Six way blade seems to hydraulically lock up.

[billtabbert]

Hi!
I have around a 1977 350B. When I try to use any function up, tilt, or angle on the six way blade it will only go so far, then stop. It feels as though it locks up hydraulically. If I use another function, it will then allow the first to continue. Let me step you through this..
1.) Lift blade up, and it stops 1/4 of the way and will NOT go up further.
2.) Perform any other function like angle and it will stop a 1/4 way through.
3.) Now you can continue raising the blade to around a 1/2 way up.
4.) repeat steps 2 to 3 until desired position is achieved...

This is the case with all movements except down.. Any idea where to start guys?
Bill

[RMilanese]

not sure if the 350 6-way is the same at the 450 loader (suspect its different enough to not be useful) or I'd scan my manual for you, but my advice would be get the tech manual and study the ports and fluid paths... my guess is there is a bypass leak somewhere in the valve that is locking motion until another function relieves the common bypass pressure... just a logical assumption based on my limited understanding of how a hydro valve block works that one way or another that valve block needs a rebuild...In fact, I'd be pretty certain that's where the problem is as long as you haven't messed with any of the hoses and your pressures seem pretty normal otherwise.

[LeonardL]

I agree and you are spot on with your assumptions on this issue. Hydraulics is all Flow and Control. I suspect you either have a spool bypassing or a broken return spring or a broken spool that is getting caught in the direction you first put it in and not returning until you put pressure on it from a different direction. Your control valve is going to be the issue as was just previously stated. Some of the older 450s did have a very similar control valve and the hydraulics were just about identical.
Your issue could also be in the control valve lever linkages as well. If they are worn bad enough they will cause the valve to hang in position until you move it to something else. Make sure the linkages are all okay and working like they should.