Ford 1510 Hydraulics - Tractor Shudders

[xring600]

I purchased a Ford 1510 Tractor a few weeks ago and everything is going good except for the hydraulics lift. When I raise the back everything is ok. However if I lower it some and stop the hydraulic system strains to keep it at that level. It will drop just a bit and then raise back to that level continuously.

I changed the fluid as it was very milky along with the filter which is a NH brand filter. Problem is still there. Fluid levels are good. No leaks anywhere.

Any suggestions?

 

[xring600]

I found a document that stated the hydraulic fluid should be checked with the dipstick not screwed down. Thought that the fluid could be low since I have been checking it like your car with the stick seated in the threads. So I went out this morning 1st thing, checked the fluid with the stick not screwed in, and it was a little low but registered almost 3/4 up the checkered area of the stick. So that's not it either. Still searching.

 

[square1]

Take a look at page 13 (starts ~ post 123) of this thread
http://www.tractorbynet.com/forums/...-14.html?highlight=ford+1700+lift+seal+piston

 

[xring600]

Take a look at page 13 (starts ~ post 123) of this thread
http://www.tractorbynet.com/forums/...-14.html?highlight=ford+1700+lift+seal+piston

Thanks for the reply. The problem was the seal ring on the piston located in the lift arm housing. Our tractor supply store did not have it and we ended up using a couple of O rings to do the job. Working good now. Part number 25 in the picture attached.