The Forestry Forum

My john deere 540 has numerous hydraulic leaks.. small screw on top of hydro pump... 2 top fitting on tranny under hood,,,do those take normal orings or rubber/copper washers or a certain thing? others as well.. some seems to even leak without the machine running.. is this normal? for the machine to have pressure builtup even when not running or should i look at a certain part causing the buildup?
this is our first deere so all new to me

 On the hydraulic pump leak, if you mean the destroke screw which has either a 1/2 " hex on top or a roll pin handle, they are designed to be backseated when all the way up. Like an oxygen tank valve is designed to be backseated when full open. That should take care of that leak. 
  Almost all fittings that Deere uses for hydraulics are o-ring of one sort or another. If there is a jam nut tight against the housing, there is an o-ring under the washer for sure. They are a smaller section diameter, but a commonly enough used size that should be readily available. 
  Here's a link to Deere's online parts look up: https://partscatalog.deere.com/jdrc/ (https://partscatalog.deere.com/jdrc/)
The new parts catalog sorta sucks until you get used to it, and then it still does :(. It doesn't show detail like the old setup did, and navigation is weird, but all the information you need is there--------somewhere.

Thanks Oliver

I  might have mislead you on the destroke valve. The older screw with the roll pin handle does backseat. The one with the hex head has an o-ring and back-up ring on it, and you have to take the valve out of the pump to remove a snap ring to get it apart. As shown as #15 in this parts page: 
HYDRAULIC PUMP STROKE CONTROL VALVE 50 CM3 (3 IN.3) (REPLACEMENT PUMP WITH SERIAL PLATE) (SKIDDER SERIAL NO. 405036 - ) (GRAPPLE SKIDDER SERIAL NO. 403202 - ) [02K01] - 2160-14