
A Valley Fuel Injection rebuild is not a seal kit and a coat of paint. Every pump is torn completely down and built back to factory standard, one measured part at a time. Here is what actually comes off our 3406 bench:
- Complete teardown and inspection. We disassemble the entire pump and inspect every single component against Caterpillar wear limits. Nothing is reused on assumption.
- Deep cleaning. Every part is ultrasonically and thoroughly cleaned so we are building on bare, spotless metal, not old varnish and debris.
- Plunger and barrel assemblies, matched to your pump. The 3406 ran both single-helix and dual-helix plunger and barrel assemblies, including the large-cam versions, and they are not interchangeable guesses. We identify which your pump takes and fit the right ones, because that is where a scroll pump lives or dies.
- Camshaft and riser bearings. The camshaft is inspected and the riser bearings are replaced, so the plungers are driven by a straight, true cam instead of a worn one.
- Governor shaft and weight carrier. The governor is rebuilt with a new governor shaft, and the weight carrier is replaced with the correct early or late style for your pump. That is what kills the hunting and surging most 3406 owners come to us for.
- Check valves, tappets, and spacers. Check valves, tappets, and spacers are inspected and replaced as needed, then a full gasket set goes in on assembly along with a new finishing kit. On a 3406B or 3406C we fit the correct pump mount kit so it goes back on the engine sealed and located right.
- Calibration and testing on real machines. The finished pump goes on a professional test bench, where per-cylinder fuel delivery, cylinder-to-cylinder balance, and governor settings are calibrated to your pump’s Caterpillar test plan and proven before it ships.
That final step is what separates a real rebuild from a parts swap. Anyone can bolt in a seal kit. Very few shops can put a 3406 pump on a bench, balance it cylinder to cylinder, calibrate it to spec, and stand behind the result.
Our Warranty
We control every step of the rebuild, so we stand behind it. Every pump we rebuild carries a 1-year warranty. Electrical and electronic components are warrantied for 30 days. Clean, water-free fuel is essential to pump life, so we recommend fresh fuel filters at installation to protect your rebuild.
What a 3406 Pump Rebuild Costs
Typical Rebuild Cost
$3,600 to $5,400 typical range
Most Caterpillar 3406 injection pump rebuilds land between $3,600 and $5,400, with a typical rebuild around $4,500. That is our real shop pricing for this pump, not a markup guess. It is a big pump with a lot of parts in it, and pumps with heavier internal wear, or that need a full set of plunger and barrel assemblies, a governor shaft, or a weight carrier, run toward the top of the range. Because every rebuild is priced on your pump’s actual condition, we give you a firm quote after inspection, before any work begins.
Prices above cover the service and parts. Any applicable sales tax, plus shipping and small shop fees (such as a hazardous-waste disposal fee), are added at invoicing, so your quote reflects the full out-the-door number before any work begins. Buying tax-exempt? Qualifying diesel repair shops, fleets, farms, and agricultural operations can purchase tax-free. Set up tax-exempt purchasing by submitting your resale or exemption certificate once, and every qualifying order is tax-free going forward.
How It Works · Call for Pricing and Availability
Because every 3406 rebuild is done on your own core, pricing depends on the pump’s condition and the parts it needs, so we quote each job individually. Here is the process:
- Call us with the information on your pump’s tag so we can confirm whether you have a 3406A, 3406B, or 3406C pump and talk through your symptoms.
- Ship the pump to us or drop it off. We tear it down, inspect it, and give you a firm quote before any work begins.
- We rebuild and bench-calibrate the pump, then return it ready to install, backed by our warranty.
Call 530-668-0818 for pricing and turnaround, or start your rebuild online → and we will walk you through shipping it in.
Why Valley Fuel Injection
Valley Fuel Injection & Turbo is a full-service, factory-certified diesel fuel injection shop in Woodland, California, serving truck owners, farmers, fleets, and other repair shops across the country. We have the tooling, the test equipment, and the certification to rebuild these pumps correctly, and we have been doing it long enough to have seen just about every 3406 fuel system failure there is. When a shop cannot fix it, they send it to us. Ship your pump from anywhere or visit us at our Woodland shop.
Not sure whether your problem is the pump itself or injection timing? On a 3406 the symptoms overlap more than most people expect, and a timing problem can look exactly like a tired pump. Read our injection pump timing symptoms guide before you pull the pump.
Frequently Asked Questions
How much does a CAT 3406 injection pump rebuild cost?
Most Caterpillar 3406 injection pump rebuilds run between $3,600 and $5,400, with a typical rebuild around $4,500. That is our real shop pricing for this pump, not a markup guess. Pumps with heavier internal wear, or that need a full set of plunger and barrel assemblies, a governor shaft, or a weight carrier, run toward the top of the range. Every rebuild is priced on your pump’s actual condition, so we give you a firm quote after teardown, before any work begins. Call 530-668-0818 for current pricing.
Do you rebuild the 3406E injection pump?
No, because it does not use one. This service covers the mechanical 3406A, 3406B, and 3406C, which use a cam-driven, scroll-type inline injection pump. The 3406E is a later electronic engine that fuels through electronic unit injectors, so there is no pump of this type on it to rebuild. If you are not sure which 3406 you have, call 530-668-0818 and we will sort it out with you.
Do I send you my pump, or do you have one in stock?
This is a rebuild service for your own core. You ship us your 3406 pump or bring it in, we rebuild and recalibrate it to the Caterpillar test plan, and we send it back matched to your engine. Rebuilding your core is usually faster and less expensive than hunting down a replacement pump for a mechanical 3406, and it keeps the pump set to your engine’s own rating instead of a generic average.
Can I ship my 3406 pump to you from out of state?
Yes. We rebuild 3406 pumps for customers nationwide. Remove the pump, pack it securely in a sturdy box with plenty of padding, and ship it to our Woodland, California shop. We tear it down, call you with a firm quote, and once you approve it we rebuild and bench-calibrate the pump and ship it back ready to install. You can also start your rebuild online and we will walk you through it.
What warranty comes with the rebuild?
Every pump we rebuild carries a 1-year warranty. Electrical and electronic components are warrantied for 30 days. We control every step of the rebuild in-house, from teardown to final bench calibration, which is why we can stand behind it. Clean, water-free fuel is essential to pump longevity, so we recommend fresh fuel filters at installation to protect your rebuild.
What parts get replaced in a 3406 pump rebuild?
Every 3406 rebuild starts with a complete teardown. From there we fit the correct plunger and barrel assemblies, single-helix or dual-helix depending on your pump, and service the camshaft and riser bearings, the governor shaft, the weight carrier in the correct early or late style, the check valves, and the tappets and spacers. A full gasket set, the 3406B/C pump mount kit, and a new finishing kit go in on assembly. The pump is then calibrated to the Caterpillar test plan on our bench.
How do I know which 3406 pump I have?
Read the tag on the pump and call us. The mechanical 3406 ran a long time and the pumps are not all the same inside: some use single-helix plunger and barrel assemblies, others use the dual-helix large-cam versions, and the governor weight carrier came in early and late styles. The 3406C shares the 3406B pump mount. We confirm exactly what you have during teardown and quote it from there, so you are not guessing at parts over the phone.
How long does a 3406 pump rebuild take?
Turnaround depends on our current shop schedule and parts availability for your specific pump. We give you an honest timeline when we quote the job. If your truck, genset, or boat is down and you need it back fast, tell us when you call 530-668-0818 and we will do our best to prioritize your rebuild.
Reviews
There are no reviews yet.