I have a quick coupler, its from a Cat 318 and it's been adjusted to fit on my Yanmar VIO 70. My question is what's the pressure needed for the quick attach to operate normally? I'm hoping someone with a cat manual source could take a peek. I have the pilot pump that makes 500psi or the main pump that makes a lot more. The pilot is a gear pump and a lot easier to intercept.
All my hydraulic couplers are driven off the boom curl circuit, including my Cat, Geith, Strickland, Yanmar and JRB. The only ones that I ever had that ran on pilot pressure were J.B.Hendrix. And, I doubt that it's from a 318. A 308 is more likely.
308 is probably right!! It was a while ago, popped up on ebay and was cheap!! bore the 45mm holes to 50mm and perfect fit for the yanmar. Possible then the pressure might be too low on the pilot circuit. Looks like it has a pretty good holding latch even if it looses pressure. I'll have to think about a diverter! How does yours operate?
They usually operate by teeing into the curl circuit, flip a switch to activate the valve, curl the bucket all the way and hold over relief, this diverts the flow to the coupler to release. Flip the switch again and it now closes the valve, and the coupler closes. At least this is the way I believe it works.
Typo above. They operate off the BUCKET curl circuit.
Do you have a photo of the quick coupler and cylinder. You could get any kind of coupler you wanted on any of the mini and midi excavators over the years. Someone will be able to recognize what you have and possibly direct you to the a pressure setting that would work.
Cat's hose routing...
Valve circled gets feed (P) from bucket curl (rod out) circuit, but part number is for 24v valve assembly. I gotta dig for 12v part number. (T) port to tank. Remaining two ports to coupler. Local chassis ground. Power via switch with buzzer in cab.
Valve assembly...
It can be a PSM, HPF, Hendrix and so on which might be a pin grabber like heymccall posted above or it code be a wedge coupler also made by all those people and PSM made a lot of couplers directly for Cat in both configurations.
Wow that's curious, so it takes pressure from bucket curl only. So flip switch and fluid is routed into the unlock piston and back to the tank. flip the switch to lock and curl pressure gets routed the other way to lock the bucket anytime that curl function is active.
Yes sir. Curl to relief is the hydraulic source. This requires a full curl to fully pressurize when electric is enabled to disconnect, leaving lithe attachment uncoupled while still gravity hung in the hear hook. And full curl to lock attachment, when deenergized, to secure attachment while gravity hung in both hooks.
Well that explains a little, there's a leaf spring that presses a lock down into a coarse ratchet of sorts, it must be the mechanical interlock. when unlatching the lock finger gets pushed up by the positive motion of the little piston in there. Even more simple, not diverting the line but just teeing into it?
Yes, you simply Tee into the bucket cylinder rod extend circuit. Typically with a straight adapter with a test port. Like these...
I have some of those for testing that'll be less complicated than diverting a giant BSPP hose I'm thinking of cheating and just running a 1/4 inch hose all up along the boom vs the nice looking hardline/flexline option.
If you have that type of quick coupler, you Tee in at the base of the bucket cylinder.
My old JRB couplers put the valve at the top of the stick (arm), needing only electricity out the boom, using the rod retract as the drain for the circuit, but...the valve and wiring always got damaged.
I seem to recall mounting a heavy box over the valve. It has been years now.
Tried that, too. If they didn't damage the valve, even armored, they ripped out the wiring. It was always the free wire at the boom to stick area.
I try not to smash stuff but it does happen, and it'll get a little warm during burn season, I'm happy with 2 lines running the stick and put the valve someplace under the seat