Hydraulic valves I have 1991 Ford F450 with a Telsta A28D bucket or lift. My question is a kind of generic one. All the Hydraulics work. They are 12V electric to a series of 4 valves (rotation, lift, extend and bucket retract). Each works off 12V toggle switches to what I think is a solenoid that opens up the valves and applies pressure and / or relives pressure. I think this is pretty standard My concern is the motion ‘jerks’ when starting. I think there is an adjustment to slow down the actuation and smooth out the start and stop. Question: Ho does one feather in or adjust these? Is there a rheostat, or a pressure relief valve? I think there is a standard way to adjust this, but I don’t know what it is
The A28D does not have the ability to feather the controls. I would have to ask what is the outside temperature there? If you are trying to operate the unit with cold hydraulic oil that could be the reason it's jerky. Warm the oil up by running all the functions in and out a few times and then retest.
Cold outside Hi It is cold (by California standards) now. It is in the 40s and 50s. So you are telling me that heat in the hydraulic fluid would soften up the motion. Hmm, the fluid is pink and looks good, but I wonder if the fluid is 100% ATF or if there might be some hydraulic fluid at a higher viscosity (I assume heating the fluid would drop the viscosity). I wonder if changing out the fluid would help?
The Telsta does run ATF. With any hydraulic system you have to warm the oil prior to use. Does it seems to get smoother after operation? If so the oil is warmer and that was your problem.
Toggle switch control is common on these type of bucket trucks. And yes, the controls are pretty much on/off, no feathering. With boom fully extended boom swing can get interesting. On boom swing it helps to give the toggle quick on/off/on/off flips as opposed to dead on, this helps control sudden start and stopping with boom swing. Engine RPM has a lot to do with it as well. If the machine was set up properly, and if it's equipped with a Hi Throttle switch at the bucket, the unit should work nice and slow with engine at idle, then speed up considerably with Hi Throttle selected.