Hey everybody, had a quick question. We are looking at buying a 79 930 for farm use. It has quick tach, but no third valve. I was wondering how hard it was to add a 3rd valve, and what parts to look for. Thanks
How is the quick-hitch operated at present? The easiest way I know is to take a tee off the line that crowds your bucket back. The new line goes to the "P" port of a small lever operated directional control valve. The "A" and "B" ports of the new valve go to each end of the locking pin cylinder of the quick-hitch. The new valve has to be a closed centre valve i.e. the "P" port is blocked in neutral. This can be done by either having the right spool in it or getting one with a "high pressure carry over" and blocking the "power beyond" port. In either case it is vital that the Tank port of the new valve goes to tank. CAT machines are a pain to modify because of their extensive use of fixed steel pipework and 4-bolt flange connections. To operate, you crowd the bucket back all the way then move the lever on your new valve to move the locking pin one way or the other. That machine should have a fixed displacement pump and an open centre system as opposed to a closed centre, load-sensing type but it will still work anyway. Oh yeah, the relief valve in your new valve has to be set higher than your system pressure, otherwise it will relieve back to tank whenever you crowd back. Got it? Cheers. M.
I belive that machine has a balderson. Im not real familliar with them, but at the moment you use a hammer to drive the pins at the bottom in and out. Sounds like I need to look it over a little better.
I have a 12 volt hydraulic add on power unit that powers my quick attach or with a contol mounted inthe cab