89 Sedan Deville Coolant flush

Hello everyone. I have a sweet 89 sedan deville w/ 60k. I love this car. Its been in my family since it was new and it lived a garaged life and was serviced by the dealer. My father had the car for the past two years and says it's had a slight radiator leak. He is also a freak about topping everything off. Right now the radiator has nothing but straight water in it because he would just top off the radiator resivoir every day. I continued this practice in september when I got it but then backed off. The coolant level stays constant now. Is it possible that it was just overfilled and the constant topping off caused the loss of all the coolant? I want to flush the radiator and get the correct mix in there before it gets hot again here in AZ, but i'm retarded and cant find the damn petcock.:banghead: Is there one? I have the Factory service manual for the car but it doesn't go into any detail on draining the radiator. It just says to do it as reg. maintenance and use some kind of tablets as a supplement (where do I get those). Any help would be greatly appreciated. This car has been so well preserved over the past 17 years, I want to keep it that way.

Well on my 93, I bought a flush kit and followed the directions on there. First, try to do the flush in the morning when the engine is completely cool. I didn't use the drain valve on my radiator but simply loosened the lower hose and let out the water after the flush was completed. I use only 50/50 mix all ready to go so I don't have to guess. You have to use the tablet as a suppliment in the radiator and you can only get these at the Cadillac Dealer...Really cheap but only use one per flush in the radiator. Do not put it in the overflow tank it needs to go into the radiator first and then pour the anti-freeze over the tablet. There will be air also in the system so you need to leave the flush port that you will install with your kit open until anti-freeze starts flowing out of the port then close it up tightly. Put your cap on and idle the car for about five minutes. Let it sit and then open the radiator cap again to let out the air ever so slowly because there will be some pressure in there. Top off again and also the overflow tank to the cold line. Put the cap on and drive it around for about 15-20 min. You will find that the tank will be low on anti-freeze and you will now want to top off to the hot line on the tank. Keep doing this until the level stops dropping. It took me three times to get it equalized.

I drained the radiator and flushed it with straight water like the service manual called for this weekend. The manual also says to remove the drain bolts on the cylinder block (two). Did you do this? I didn't, couldnt find them. The cooling system is supposed to take 3.25 gallons and it only took 1 gallon, so there was a ton left in the block. Is there any other method of getting all the coolant out of the block? Turns out I've got a large leak at the top left side of the radiator so I've ordered a new one and want to get the whole system clean when it gets here.

No thats it., disconnect the lower hose may get some more out.