Toolbert, is that sudden release dependant on load ? If not something wrong with it, but if it's like that at near max load, then that's pretty common....which is ironic as that is precisely when you most don't want it to do that !
On my 10,000 lb pallet jack, I got tired of the release being so jerky I contacted the factory and they send me a different needle valve for the pump. Once installed it's works much better...I can now release a 7,000 lb load pretty smoothly.
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Re the Jungheinrich announcement link...wow...I had no idea Multiton was part of Jugheinrich since 1976...I figured the merger was in the late 1980's or even more recent than that.