The only guy I knew using dub ambient glycol, and his was very sub ambient chilled by an air conditioner, killed like four or five D5 and DDC pumps because they just aren't designed for the viscosity of anything but water.
He went to the koolance PMP 500. It's noisy but has lots of power.
I see they also now have a 24v model with even more power in the PMP 600
What % glycol are you talking about? DDC pumps can handle up to 20% Anything more than that and i'd imagine you'd need some sort of magnetic drive pump. But beware, they can become incredibly expensive.