1969 4000 diesel

[Caliche]

My rear attachment and front end loader bounce whenever my rear lift is fully raised . Lower the rear lift slightly and the bouncing ceases. Front end loader position has no affect. Any ideas ?
 

[Tom in Mo.]

Your tractor is a teeter totter. The 3 point bouncing is making the loader bounce.
 

[Destroked 450]

A worn piston seal in the 3 point will cause it to bounce, the loader bounce could be caused by a rocking motion of the tractor from the 3 point
 

[sotxbill]

No. your tractor has the hiccups.
 

[Caliche]

Are you saying the hiccup valve needs replacing?
 

[Caliche]

Are you saying the hiccup valve needs replacing?
 

[Caliche]

Whats the fix ?
 

[Sean in PA]

The cause is that it is leaking internally as Destroked 450 said. The fluid leaks past the piston seal and the arms lower a little bit, but the position control senses the drop and raises it again, and that repeats over and over. Some folks call that the hiccups. If the implement on the 3 point arms is heavy, then that repeated up and down weight transfer will cause the tractor to rock, and as a result the front end loader will bob up-and-down as well.

The fix is to remove the top cover and replace the seal on the piston. You should get a service manual and follow that to replace all of the seals and o-rings while you're in there, as well as follow the steps to adjust the linkages, as you don't want to have to remove the top cover again in a few months.
 

[Caliche]

Thanks Sean for the guidance. Ill relay this to my mechanic.