I suspect the right type of peristaltic pump has a good chance of working. Many Air Conditioning units use such pumps to discharge condensate to the exterior of the building or to drain. Try looking on auction sites for "condensate pump" and you'll see many of these. Aspen are a common make, one of theirs is rated 288 litres per hour against a 4.8m head. This is ~4 litres per minute, which would suit many users coolant demand I would think. I have one of these pumps and intent to try it some time, the only concern I have is that the tube will wear if there is swarf etc in the fluid, so a good inlet filter is required. I would not suggest this for commercial/continuous use, but for hobby use I think its worth a try.
If there is an issue with the delivery flow being uneven, it should be fixable with a small head tank and overflow, this will stabilise the head and is nice and simple.
Chris
Edited By Jonesthenuke on 16/03/2013 16:25:13