: How to drain coolant? 1994 FWB.

11-30-09, 06:35 PM
Is there a guide online? I can't find the radiator cap, should I use the 4 gallons of 50/50 antifreeze on the reservoir? Thanks. I'm planning on using Prestone's Radiator Cleaner before-hand.

11-30-09, 08:25 PM
The easiest way is disconnecting the lower radiator hose, There is no radiator cap. Remove the cap at the pressurized reservoir next to the battery. You cannot drain all the coolant. All you can get is two gallons. After refilling, run the engine with open cap until the thermostat opens. Put the cap and carefully open a little air valve with a 7 mm wrench near the thermostat housing. Close it up when coolant stream comes out instead of bubbles. It may take two-three heating-cooling cycles before all air gets out, I put one tube of Bars Leaks Golden powder bougt at Wal-Mart inside the lower radiator hose . The FSM (factory service manual) recommends adding that coolant supplement.

I would not use any radiator cleaner. It will get all the crap loose. Just drain and refill. While there you might want to back flash the heater core through the disconnected heater hoses. Use a garden hose.

11-30-09, 08:34 PM
The reservoir should have a pressure cap on it; that's your radiator cap. Use Prestone 50/50 GREEN (unless your car has DEX-Cool orange, which it shouldn't). As for the guide, you can buy a service manual from eBay (http://shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1313&_nkw=1994+Cadillac+fleetwood+Service+manual&_sacat=See-All-Categories).