John Deere 4430 hydraulic pump

I lost power steering and brakes. I think it's the hydraulic pump. I think the part number is ar94661. Any advise or words of wisdom would be appreciated.

Check pump coupler.

Front pump will not draw oil up to or into it . It has to be pressure fed from the transmission pump .
When was the last time the filters were changed and the screen cleaned ? Type of hydraulic oil ?

Diagnose the problem properly first before spending big money on a pump that is likely not the problem. Pump drive splines and supply pressure are the usual suspects and poor supply can have several problems as the cause. Get a manual and test it after you understand the system.

What does it mean to "d stroke" the pump?

(quoted from post at 13:35:37 04/29/18) What does it mean to "d stroke" the pump?

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It's a closed-center system and when it comes up to operating pressure the stroke control valve on the front of the pump pressurizes the "crankcase" of the pump, holding the pistons outward so they don't take on a charge of oil, effectively stopping the pump from pumping oil/building further pressure.

There's a manual destroking attachment available for the pump to make cranking/starting the engine in cold weather easier, or even an electric version that destrokes it automatically during cranking.

If you intend on troubleshooting and repairing this yourself you ABSOLUTELY need the factory shop manual which has detailed information and troubleshooting charts. It is a complicated system, and (after you've verified the pump itself is actually turning) troubleshooting/diagnosis will begin at the REAR of the tractor, with the suction screen, transmission pump, and filter.

Don't even think about it an "aftermarket" manual, it will lack many/most detailed troubleshooting steps.

Get an original, and official copy, or get it on CD.

Typically, the copies of copies commonly sold omit color in their hydraulic flow diagrams, rendering everything in grayscale and making it USELESS.

Did the hydraulics die slowly or did you lose it all instantly? Any odd noises when it stopped? Piston-pumps like you have rarely go bad all at once. #1 make sure the pump is actually turning. There is a coupler that connects it to the crankshaft pulley and it sometimes either breaks or has the internal threads strip. That is the most common failure area. IF you are sure the pump is turning -and it died suddenly - I'd suspect a bad stroke-control valve . Or if you are lucky, it just has some debris holding it open. That main pump must have oil feeding it. Technically, no requirements for pressure but there has to be a free flow of it. If the main pump was starving for feed-oil - it should of made hammering noises and things should of gotten jerky before it all quit.

Check transmission drive shaft remove the top link bracket and remove the plug under it and pull out the little hex shaft and look about half way to see if it's rounded off where the trans pump runs

You are considerably smarter than the average person asking questions here . The usual question is “ I replaced the $$$ front pump and there are still no hydraulics, what is wrong ?