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Join Date: Jul 2007
Location: Carroll County, MD
Re: john deere hydraulic pump issues
I can't say I have ever seen one of these crack. The valve in the bore witht the screen is the crankcase outlet valve. That is #11 & 13 in TxJim's diagram. I am wondering if that valve seized up and caused too much internal pressure. Does the two parts of the valve slide freely in and out of each other? If they are free, then maybe it was never adjusted properly. It is adjustable with shims, #19. The only way to adjust it properly is with a special tool that your dealer should have. I can't remember the tool number off the top of my head for sure, but it may be JDH15c. If all that is correct, then the stroke ccontrol valve in the other bore might have been adjusted too high as TxJim suggested, the standby pressure should be set to 2200 - 2250 psi adjusted by screw #37.