Good to see you're (probably) back in business - I share your OCD, sometimes to more of an extent than I'd like :laughing:
IF you want to understand QD's a bit better, here's one scenario that can happen (possibly yours)
The ag type QD's are typically either ball or "poppet" type, and both types have a common design flaw - both halves of a QD pair, whether ball or poppet, have a SPRING behind the sealing item (the ball) - this is the part that keeps MOST of the hydraulic fluid from ending up on the ground when they are disconnected.
When you put them together, BOTH halves' springs compress, allowing BOTH balls to move away from their respective seat, and fluid is then allowed to move thru the (restricted somewhat) passage AROUND the balls.
BUT....
If either one of the springs fails (breaks, or relaxes due to metallurgical failure) then that pair of QD's becomes either a partial (low flow) or TOTAL CHECK VALVE -
This will either partially or TOTALLY block flow, but ONLY in ONE direction - ("my cylinder will extend, but won't retract")
If you actuate the control valve to cause flow from the bad side toward the GOOD side, you WILL get flow because the pressure will push the GOOD ball and spring away from their seat.
BUT - going the OTHER direction, there is nothing but a broken (or weak) spring to push the GOOD ball/spring away from its seat, so NO (or little) flow.
There's more, but hopefully this will help explain what can happen and why it can get pretty confusing... Steve
