I'm having trouble on my T770 with the hydraulic couplers. To be clear, these are the ones where the attachment plugs in. I'm having to replace them about every 30-40 hours here lately due to internal leakage. When they fail a bucket or grapple won't stay open. It will close by itself and even when closed it doesn't hold any real pressure. The hydraulics on the machine are being worked hard. It's doing a good bit of running a disc mulcher and at times that mulcher does get stalled. Anything I should check? I'm using aftermarket couplers so does that mean they're junk?
Are both male and female ends from the same manufacturer? Are the couplers flat faced or Pioneer style and are they high flow? Internal leakage on the couplers sounds weird though. If you're losing pressure at the coupler, I think you should be losing fluid. I'm wondering if the problem is more in the control valve or cylinders on a grapple. A disc mulcher I would guess uses continuous flow and the aux. hyd. valve is switched on for continuous flow. A grapple only uses intermittent flow and would be in neutral when not being used. If the valve was leaking in neutral would describe the problem your having. Bad cylinder seals would cause it too or a leak in line somewhere but you'd see oil if a line was leaking. Especially if high flow the grapple cylinders could really get slammed open and shut in a hurry that wouldn't do the cylinders any good.
Seems like a low hour level for failure. I assume they are the floating, push assembly to relieve pressure, style, like the Faster 4FFi. Are the being fully installed with a 1-5/8" wrench? Are the seals damaged at either visible O-ring/ backup ring set? Are the fittings getting side loaded from too short, or poorly routed attachment hoses? You said "generic". Whose name and part number is on them? Can you verify that there is no bore damage in the manifold, where both seal sets reside (one for pressure and one for case drain)? Failures here are from drive offs and side loading.
Yes, these are the Faster style, flat faced. Summit is the brand. So far the other Summit products I've bought have done fine. They are being fully installed with a wrench. I don't remember seeing damage on the outer O rings but I haven't taken the current set out to inspect them (waiting on replacements). They are seeing some side load but not anything more than a typical hose setup. I will reroute to help this out. I didn't think to check the bores, thanks for that reminder.
It turns out the number is an FFH prefix from Summit. Is there a difference between FFH and FFi? The male coupler on the Bobcat side is the one that failed. The largest seal in there that's near the front gave up and it was leaking. I disassembled it and the other seals in there are OK. The bores in the manifold are fine and the seals that interface with those bores are also fine.
Are you talking seal in the flat face portion or in the portion that disappears into the manifold bore?
The one that disappears into the manifold bore. This is the seal that sees movement if you push in on the connector to relieve pressure. In this case a 38mm inside diameter wiper seal.