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SPM-HEP-5224 is the HEUI injector: the yellow solenoid valve on top with its connector, the hold down flange and the nozzle body with the sealing rings. It is used on Caterpillar 3126B, 3126E and C7 engines. This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.
It replaces Caterpillar 222-5966 and Caterpillar 10R-0781.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
| Part Type | Fuel Injector |
| Replaces | Caterpillar 222-5966 |
| Type | HEUI injector |
| Engine | Caterpillar 3126B, 3126E, C7 |
| Cross references | Caterpillar 10R-0781 |
| Fits | Caterpillar machines and trucks with the 3126B, 3126E and C7 engines |
| Condition | New, aftermarket |
| Stat. HS-Code | 840999 |
| Country of Manufacture | China |
Caterpillar machines
Check the part number on your old unit before ordering.
| Caterpillar Part No.(SPM Part No.) | Fits |
|---|---|
| 222-5966(SPM-HEP-5224) | Caterpillar machines and trucks with the 3126B, 3126E and C7 engines |
| 10R-0781(SPM-HEP-5224) | Caterpillar machines and trucks with the 3126B, 3126E and C7 engines |
What it does
It sprays a metered charge of fuel into the cylinder at the right moment. Spray pattern and opening pressure decide how cleanly the engine burns its fuel.
Where it is used
Made for the Caterpillar machines and trucks with the 3126B, 3126E and C7 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 (3 aftermarket sellers) | USD 351.12 to 352.12 | 3 Nov 2026 |
| SINOCMP | USD 359.00 | 3 Nov 2026 |
| Spare Part Mart | USD 280.90 | Today |
Our price of USD 280.90 is 20% to 22% 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 is a direct replacement for the Caterpillar 222-5966 with the same fitting.
Often 5,000 to 10,000 hours, but much less on poor or wet fuel. Injectors are usually changed when they fail a test, not by hours.
Black or white smoke, a misfire or knock on one cylinder, hard starting, higher fuel use, or a high return leak or balance rate on test.
Run a return leak test or read the injector balance rates with a diagnostic tool. On older mechanical engines, cracking each pipe in turn at idle shows which cylinder changes least.
Not always. If the others pass a return leak or balance test, one can be changed. Where they are all high hours, a full set keeps the cylinders even.
No. It is an aftermarket fuel injector made to replace the Caterpillar 222-5966. 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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