Brizo Model 63500 Faucet Hose Quick Connection is Frozen

[Michaelco]

I am trying to replace the hose on faucet, and it won't disconnect. I have removed the plastic clip that locks it onto the copper line, but pulling down on the fitting doesn't have much affect. There is a difference in the connector when comparing the replacement hose and the old hose. The replacement has a one piece brass fitting, and this one is either broken, or is a two piece assembly. In any case, the cylinder (or sleeve) which has a slot (that the locking clip engages) is free to slide down (see blue arrow in picture). I don't remember how this was when it was installed 12 years ago, and this may be normal (using tapers to aid the locking of the connection).
There isn't a lot of room, but I tried rotating the hose fitting (just below the blue arrow), with no luck. Tried squirting some vinegar at the top of the fitting in case there was mineral deposits - still no luck. I have thought of using a heat gun, but would need to protect a plastic piece from melting.
Looking for ideas on other things to try.
Thanks in advance.

 

[Marlinman]

The only thing holding the hose once the clip it removed is an o-ring. Since the oring has been in the same position since new it will take more force by trying to twist and pull down at the same time. Parts below.

 

[Sponsor]

 

[Michaelco]

The only thing holding the hose once the clip it removed is an o-ring. Since the oring has been in the same position since new it will take more force by trying to twist and pull down at the same time. Parts below.

I have seen the o-ring in the replacement hose. So, you think the o-ring is enough to make it difficult to disconnect - would heating up the connector help soften up the o-ring to make it a little easier to disconnect? I have used pliers on the hose end, to get a better grip, and applied quite a bit of force as I'm rotating the pliers - concerned I will damage the copper tubing - not likely to be an issue, or should I be cautious??

 

[Marlinman]

A small amount of heat will expand the outer sleeve and probably work. The o-ring is neoprene not rubber and can harden with too much heat.

 

[Michaelco]

A small amount of heat will expand the outer sleeve and probably work. The o-ring is neoprene not rubber and can harden with too much heat.

Thanks for the help - Don't know if the heat made the difference, or just the accumulation of all the rotating and pulling did it - but, in any case, replaced the hose and no leaks.
Thanks again