My solution for hydraulic fitting protection, when connected or not, was invented to keep swirling snow and ice crystals off of the 4 connections for the loader lines, which are also the height and chute lines for the front snow blower.
Hot hydraulic fluid circulating in use melts snow on contact even when its -20C, and in no time freeze together tight the connections once the flow stops for a short while. I had to keep the ice and snow off the quick-connect sleeves or a disconnection battle was always inevitable.
So came up with using a 12" length of nylon protective hose sleeving, 1 1/2" ID size, slipped it over the female implement end fitting so to cover the connector completely leaving 1 to 1 1/2" past its business end, and zip tie the other end to the hose just below the fitting connection crimp.
When in use or not, the whole female fitting is covered completely by the woven nylon sleeve and zero ice builds up as there's no contact. They stay dry. Mission accomplished!
I am also finding out that all the female quick connect hose fitting remain dirt and dust free, and the male ends remain clean while in use as they're buried inside the protective sleeve too.
So now the dust covers and plugs you're fighting with like I used to are redundant, as the female ends are always protected. I tossed mine.
All it takes is slipping the woven cover back a few inches to expose the quick connect sleeve for color ID. Once it's time to connect, I grab the connector through the protector sleeve to engage the snap ring.
About 1/2" of woven fabric has unraveled with use on the sleeve ends as I haven't bothered to even try to hem or heat weld them to stop it. But my observation is the loose strands actually help with keeping dust and dirt out. I'll keep an eye if they unravel too much, but it looks like progress has stopped around 1/2". Good, because hemming them could be a bit of a pain.
Consider this my copyright claim to fame in describing the fitting protective cover, it's working exceedingly well and costs 12" of 1 1/2" nylon sleeve and a zip tie.
Should I market them?
LOL take it and run. Glad to contribute.
I'll update post with a photo, it's dark and chilly outside. L8R.