I have a 2001 CRV EX. I am unfamiliar with ABS brakes and need some
advice. While braking on ice, there is a really loud clunking on
the front brakes. I realize that ABS tries to slow the rotor
without locking it, but this is ridiculous. It is almost like the
four wheel drive is working against the brakes. The dealer keeps
saying it is ice build up. This has been three times to the dealer
and of course I can't replicate it while driving with the mechanic.
Nothing of the sort happens on dry pavement, even under severe
braking; this is immediately after the problem on ice and then
moving to dry pavement. It will do the same on ice again
immediately there after.
Any advice?
Thanks

That's the normal behavior for ABS afaik. It's the fact that the wheels are trying to spin at the same time but by pumping the brakes (what the ABS is doing) on ice the tires are locking up and the rolling again, very rapidly. The ABS detect a difference in the wheels speed, applies more brake pressure, tire locks up, abs detects a difference in wheel speed, releases brakes, the abs detects a difference in wheel speed, applies more brake pressure, tire locks up, abs detects a differ....... this goes on until the wheels have either all stopped, or they found good traction, such as pavement.  I nearly had an accident during my first winter with 4 wheel ABS (any ABS for that matter) on my CR-V (Canadian Model). I was going down a snow-covered street which had a slippery layer of ice beneath the snow. This was downhill and met with the mainroad in my town. I pressed the brakes and the brakes went crazy, not wanting to stop the CR-V at all. I could steer, but I couldn't stop or even really slow down. I reached down and grabbed the parking brake and she slid to a stop quite quickly after plowing up enough snow under the wheels while having all four tires locked up.