Caterpillar 3P-6816 is the hydraulic gear pump in a black cast iron body with a round mounting flange, splined drive shaft and a flanged outlet elbow. It is used on Caterpillar D6C to D6G2 dozers. This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
Technical properties & sizes
Specifications
| Part Type |
Hydraulic Gear Pump |
| Replaces |
Caterpillar 3P-6816 |
| Machine |
Caterpillar D6C, D6D, D6E, D6G, D6G2 dozers |
| Engine |
Caterpillar 3306 |
| Fits |
Caterpillar D6C, D6D, D6E, D6G and D6G2 dozers (3306 engine) |
| Condition |
New, aftermarket |
| Stat. HS-Code |
841360 |
| Country of Manufacture |
China |
Compatibility
Caterpillar machines
Caterpillar D6C, D6D, D6E, D6G and D6G2 dozers (3306 engine)
Check the part number on your old unit before ordering.
Part numbers
| Caterpillar Part No.(SPM Part No.)
|
Fits |
|
3P-6816(SPM-HEP-5074)
|
Caterpillar D6C, D6D, D6E, D6G and D6G2 dozers (3306 engine) |
|
3P6816(SPM-HEP-5074)
|
Caterpillar D6C, D6D, D6E, D6G and D6G2 dozers (3306 engine) |
Applications & use cases
Slow or weak hydraulics
A worn pump loses flow and pressure: functions slow down, especially when the oil is hot.
Noise
Whining or knocking from the pump points to worn gears or pistons, or cavitation from a blocked suction line.
Contamination
Metal in the filter or oil means the pump is wearing. Replace it before debris damages valves and motors.
Fitting tips
Flush the system, change the oil and filters, fill the pump case before starting, and run at low speed first.
Price beat guarantee
We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:
| Seller |
Price |
Checked |
| eBay, aftermarket seller |
USD 283.61 |
2 Nov 2026 |
| Broken Tractor |
USD 390.00 |
2 Nov 2026 |
| Kudu Parts |
USD 460.00 |
2 Nov 2026 |
| FridayParts |
USD 504.01 |
2 Nov 2026 |
| SINOCMP |
USD 529.00 |
2 Nov 2026 |
| Spare Part Mart |
USD 226.89 |
Today |
Our price of USD 226.89 is 20% to 57% less than these sellers.
Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.
Frequently asked questions
Will it fit my Caterpillar D6C?
Yes, it was made for the Caterpillar D6C, and 4 more listed under compatible equipment. Check the old hydraulic pump is marked 3P-6816 or one of the cross references, because makers change parts between serial ranges.
How often should I replace the hydraulic pump on my Caterpillar D6C?
On the Caterpillar D6C, often 5,000 to 10,000 hours with clean fluid, much less with dirt or air in the system. It is usually changed on condition, not by hours.
What are the signs the hydraulic pump needs replacing?
Leaks from the seal or weep hole, noise or whining, overheating, or falling pressure or flow under load.
Should I prime it before starting?
Yes. Fill the pump and its suction line with clean fluid before the first start. Running it dry, even for a few seconds, can score it.
Why did the old pump fail?
Most failures come from contamination, cavitation from a restricted inlet, or running low on fluid. Check the inlet and the fluid before fitting the new hydraulic pump.
Is this a genuine Caterpillar 3P-6816?
No. It is an aftermarket hydraulic pump made to replace the Caterpillar 3P-6816. It is not made by the original manufacturer; the number only shows what it replaces.