Hydraulic pistons not working right

When it is cold, you get what you get.
When was the last time you lubed/slip plated your sliders?
How about pump pressure? You did not say what kind of general shape your rig is in.

 

A little slip lube in the right places makes a world of difference.

 

Have you checked the hydraulic system, over time it can get contaminated and can get water then when it gets cold, it slows way down. Also how long since you changed the hydraulic filter?

 

It is not a good idea to bump up your RPM in the cold, run the pump at the RPM it is designed for. All increasing RPM does is put more volume and pressure into the system than it is designed for which will lead to early failure of many components. If it is only one or two functions that are acting funny you may have a valve that is stuck or has caught debris in the bottom of it. You may also have some dry spots that need slip plate as said above, or even a cylinder with debris or a bad packing.

Are any of the slow moving functions showing any signs of leaking? How are the seals on the end of the pistons looking, especially the one that is sliding by itself with a car on it, sounds like either the valve body is sticking or the cylinder is leaking off.

One more though on cold weather, if the functions you are having problems with in the cold also move slower than the other functions in the good weather it may just be the design of the truck and the cold weather is just amplifying the slow down.

 

Did you figure out what was wrong? Having the same problem on a 2012 High rail