I have hoist cylinder safety valves on my Lulls. They are no longer available and new ones (new design) are 500+ each and I need to replace them in pairs I am told and then get new hoses and what ever is required to replace these old ones if I had to. It all comes in a kit from manufacturer butrather not spend 1000+ One had this little know broke off. No clue what it does but I think it may be seeping. Any way to seal it? There was a small o-ring below the knob when I took off the otherside to look. Knob is missing in center [img=http://img187.imageshack.us/img187/8376/hoistsafetyvalvebroken.th.jpg] You can see the knob sticking up from the safety valve from the otherside below. What does this knob do? [img=http://img513.imageshack.us/img513/3078/hoistsafetyvalvetopveiw.th.jpg]
That either has something to do with the pilot pressure ...or the flow ..... or a bleeder you maybe SOL unless you can find a equipment recycler ..... replace it only with the same part .... dont try to patch it . at least i wouldnt ..its all about liability today ..
When I took out the knob on the other side to look it has a tiny shaft on the end of the knob and the o-ring below it. The tiny shaft is still in there the knob just broke off. I did ask a few people who salvage these Lull forklifts with no luck.
I really hate to say this, but...that's ugly! First of all, that's an odd ball valve, it's an adjustable holding valve with external pilot, most valves today use internal pilot. That's why you have to buy new components to service it, those parts are obsolete. That is the holding valve for the cylinder. It works like a one way check valve. The boom up is the fitting on top, the valve allows oil to flow unrestricted into the cylinder to boom up. When you let go of the lever, the valve traps oil in the cylinder. In order to come down it has to be unlocked. When you move the lever to boom down, pressure goes to rod side of cylinder, but it can't move until pressure builds in the line that has a tee fitting and hose that goes to the valve body. When sufficient pressure builds, that line "unlocks" the valve to allow boom down. The part that's broke is the adjusting screw that adjusts how much pressure is required to unlock the valve. The only option you have is to somehow remove the holding valve cartridge from the valve body, clean the area where that screw goes into the cartridge, and give it a clean/quick weld around to seal it. Chances are the valves adjusted properly so you have no need to turn the now broken screw for adjustment, just seal with a weld. Replace the o-rings on the cartridge and give it a try. If this doesn't fix your problem, the valve is bad and your just up the creek. I hope that ain't the case for you.
THanks for the help again guys :notworthy:notworthy