<html><body><div style="font-family: Arial; font-size: 12pt; color: #000000"><div>I'm going to answer my own question: the lubricant is for the seal, which is a ceramic against a machined metal surface (not the bearings, obviously).<br></div><div><br></div><div><br></div><hr id="zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br><div><br></div><div style="font-family: Arial; font-size: 12pt; color: #000000"><div>Oh boy! A 'hot' (pun intended) topic right up there with oil and tires ;)<br></div><div><br></div><div>'Coolant'--to my pedantic eye--is a mixture of water and antifreeze. The antifreeze is mostly ethylene glycol--some use propylene glycol, which is non-toxic but slightly less efficient--with some pump lubricant* and corrosion inhibitor. The corrosion inhibitor is a mild acid that gets 'used up' over time:<br></div><div><br></div><div><a href="http://www.google.com/patents/US6096236" target="_blank">http://www.google.com/patents/US6096236</a><br data-mce-bogus="1"></div><div><br></div><div>Usually, coolant life is expressed in miles; modern formulations can go over 100K miles before recommended change-out, but since our Healeys aren't going to be driven that much time becomes the issue (iron engines will rust just sitting). I would say change it every 5 years or so (which might only be a few thousand miles of driving for some owners).<br></div><div><br></div><div>I believe the 'waterless' coolants are mostly propylene glycol and are quite a bit more expensive than ethylene glycol formulations. You'd still need to change it out when the corrosion inhibitors get used up; IMO it's a gimmick.<br></div><div><br></div><div>Bob<br></div><div><br></div><div>* it just occurred to me that the only thing that needs lubricating in a water pump is the bearings, but the last thing you want in the bearings is water. Am I missing something?<br></div><div><br></div><div><br></div><hr id="zwchr"><br></div></div></div></body></html>