Q & A — September 2002
By Capt. Ken Kreisler
Neat & Clean
| How to service an oil cooler, getting rid of bugs in diesel
fuel, and doing a voltage-drop test.
First drain the engine oil and remove the oil filter. Disconnect the inlet and outlet lines from the oil cooler, and discard the sealing rings so that when it comes time to put everything back together, you won't forget to install new ones. Secure the cooler in a vise after you have padded its jaws to prevent damage. Don't overtighten the vise, as you may damage the cooler housing.
Now loosen and remove the through-bolt and discard the O-ring. Remove the front and rear covers, and discard these O-rings as well. Remove the cooler element from the housing, and examine it for deposits. Soaking the element in muriatic acid for about two hours will loosen up any such residue so you can easily remove it. Muriatic acid, available at any swimming pool supply outlet, is caustic, so wear gloves and protective eyewear. (Safe-React (404) 341-5313, www.safe-react.com, manufactures a product called Formula E that it claims is a safer alternative.)
soaking it, rinse the element with fresh water. If you notice solid deposits
still present, especially on the inside, gently scrape them off with a
half-inch-diameter dowel or similar soft tool. If there's excessive
buildup, soak the element for an additional hour and rinse it; you can
blow it dry with compressed or canned air. Insert the element into the
cooler housing, and install the front and rear covers with new O-rings.
Install the through-bolt and new O-ring and tighten securely. Reconnect
the inlet and outlet oil lines and new sealing rings, fill the crankcase
with clean oil, and install a fresh filter. Start your engine, and check
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.