Hydraulic Pump AN272979 Fits for John Deere Cotton Picker 9976 9986 9996 af37e686 a000 487e 9fef 1b1bc979b885.jpg

AN272979 Hydraulic Pump for John Deere Cotton Picker 9976 9986 9996

A hydraulic pump for John Deere 6090, 555, 555A and 555B engine crawler loaders, part number AT74412. The pump supplies the oil flow and pressure the machine hydraulics work with. It also appears under part number AT41452.

Category: Hydraulic Pump Assembly

Description
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AT74412 Hydraulic Pump is a replacement hydraulic pump for John Deere engine crawler loaders, including 6090, 555, 555A, 555B. The main hydraulic pump converts engine power into pressurized oil flow. Supplied by LIONKITS as new oem.

AT74412 Hydraulic Pump Specifications

Product Type: Hydraulic Pump
Part Number: AT74412, AT41452
Compatible Brand: John Deere
Machine Type: Engine Crawler Loader
Condition: New OEM
Country of Origin: China

John Deere Models Compatible with the AT74412 Hydraulic Pump

John Deere Motor Grader: 670B, 672B, 770B, 770BH, 772B, 772BH
John Deere Crawler Loader: 555, 555A, 555B
John Deere Trackde Feller Buncher: 803M, 803MH, 853M, 853MH, 859M, 859MH
John Deere Engine: 6090

Your model is not listed? Contact LIONKITS via live chat or email with your machine model and nameplate photo, and we will confirm compatibility.

What Does a Hydraulic Pump Do?

The main hydraulic pump converts engine power into pressurized oil flow. That oil moves the boom, arm, bucket, swing and travel functions, so every machine movement depends on it. Because it takes the most punishment, it is usually the first major hydraulic component to wear out.

Signs the Part Needs Replacing

Slow or weak movement on all functions: when everything is slow at once, not just one circuit, the pump is the most likely source.
Whining, knocking or grinding noise: internal wear or cavitation, especially on start-up or when the oil is cold.
Hydraulic oil running hot: internal bypass leakage turns pressure into heat.
Metal particles in the filter or case drain: a failing pump sheds metal and pushes out more case drain flow.
Erratic or spongy movement, foamy oil: air entering the suction line, or aeration, upsets pump flow.

These symptoms overlap with clogged filters, low oil, air in the suction line and worn valves, so check the filters and oil level before replacing the part.

How to Order and Install the AT74412 Hydraulic Pump

Confirm your machine model, the part number and the pump model on your existing pump before ordering.
Send a photo of the old pump or the nameplate if you are not sure; LIONKITS will confirm fitment for you.
Change the hydraulic oil and the return filters before fitting the new pump; a new pump installed in contaminated oil will fail early.
If the old pump failed internally and shed metal, flush the tank, hoses and oil cooler and inspect the control valve and motors for contamination.
Fill the pump case with clean hydraulic oil and prime the pump as the service manual specifies before the first start.
Check the suction line, strainer and fittings for air leaks, and tighten bolts to the specified torque.
Run the machine at low speed first, then check pressure, noise and leaks.

Frequently Asked Questions

What is the AT74412 Hydraulic Pump?

The AT74412 Hydraulic Pump is a replacement hydraulic pump for John Deere engine crawler loaders, supplied as new oem under part numbers AT74412, AT41452.

Which John Deere models does the AT74412 Hydraulic Pump fit?

It is listed for 6090, 555, 555A, 555B and other models in the compatibility list above. If you are unsure, send your machine nameplate to LIONKITS for confirmation.

How do I know my hydraulic pump is failing?

Typical signs are slow or weak movement on all functions, whining or knocking noise, hot hydraulic oil, metal particles in the filter or case drain and erratic or spongy movement.