two horser 11 #1 Posted March 18, 2023 Have a D200 will move in forward real slow, will move in reverse at full speed. looses power in forward. causes ? 2 Share this post Link to post Share on other sites
pfrederi 17,864 #2 Posted March 18, 2023 Quick Guess is a bad acceleration valve spring. Download this manual it has an excellent trouble shooting guide and also shows how to make repairs... 1 Share this post Link to post Share on other sites
daveoman1966 3,758 #3 Posted March 18, 2023 (edited) The D-200 is at least 40 yrs old...thing wear out. The surest way to restore power in either direction is to do a complete overhaul of the hyd PUMP (at the engine) ---and--- the hyd MOTOR (at the trans gear box). To overhaul one and not the other will give less than optimum results as the internals of each have many soft brass components that have been wearing for 40 YEARS. When these brass parts become worn and/or scarred, oil pressure escapes thru those scars, resulting in low pressure, leading to loss of power. I have prepared an overhaul procedure, with pics, that will guide you thru the process. The most difficult part is removing the hyd PUMP from the engine. Here is my self-made the .pdf file: You will need a GASKET KIT as well... which includes O-rings and such. Me thinks the Red Square vendor WHEELPARTS AND MORE will have these. If not, try here: LJ Fluid Power at 269-623-4150 SUNDSTRAND Piston-Piston PUMP & MOTOR Refurb.pdf Edited March 18, 2023 by daveoman1966 1 Share this post Link to post Share on other sites
