John Deere and the Roosa Master rotary pump grew up together. From the 4010 of the early 1960s to the PowerTech engines in later generations of loaders and tractors, green machines have leaned on Roosa Master and Stanadyne pumps, with Denso common-rail pumps joining the family on modern common-rail engines.
This page matches your tractor, combine, backhoe or dozer to its pump, then explains each family in plain shop language.
We can help identify these systems and discuss service options, from a 4020 that has worked every season since the Johnson administration to a late-model PowerTech that runs a crew’s whole day.
Which Pump Is on My John Deere?
| Era | Models | Injection pump | Number clues |
|---|---|---|---|
| Early 1960s | 4010 tractor | Roosa Master DBG | DBGVC631-, DBGFC631- |
| 1960s-1970s | 4000, 4020, 4030, 4320 and 2630 tractors; 4400 combine | Roosa Master JDB | JDB633, JDB635 |
| 1970s | 4230 tractor | Roosa Master DM4 | DM4629- |
| 1960s and earlier | Older tractors, combines and industrial units such as the JD 400 backhoe | Roosa Master CBC and CDC | Read the plate |
| 3029, 4039, 4045 and 6068 engines | Stanadyne DB2 and Stanadyne DB4 | DB2335-, DB2435-, DB4629-, DB4429-, DB4329- | |
| PowerTech 4045 and 6068 Level 12: 6615-7720 tractors, 310 and 410 backhoes, 450J-650J dozers | Stanadyne DE10 | DE2635- | |
| Later PowerTech and the 9.0L | Denso HP3 and Denso HP4 | 294000-, 294050- |
Don’t see your model? Deere has used other pumps over the years. Send us the number off the pump plate and we will identify it.
Roosa Master JDB, DBG and DM: The Vintage Green Lineup
Roosa Master pumps are rotary distributor pumps. Instead of one plunger per cylinder, a single spinning rotor with opposed plungers pressurizes fuel and deals it out to every cylinder in turn. One heart pumping for the whole engine, not six little hearts in a row.
The JDB is the one most owners meet, on the 4020 and its relatives. The DBG on the 4010, the DM4 on the 4230 and the older CBC and CDC pumps do not have their own pages yet, so ship them in and we will test them. See our Stanadyne and Roosa Master page for the full family.
Did You Know? The Roosa Master pump arrived in 1952, the DB line followed in 1958 and the Stanadyne name came along in 1970. Plenty of owners still type it as one word: Roosamaster.
Bench Notes: Vintage pumps that sat for years often come in with varnish from stale fuel, corrosion from water and parts stuck in place. Rust can hide inside a pump that looks fine outside, which is why a teardown inspection matters.
Stanadyne DB2 and DB4: Workhorses of the 3029 to 6068
The DB2 and the higher-output DB4 carry the Roosa Master idea forward on Deere’s 3029, 4039, 4045 and 6068 engines. They are mechanical, durable and easy to live with, and they keep a lot of tractors, loaders and irrigation power units running. The DB4 also turns up on Perkins 1004 and 1006 engines in some Deere backhoes; see our Perkins and Cat page.
Stanadyne DE10: Electronics Arrive
The DE10 is an electronic rotary pump used on Level 12 PowerTech 4045 and 6068 engines. Fuel and timing respond to the engine controller instead of springs and weights alone, which sharpens performance and emissions but adds electronics to diagnose. Numbers start DE2635-.
Shop Talk: A rotary or distributor pump uses one pumping element to serve every cylinder. An inline pump uses one plunger per cylinder, lined up in a row.
Denso HP3 and HP4: Common Rail on Late PowerTech
Later PowerTech engines and the 9.0L moved to Denso common-rail supply pumps. The HP3 has two plungers and the HP4 has three; both keep a rail full at very high pressure while the injectors handle timing. Like all common-rail pumps, they hate water and dirt.
Common John Deere Pump Problems
- Leaks. Throttle shaft and cover seals on vintage and DB-series pumps. See our injection pump leaks guide.
- Hard starts and white smoke. Timing, wear or air in the system. Our hard start and smoke guide helps narrow it down.
- Surging or hunting. Worn governor parts.
- Stuck after storage. Varnish and corrosion from sitting.
- Codes on newer machines. DE10 electronics or common-rail pressure faults.
How to Tell What You Have
Find the plate on the pump. Roosa Master and Stanadyne plates carry a model code such as JDB633, DB4629-, or DE2635-, and many also show a John Deere part number. Note the tractor or machine serial number too.
Owner’s Tip: Before you pull the pump, photograph the timing marks and line routing and write down every number on the plate. Check the fuel filters and sediment bowl first; a clogged filter can fake a bad pump.
Ship It Right: Drain the pump, cap every fitting and pack it so it cannot shift. Put your machine model and serial number on the paperwork.
Questions about John Deere Injection Pump Repair
My 4020 pump leaks. Rebuild or replace?
A leaking JDB is usually a strong rebuild candidate, but the inside decides. Our rebuild vs reman vs new guide walks through the choice.
Do you work on electronic DE10 and Denso pumps?
Yes. We test and repair them on the bench.
My pump sat for twenty years. Is it worth rebuilding?
Often, yes. An evaluation tells you what it needs before you commit to a full rebuild.
What determines whether a John Deere pump can be rebuilt?
For John Deere Injection Pump Repair, the available path follows what inspection actually finds—not a universal rebuild recipe. DCT reviews the engine generation, original equipment, failure history and part number, whether the correct service parts and calibration information are available, and which work the customer chooses to authorize. Any exchange option is confirmed for the exact part rather than assumed from the family name. Explore how repair options are compared.
Deere built these machines to outlast their first owners. Help yours make it to the next one. Start a Mail-In Repair or request a repair evaluation.
See the corresponding pump-family guides
- Read the STANADYNE DB2 family guide
- Read the STANADYNE DB4 family guide
- Read the STANADYNE DE family guide
- Read the DENSO HP3 family guide