Are "Cadillac Tabs" worth it?

[rapidoxidationman]

The cooling system sealing tabs that look like they are pellets of sawdust. Buy 'em at the GM parts desk.

I've got some very slow weeps from my water pump and the O-ring that seals the back end of the pipe from the water pump to the back of the engine. Am I wasting my time in dropping 5 of these tabs into the cooling system (via the upper hose of the radiator)?

The leaks are slow enough to not leave any drops on the driveway, but "there" enough to show wet spots on the engine beneath the pump and beneath the back end of the pipe.

Opinions? I've got a new GM pump ready to install if the SHTF... Hate to spend the $40 GM wants for that 2" x 1/8" O-ring though...

[DmaxMaverick]

The Caddy tabs work very well, to do what they're intended to do. I don't think they'll work for what you need. O-rings seal very different than flat-type gaskets.

[Kennedy]

I think you might get away with it, but the problem that I see is getting circulation. They almost need to be dropped into a high flow area. You'd have to try. I'd just use 1 or 2 should be all that you need.

if you do go back into the WP project I recommend lubing the orings thoroughly. We use dielectric grease, but many use a product called super o lube. This way the parts slide free and there's less chance of it dragging and stretching the oring.