What is a 171 Hydraulic Control and how do I tell if my D7E has it? The transmission oil drain procedure is different for ones with and without. The one with it has 3 more gallons of oil.
Thanks!

The 171 Hydraulic Control consists of a fender mounted external (foot operated) control valve and a hydraulic pump. The control is used to operate a hydraulic blade tilt cylinder. The vane pump is mounted on the rear power take-off housing of the engine and is driven by the rear power take-off idler gear. The oil for the hydraulic control system is supplied from the tractor transmission and is cooled and filtered by the transmission oil system.

Go to the library and look at the D7E 16 page brochure I just put there yesterday. It has pictures of the all the hydraulic systems available for your tractor.
Craig

thanks guys! mine is a 173. i had drained all the oil that i could find plugs for and then it occurred to me that if mine is a 171 i should have drained the hydraulic with the motor running first.