Kubota L4701 HST with BK976 backhoe
I have a Kubota L4701 with the BK976 “quick detach” backhoe. Everything works great except for the pioneering quick connect hydraulic fittings. After replacing 2 new female couplings for bent or broken, I still can’t get one of the connectors together without bleeding the pressure off the backhoe by breaking several of the cylinder hoses. I am doing something wrong? Is there a better way to do it?
You can put the BH in blocks so that there is no pressure in any of the cylinders. If there is pressure in the cylinders, the valve stack will probably leak a bit and then put pressure on the quick fittings. But even without that, if the ambient temperature rises significantly between the time the BH is removed and when it is put on, the expansion of the hydraulic fluid will make the quick fittings impossible to operate. Plugging the side connectors of the BH together when the BH is removed will not help that … in fact it will be difficult or impossible to disconnect them.
You can make a pressure relief device with a tee that has quick connections at two ends and a valve at the other. Plug that into the quick connects on the BH when you remove it and use the valve to release the pressure before removing the tee and plugging the BH into the tractor.
They make quick connections under pressure, but the ones I have require a lot more force to connect than normal ones. Maybe if they were on a bulkhead that would be usable, but with my BH setup the QCs are on the hoses and I can’t get them to connect.