I have a 977 L (48J) that needs to have a 3rd. valve installed, installing new is to expensive, the dealers around here can't find any thing used. What other options do I have or does anyone no of any place I can buy the parts I need used. Thankyou Jeff
What are you putting on it?
Brush grapple
I think I answered this question elsewhere,but to do this either go OEM(hard to find)or intercept the hyd flow from the pump,plumb it to a valve,then out of the valve to the stock Cat tank/system.You'll need 1.5"dia ported,4-bolt flange fittings and 1.5",4braid hose between the valves and tank as well as a 1"or better relief valve to go from between the new valve and the tank to dump any surges from the new valve.You'll also need hardlines to travel down the mast to the bucket area.Cat used 2 additional swivel unions for the 3rd valve to get from the loader chassis to the bucket mast,just behind the instrument panel in the engine compt.Maybe you can use 1/2"hose for the flex transition to the mast instead of the unions and hardlines.You HAVE to use the 1.5"valve inbetween the pump and stock hyd system or face serious flow issues..the stock 977 pump makes 88GPM at 1800rpm.I was gonna do tis on my 977-11K machine but it's a big hassle.You're almost better off finding a 977K/L that has a 3rd valve already installed and scrapping it for all the parts..tough to find stuff these days unless you buy all the parts 1 at a time..best of luck
Thanks for the reply, Already tried that , does not work unless you use the lift or dump valves at the same time. Is there any place I i could add a aux. hyd. pump on that machine, it would'nt have to be that big just for the 2 rams on the grapple.
with an open center hydraulic system it will flow into the circuit with the least resistance first..if you used an open center valve first in line before the Cat tank,it interupts the flow and sends the flow to that circuit until the relief valve opens.If you plumbed them inline with the appropriate valve it couldnt not work.
you
Look your engine over around the timing gear housings,Cats usually have 3-4 places you can add a pump drive,if you have a 2 bolt oval cover anywhere,you may be in luck,cat has adaptors for several different pump shafts,and pump mount flanges.For running a couple rams,this might be the easiest way to go if you have an open drive on the engine. A good place for a large 4 bolt valve is surpluscenter.com they have a few big Husco flanged valves rated at 80 gpm for cheap $$$,they are good valves too.
Mine had a third valve in the tank...never hooked up..may want to check
Thanks for the info , thought that would be the easy route to go
Pulled the cover on the tank, no luck. Thanks for the idea