Water Pump 6684225 6653941 | Cross-Reference for Kubota D1402

Cross-reference verified — bolt pattern and coolant port orientation checked against Kubota D1402 blocks before dispatch.

Technical Specifications

Application Suitability

Superseded Numbers and Variant Traps That Keep Machines Down

A single water pump designation can cover multiple physical builds — and copying a number from a listing is not fitment verification.

When a Bobcat S175 comes into a workshop with a failed coolant pump, the plate might read 6684225 or 6653941, and both are listed in the same cross-reference tables across dozens of aftermarket sources [NEED_CITE: aftermarket parts cross-reference accuracy in compact equipment]. But those two numbers do not always describe an interchangeable unit on every Kubota D1402 variant. Some engine serial ranges moved the coolant outlet to a different clock position, and some changed the mounting flange from a four-bolt to a different spacing. I have watched a technician spend half a day trying to force-fit a pump that "matched the number" while the port pointed directly into the engine mount.

Fitment Scope Across the Bobcat Compact Loader Range

The Kubota D1402 engine sits at the center of this application range, appearing in machines from the early 643 compact loader through the current S185 skid steer. The Water Pump for Bobcat S150 S185 / Kubota D1402 cross reference covers machines built across different production runs, and that span is exactly where variant differences emerge. Earlier builds may carry a different casting mark on the block, and the pump housing interface changed accordingly.

Interface Verification Points That Separate a Fit from a Return

Before committing to an order, four physical checkpoints tell you whether this pump belongs on your machine. First, measure the bolt hole spacing on the mounting flange — this must match the removed unit, not just the catalog illustration. Second, confirm the coolant outlet port orientation by clock position relative to the mounting face [NEED_CITE: coolant system port alignment standards for compact diesel engines]. Third, verify the pulley or impeller shaft interface matches the drive arrangement on your specific engine build. Fourth, if the machine has had a prior engine swap or rebuild, check whether the replacement block matches the original equipment configuration — swapped engines are the most common source of fitment errors in the field.

Reading the Spec Sheet for What It Means on the Block

This pump moves coolant through a Kubota D1402 block that operates under continuous high-load conditions in skid steer and loader applications. The impeller design governs flow volume at operating RPM, and insufficient flow shows up as creeping temperature rise under sustained digging or travel cycles rather than immediate overheating. The mounting flange must seal against the block face without distortion — a warped housing or out-of-tolerance bolt pattern creates a slow weep that only becomes visible after the machine has been running under load. The ISO-certified production standard applied here means dimensional checks on these interfaces are performed before the unit leaves the facility, rather than relying on the installer to discover a mismatch on the shop floor.

What a Wrong-Fit Delivery Actually Costs

The immediate cost is not the pump itself — it is the machine sitting in the bay while a replacement ships. A skid steer that was supposed to return to a job site on Monday is still on blocks on Thursday because the port orientation was wrong and no local stock carries the correct variant. For a fleet operation, this compounds: a rental unit that cannot go out is lost revenue every day it sits [NEED_CITE: equipment downtime cost impact in compact loader rental fleets]. The second failure mode is subtler — a pump that bolts on but has the wrong impeller specification runs hotter than the original, and the operator blames the thermostat or the radiator for months before tracing the problem back to the replacement pump.

Why Sourcing Here Removes Fitment Guesswork

Production on selected lines runs in our own facility, while the remainder is sourced from ISO-certified manufacturing partners — both carry the same quality control and warranty terms, so there is no quality tier to navigate. Eight categories of parts are available under one account, meaning a complete cooling system refresh ships as a single consignment. The minimum order is one piece, which matters when you need a single emergency replacement or a sample to confirm fit before committing a fleet order. We identify parts from a part number, machine model, photograph, or nameplate image — useful when the plate on a Bobcat 753 is painted over or missing entirely. Cross-reference verification covers superseded and alternate numbers, including cases where 6684225 and 6653941 apply differently depending on the engine serial range. A sample unit is available for physical trial fit before a bulk purchase decision, and our technical team confirms compatibility and variant selection before dispatch.

Documentation & Verification

• Commercial invoice and packing list with line-item part numbers for customs clearance
• Fitment and cross-reference sheet noting which number applies to your engine serial (reference only)
• Dimensional check record covering bolt spacing and port orientation before dispatch
• Warranty terms document specifying coverage period against manufacturing defects
• Packing photographs showing unit condition and protective wrapping before crate closure
• HS code and export documentation support for destination-country import requirements

Fitment Check Before Installation

• Compare bolt hole spacing on the new pump against the removed unit before beginning installation
• Verify coolant port clock position matches the hose routing on your specific Kubota D1402 build
• Check impeller shaft interface against the existing drive pulley or coupling arrangement
• If the engine has been rebuilt or swapped, confirm block casting matches the original equipment spec
• Perform a dry-fit without sealant first to confirm flange alignment and hose reach
• Document any dimensional discrepancy and contact technical support before proceeding further

Requesting a Fitment Confirmation

Send the machine model and serial number from the frame plate, or a clear photograph of the existing pump showing the mounting face and port positions. If the nameplate is missing or unreadable, a photo of the engine block casting mark and the old pump alongside a ruler allows identification by physical measurement. We return a confirmed cross-reference and variant recommendation before any order is placed.

Frequently Asked Questions

Q: How do I confirm this water pump fits my specific Bobcat loader serial number? A: Provide the machine model and the serial number from the frame identification plate. We cross-reference the applicable engine serial range against both 6684225 and 6653941 to determine which variant matches your build, then confirm bolt pattern, port orientation, and shaft interface before you commit to an order.

Q: Both 6684225 and 6653941 are listed — which one applies to my machine? A: These two numbers cover different production runs of the Kubota D1402 engine, and they are not always physically interchangeable. The correct number depends on your engine serial range and the specific casting variant. Share your machine serial or a photo of the existing pump and we confirm which designation applies.

Q: My old pump has a different number not listed here — can you cross-reference it? A: Yes. Send the number stamped or labeled on your existing unit along with a photograph if possible. Many pump castings carry manufacturer stamps that differ from the equipment brand reference numbers. We trace the cross-reference through superseded and alternate designations to confirm whether this unit matches.

Q: I only have the machine model, the nameplate is gone — is that enough to identify the right pump? A: A machine model narrows the range but may not resolve the variant. If the nameplate is missing, send a photograph of the engine block casting mark and the old pump from multiple angles. Physical measurement of the bolt pattern and port position often confirms the correct unit when paper identification is unavailable.

Q: Can I get a sample to test fitment before ordering for my full fleet? A: Yes. We supply a single sample unit for physical trial fit on one machine before you commit to a bulk order. This confirms bolt pattern, port alignment, and shaft interface on your actual equipment, removing fitment uncertainty across the rest of the fleet.