Aux hydraulic response time

[Tazza]

I got some hoses to hook up my 4 in 1 on a 753 i just got, just how fast should the aux hydraulic buttons respond? I have found that if i press the button and open the bucket then release it doesn't stop instantly, it still creeps then stops. Same if i press the button and release it, it won't stop instantly its like its sticky or has a delay in releasing the coil. Does this sound normal at all? I'm kind of new to push button aux controls. It is an early 753, so i don't know if its normal for the "older" machines to do this or not.
Any ideas?

 

[thetool]

Hey Tazza-
The electrical part of the system is of course practically instantaneous.
The coils on the valve operate pilot valves on either side of the aux control spool. The spool is centered by a springs. If the springs are weak, it may be slow to stop moving.
If it is slow to start and stop, you may have a pressure problem. The aux pilot pressure is the charge pressure, controlled by relief in the hydrostatic pump. It may be low, just in the range to keep from producing a code or lighting a warning lamp, but slow down your aux. Low pressure can be from a bad pump and/or relief poppet. This is more likely the problem if it acts okay at high rpm, but performs increasingly poorly as you back off on the throttle.
But with the age of the machine and in my experience, it may be one or both aux valve stems, or the guts under the aux coils on the valve. They have little screens on them you can see when you pull them. There is a small bleed orifice in there that you can't see, but if this gets plugged, it restricts both the flow to activate and the bleed-off to let it center.
Also check to make sure your aux spool is sliding freely in the valve body, and the condition of the centering springs.
Good Luck

 

[Tazza]

Hey Tazza-
The electrical part of the system is of course practically instantaneous.
The coils on the valve operate pilot valves on either side of the aux control spool. The spool is centered by a springs. If the springs are weak, it may be slow to stop moving.
If it is slow to start and stop, you may have a pressure problem. The aux pilot pressure is the charge pressure, controlled by relief in the hydrostatic pump. It may be low, just in the range to keep from producing a code or lighting a warning lamp, but slow down your aux. Low pressure can be from a bad pump and/or relief poppet. This is more likely the problem if it acts okay at high rpm, but performs increasingly poorly as you back off on the throttle.
But with the age of the machine and in my experience, it may be one or both aux valve stems, or the guts under the aux coils on the valve. They have little screens on them you can see when you pull them. There is a small bleed orifice in there that you can't see, but if this gets plugged, it restricts both the flow to activate and the bleed-off to let it center.
Also check to make sure your aux spool is sliding freely in the valve body, and the condition of the centering springs.
Good Luck

Thanks for the info, i think i should check my charge pressure as i still have that odd noise, i just need to find the plug that its hiding behind. I never knew about the bleed holes.... With the state of the motor seals it really is possible that is my problem, i should have taken a picture, they were like powder! well what was left of them was.