If your 98 is anything like my 96 there is a snap on safety clip retainer on the outside and inside the connection itself there is another lock/retainer clip with four expanding clips/tabs. Pushing all four tabs inword towards the hardline and disconnecting the coupling is almost impossible. There may be a help tool for this. I made my own with a piece of plastic tubing an inch or so long (with the ID of the plastic close to the OD of the hardline), cutting lengthwise putting it around the metal part of the line and pushing it into the coupling, pushed the locking tabs in, allowing me to disconnect it.
The old style had two visible plastic tabs, that could be sqeezed together by hand, the 96 has four tabs, deeper in the coupling, that are hard to see.
Let us know what you find, little things about and tricks of specific model runs are nice to know.