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Cummins 3635783 is the cast iron gear driven coolant pump with a splined drive shaft, a four bolt mounting flange and a round outlet. It is used on Cummins K38 and KTA38 engines. This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.
The same part is also sold as Cummins 3647029 and Cummins 3050443.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
| Part Type | Water Pump |
| Replaces | Cummins 3635783 |
| Engine | Cummins K38, KTA38 |
| Drive | Splined shaft, gear driven |
| Cross references | Cummins 3647029, Cummins 3050443 |
| Fits | Cummins K38 and KTA38 engines |
| Condition | New, aftermarket |
| Stat. HS-Code | 841330 |
| Country of Manufacture | China |
Cummins machines
Check the part number on your old unit before ordering.
| Cummins Part No.(SPM Part No.) | Fits |
|---|---|
| 3635783(SPM-HEP-4672) | Cummins K38 and KTA38 engines |
| 3647029(SPM-HEP-4672) | Cummins K38 and KTA38 engines |
| 3050443(SPM-HEP-4672) | Cummins K38 and KTA38 engines |
What it does
It circulates coolant through the block, head and radiator. A worn seal or bearing lets coolant out and the engine overheat.
Where it is used
Made for the Cummins K38 and KTA38 engines. The full list is in the tables above.
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 652.52 | 31 Oct 2026 |
| SINOCMP | USD 699.00 | 31 Oct 2026 |
| FridayParts | USD 794.84 | 31 Oct 2026 |
| Dale's Super Store (Freedom Injection) | USD 1,100.95 | 31 Oct 2026 |
| Spare Part Mart | USD 526.58 | Today |
Our price of USD 526.58 is 19% to 52% 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.
Yes, it was made for the Cummins K38, and 1 more listed under compatible equipment. Check the old water pump is marked 3635783 or one of the cross references, because makers change parts between serial ranges.
On the Cummins K38, 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.
Leaks from the seal or weep hole, noise or whining, overheating, or falling pressure or flow under load.
Clean them right back to metal and fit the new gasket or O-ring dry, unless the engine manual calls for sealant.
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 water pump.
No. It is an aftermarket water pump made to replace the Cummins 3635783. It is not made by the original manufacturer; the number only shows what it replaces.
Live rates for the quantity selected, delivered to your door. Confirmed at checkout.
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