Hello everyone,
I have a quad mast that drifts only in the middle of it's travel.( load or no load ). It does not drift, when I extend it up high, or lower it to the first stage. I at first suspected, that because they run around the wharehouse with the masts raised ( rug poles ) all the time, that the middle of the secondary cylinders must have excessive wear ( internally ). A gate valve test shows no drift what so ever while gated closed. Any ideas? I am baffled by this. I thought I really had a good idea with the worn cylinder theory.
Showing items 1 - 6 of 6 results.
replace packings in stage cylinders. Do them one at a time of course. Removal of cylinder necessary to replace lower ram seal.
i thought more about what you said about installing the gate valve in the line and the drifting stopped when you shut off the valve.
Another probable cause could be a bad check valve in the control valve?
Just a thought to consider next...
It is the two side cylinders that engage when the primary middle cylinder has extended fully extended...thanks for the replies.
It is a lifttek ( Cascade ) mast. I am constantly adjusting chains, because they stretch due to the constant state they are in ( elevated when driving and when parked ). I will definitely check this and set the chains by the manual. The drifting is very pronounced, you can hear it and almost see it. I havn't observed it long enough to see if it settles...but I will.
that a crown built mast?
or is it a lifttek mast built for crown?
from your problem description and test results it sounds like it may be a channel sequencing problem.
First thing i would do is check the chain adjustment on each section.
one section out of adjustment can cause this.
the drift your seeing might be the channels just settling down trying to equal themselves out. You will see it drift for a bit and then it stops?
Not familiar w/your machine- when you say quad mast- does it have 1 primary cylinder for the free lift & secondary outboard cyl's for the rest of the stages? The gate test usually shows- w/your results- a faulty hyd control valve.
When the drift occurs- which cyl('s) are contracting?
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