Changing Spool Valve from double acting to single

Hill Bill

Hi,
would anybody know how to change a double acting spool valve to single acting on a New Holland 5635?

I can use the float position to lower a single acting ram but it’s not ideal.

I have the owners manual but it’s very vague, the diagram it shows is vague & doesn’t match what’s actually on the block.
There is a flat-headed screw with a nut but it refers to this elsewhere in the manual as being for adjusting the indent pressure. This is fairly stiff so I want to be sure before trying it.

Thanks in advance.

minerleague

Hill Bill wrote: »

Hi,
would anybody know how to change a double acting spool valve to single acting on a New Holland 5635?

I can use the float position to lower a single acting ram but it’s not ideal.

I have the owners manual but it’s very vague, the diagram it shows is vague & doesn’t match what’s actually on the block.
There is a flat-headed screw with a nut but it refers to this elsewhere in the manual as being for adjusting the indent pressure. This is fairly stiff so I want to be sure before trying it.

Thanks in advance.

on older mf tractors there is a screw under the spool valves where u attach hydraulic pipes (dont know if this helps or not)

mad-for-tar

Hill Bill wrote: »

Hi,
would anybody know how to change a double acting spool valve to single acting on a New Holland 5635?

I can use the float position to lower a single acting ram but it’s not ideal.

I have the owners manual but it’s very vague, the diagram it shows is vague & doesn’t match what’s actually on the block.
There is a flat-headed screw with a nut but it refers to this elsewhere in the manual as being for adjusting the indent pressure. This is fairly stiff so I want to be sure before trying it.

Thanks in advance.

I’d say what you have already are the De-luxe valves as they call them, look something similar to what was in a 40 series. There’s no switchover on them for single or double acting, they are double acting as they are.
Only when they went to TL-A series you got option of Kontak/Commercial Hydraulics slices that had changeover option on them (similar to 300 Series Massey etc).

Later book suggests when using with single acting cylinders you’d use lower and float positions of the lever and pipe the extend port into free flow return to allow quick exhaustion of oil from single acting cylinder. Not ideal but it was a factory offered workaround for them.

The adjustment you are talking about is the setup for kick out pressure, the pressure at which the lever is kicked into neutral at end of stroke of a ram etc.
So as you are, you already have DA, cannot change to SA and if you have to, use lower position to open the cylinder and float position to drop it.

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Hill Bill

That makes sense now why I couldn’t seem to find the changeover screw, it’s not there!

Seems strange that they didn’t give this option, I’ll just have to carry on as I am so.

Thanks for the detailed reply Mad-for-tar.