clutch fan

although I haven't used it for my car, I've bought citric acid cleaner for the coffee pot at Bed Bath & Beyond. You could try their website and enter "citric acid cleaner" and it will come up. It was under 10 bucks. Hopefully Big Block Mopar will fill you in on an approximate concentration and where he gets it...though I doubt you could add to much since it's biodegradable. You might try amazon/ebay also.